The Battery FAQ

By Hombre sin Nombre, Flash #412
Compiled & edited by Kristian #562
Updated by Scott, ID #1244
Please read the Disclaimer before attempting any work in this FAQ.
Last Updated: 13 June 2007, by Winter #1935

For other related FAQs:


Batteries are our friends. The design engineers cleverly put the battery right behind the hot engine and catalytic converter (on the Classic); and above the engine and next to the oil reservoir (on the GS). Toasty batteries are prone to drying out, so please check your 12 volt friend often, especially in the summer. It also noted that a dry battery is causing voltage regulators to go bad. Another good reason to check them often before they not only get the regulator but perhaps also the alternator.

I'm Confused! My Battery Has Died, What Should I get?

This is the short version of the FAQ... You can get a OEM replacement from most online battery sites, or most places that store a good variety of batteries. Just look for the YB12AL-A battery.

Many people also replace their OEM battery with an Absorbed Glass Matt (AGM) battery. There are two problems with the OEM battery. Firstly you need to check the water level regularly, and this can be a pain (especially on the GS/Dakar models). Secondly if you drop your bike, or the overflow tube comes loose, there is a chance acid will spill over parts of the bike and cause more problems.

The tables at the top of this FAQ list alternative batteries, and the experiences people have had with them. You will also find for each battery it tells you any specific modifications you may need to make.

Drop-In AGM is now available

BikeBatts in the US now offer a drop-in AGM battery - in other words no modifications to the bike are required. You will want to call Tim to ask for the battery. Unfortunately BikeBatts will not tell anyone where they get the battery (other than China), so we can not identify a supplier for other countries. We have no further details on this battery.

Note: This is not a YB12AL-A2 AGM battery, and it is not clear if it is an AGM battery or not (it may be a SLA). There is very little information on the specs of this battery.


This battery should fit in all F650 models including Classic, GS, Dakar and CS models. It is unknown what battery the G650X uses.

Warning: Check and Re-check the +ve and -ve Terminals!

When connecting a new battery, check and then recheck your battery terminals for the positive and negative polarities. Make sure they are around the right way. This is what happens when you don't:

I am so stoopid. I hadn't started my 02 GS in months, so the battery was dead. Went and got one that fit, came home, griped about German over-engineering the entire time I spent undoing all the stupid torx screws, and then fitted the new battery. 1.2 seconds after I connected it, smoke started pouring from the wiring harness. I freaked out and grabbed the fire extinguisher and gave it a squeeze. An anemic little trickle came out even though the gauge read full. Do I get to watch my bike burn to the ground?

After a few minutes, the smoke had stopped and I grabbed the screwdriver and disconnected the battery. It was then that I realized that the - and + terminals were on different sides from the stock battery. In one fell swoop, I turned my $6000 dollar motorcycle into a worthless pile of parts. I cried, I screamed dirty words at the heavens, I prayed to wake up from a nightmare. But here I am. With a 2002 F650 GS with less than 10k miles with a melted wiring harness. I am sure I killed the ignition too. OMG. It's something I have to have the dealer work on, and it's probably going to cost me upwards of a grand. Perhaps I should just sell it for parts. Sad

Moral of the Story: Check THREE TIMES before connecting the battery. And get your fire extinguisher re-charged TODAY! Do as I say, not as I do! clown shoes

Battery List / Battery Specific Questions

This section contains a list of batteries with links to any modifications you may need to perform to fit the battery to your bike. There are also some questions that are specific to batteries only, and are not directly related to the F650.

Note 1: The 12AL-A is a common battery size and can be bought many other places other than the dealership.

Note 2: For each battery, the top row are mm in Length, Width, Height and kgs in Weight, and the bottom row are inchs/lbs. All batteries listed are 12V.

Note 3: Amp/hr (AH) represents the total power stored within the battery; CCA represents the ability to start an engine under low temperature conditions (you could also view this as how much power can be delivered in a very short period of time).

Unsealed Batteries

Battery Dimentions (LxWxH) Wgt AH CCA Classic? GS? Other
Yuasa Yumicron
12 165 OEM OEM $34 + shipping from
BMW Part # 61212346420
Yuasa Yumicron
(OEM Alternative)
Post Connection has an Add on Clamp, but it can be used no Problem - k.)
Battery Web
12 165 YES? YES? A conventional "spillable" battery requiring dry shipment. Acid may be purchased locally (i.e. Sears stock #44000 @ $2.50).
Japan Storage Battery
(OEM Alternative)
Furukawa Battery
(OEM Alternative)
AC Delco
(OEM Alternative)
Magna Power
(OEM Alternative)
Autozone for about $52 before taxes
Interstate Cycle-Tron
(OEM Alternative)
(OEM Alternative)

Sealed Batteries

Battery Dimentions (LxWxH) Wgt AH CCA Classic? GS? Other

Absorbed Glass Matt (AGM)
Westco Battery
14 190 Tray Mods Tray Mods See CG Battery Deal!
$50 + shipping from Batteryweb
12 200 Tray Mods Tray Mods Will fit but can be tight in a GS
CNB model
? ? ? Tray Mods Chang Nan Battery
Deka PowerSport
14 190 ? Tray Mods BatteryWorld (Australia)
Sometimes labeled BigCrank
12 210 ? tray mods (method 3) ?

Sealed Lead Acid (SLA)
7 160 Hawker Hawker $86 + shipping from
Battery Web
Enersys Reserve Power (Powersafe)

Call U.S. Energy systems, INC, 1-800-582-5028, Ask for Darlene (19 Nov 2004)
Possibly no longer available.
See the Odyssey PC310 for alternative.
(See the Odyssey PC310)
Hawker Odyssey
7 100 See Comments See Comments This is most likely the alterative to the SBS8.
If anyone can confirm this that would be appreciated.
10 180 Not Recommended NO? A YTX12L-BS would be a better choice, it has the terminals that would fit best. (Around the right way).
See discount motorcycle battery
(Remove Tray AND Reverse Terminals)
Rebranded Yuasa battery. It fits the classic shelf with the rubber bootie and goes for about $75.
(OEM Alternative) I replaced my original battery (bought the bike 2/13/97) with an Interstate YTX12-BS for $70 in July before taking my 7K trip. The only way it would fit was on its end after removing the rubber box liner, and the wires will just reach. The battery does, as mentioned above, hold a charge MUCH better. Since returning from my trip on 9/20, I have ridden the bike twice - about 3-4 weeks between rides, and when I put the smart Charger on it day before yesterday, the needle flickered once it was apparently fully charged. This was, incidentally, the only battery my dealer could find at that time that would fit. Hal #15.
Hawker Odyssey
Hawker Odyssey
??? Prob does not fit

Battery Selection Questions

Here is a tip: A good place to compare battery designations, sizes and configurations is in the JC Whitney catalog ( Their battery section covers this in great detail. Once you know the battery codes that will fit your bike, you can go battery surfing, as I believe that they all use the same codes (such as YB12AL-A). The 12 is the battery amp hour rating. I believe the Y may indicate a motorcycle battery and the rest of the code describes size, terminal location and vent tube location. Richard #230, Pacifica

Terminal Semantics - Which is RIGHT and which is LEFT?

Are the reversed terminals on some Batteries hard to rectify?

Is the battery ground on the positive or negative side?

Is putting a SEALED Battery in Sideways (Stand it on End) OK?

OK thats a great list but I cant find any of those in my home town. What CRITERIA should I be looking for in a battery for the F?

There seems to be some confusion about batteries that fit the F. I have a list of batteries someone posted, but I don't know for sure if they are suitable. Well, you can't beat a good Yuasa! Criteria should be:

What is AGM and how is that different from Maintenance Free? Flash #412

Flash Dear Sir: Thank you for your email.

Wet Cell (flooded), Gel Cell, and Absorbed Glass Mat (AGM) are various versions of the lead acid battery. The wet cell comes in 2 styles; serviceable, and maintenance free. Both are filled with electrolyte and I prefer one that I can add water to and check the specific gravity of the electrolyte with a hydrometer. The Gel-Cell and the AGM batteries are specialty batteries that typically cost twice as much as a premium wet cell. However they store very well and do not tend to sulfate as easily as wet cell. There is no chance of a hydrogen gas explosion or corrosion using these batteries. Most Gel-Cell and some AGM batteries require a special charging rate, especially the deep cycle models. I personally feel that careful consideration should be given to the AGM battery technology for applications such as Marine, RV, Classic and Performance cars just to name a few. If you don't use or operate your equipment daily; which can lead premature battery failure; or depend on top-notch battery performance then spend the extra money. Gel-Cell batteries still are being sold but the AGM batteries are replacing them in many cases.

There is a little confusion about AGM batteries because different manufactures call them different names. A couple popular ones are regulated valve, and dry cell batteries. In most cases AGM batteries will give double the life span and many more deep cycles than wet cell battery. I hope I have answered your question. We have in stock the YB12AL-A.

Sincerely, Jose. Batteryweb

Is BMW installing sealed batteries in all bikes after 2003?

I think I read somewhere that BMW is now installing sealed batteries in their 2003 bikes. If this is also true for the new F650's, will the GS battery fit the Funduro? BMW batteries are expensive, but I'll bet they are less than Hawker. It might be worth checking into. Richard #230.

Various Battery Web Misc Comments

What about Walmart Batteries?

If so how did it work out for you and is it lasting. They sell one for 27.95 and that sounds like a good price, but I just wanted to know if anyone else had gone that route. Later, Dirty

How reliable are AGM batteries?

Has anyone heard of or used BigCrank batteries?

Modifications and Installation

This section is focused on proceedures to modify your bike for different batteries. Check the battery lists to see what batteries you could you, and click on the link to see the modifications required. There are also a few other modifications related to drain tubes.

Battery Removal - Disconnecting and Reconnecting

Supertech, Brian#179, Andy #982,

Here is the GS Battery, exposed.

Q. Can I access the GS Battery without removing the RHS AND Centre Panels?
Sure. See the GS Fairing FAQ.

Fitting a Westco in a Classic

GS/Dakar Tray Modifications

Fitting alternative batteries in the GS/Dakar is a little harder. There is not much spare space where the battery is, so you can try one of these modifications. There are two basic methods: The most common is to re-drill the holes in the metal tray. An alternative is to bend the metal tray.

Method 1 (by BradG#1002)

Here is some information on converting from an OEM Yuasa battery to a Westco 12V14L-B in a 2001 GS.

Method 2 (by Scott, ID #1244)

Here is some information on converting from an OEM Yuasa-compatible battery to a Westco or other AGM (12V14L-B compatible) battery in a 2002 GS Dakar. While some users claim the "maintenace-free" battery will fit in a GS battery slot, I found mine would not: the OEM battery fits snug as it is, and the AGM is wider by 5/16-inch (Length and height are of no concern. For the record, my AGM battery is a CNB model CBTX14AHL. It measures 5 5/16L x 6 9/16H x 3 1/2W. The OEM measured 5 3/16L x 6 5/16H x 3 1/16W.)
Looking at the situation, it seemed to me that a guy/gal could remove the metal bracket that the battery sits on, and by drilling new holes, essentially slide the vertical part of the bracket forward. This would make the width of the battery chamber wider. See below image; green arrows point to red dots that are the new holes (one hole is hidden from view):
  1. Remove seat. Remove the center tank panel, and the right side panel. Remove the battery (negative terminal first).
  2. Remove the two lower airbox screws (the ones that are located below the front part of the seat). Remove airbox and let it hang to the right side. I also removed a hose from the bottom of the airbox, to make it easier to get to the bottom side of it. This may or may not be necessary. Place a rag in the throttle housing opening to keep stuff from falling into it. (You WILL drop something in there if you skip this step).
  3. Using a torx driver, remove the screw from the plastic relay cover. Remove relay cover.
  4. Using a socket, remove the two nuts that hold the metal bracket near the plastic relay cover.
  5. Using an allen wrench, remove the screws (part number 8 in the diagram) that hold the plastic battery tray to the bracket. You'll find that the nuts (part 11) are spot-welded(?) to the metal bracket. Place the bracket in a vice, and using a chisel and a hammer, knock off the two forward nuts (leave the rear alone as you will not use this anymore).

  6. Measure the difference in battery widths. My new AGM was about 5/16" wider. Alternatively, if your OEM battery does not completely fill the battery slot (i.e., there is slack room), set the new AGM battery in the slot and note how much room is needed to make it fit (as shown in the photo to the right; photo and idea courtesy of fellow Dakar rider dmemt #1464):
    Measure the difference in battery widths. My new AGM was about 5/16" wider. Alternatively, if your OEM battery does not completely fill the battery slot (i.e., there is slack room), set the new AGM battery in the slot and note how much room is needed to make it fit (as shown in the photo to the right; photo and idea courtesy of fellow Dakar rider dmemt #1464):

    Using some loctite and lock washers, re-attach the plastic tray to the bracket using the new holes. Notice that the rear-most hole is useless now, so you will be using just the two forward allen screws and nuts (unless you want to run a screw through the edge of the plastic tray; I figured 2 screws is enough)

  7. I didn't actually confirm this, but visually it seemed that the upper part of the metal bracket will now extend INTO the plastic relay housing on the right side: the whole thing is now shifted forward almost 1/2 inch, and it was almost touching the housing before this operation. Given that assumption, I trimmed away the lower part of the plastic cover, cutting along the line shown below (I carefully used a bandsaw; a pair of wire cutters, etc. might also work just as well, and would be safer.)

    Alternatively, you could also cut off 1/2" or so from the upper ends of the metal bracket, through the old bolt holes; I prefered to leave them intact. (see "feedback" below; dmemt's method didn't require modifying the relay cover as he didn't shift the bracket as far as I did).

  8. Now that the bracket is re-attached to the airbox, remove the rag from the throttle housing, and re-install airbox to the throttle. Notice the snorkle end of the airbox needs to slip into a small hole near the headlight. Also, If you removed that hose from the bottom of the airbox, plug it back in before installing.
  9. As you install the airbox back onto the throttle, the two new holes in the upper part of the bracket will be slipping into place over the mounting bolts. Notice that your rubber battery retaining strap needs to be installed at this time: the metal clip it hangs onto will now be pushed forward against the bike frame, and cannot be installed later! (on the upside, it will never again come undone the next time remove the battery!) Notice the new gap along the forward edge of the tray bottom: this is the new width you just created for your new battery! Install the two lower airbox bolts. Install the plastic relay cover.

  10. Install the new battery, postive terminal first. The negative battery cable on my bike did not fit the battery very well, so using a round file file I enlarged the copper hole a little. After a minute of filing it slipped right into place.

  11. Install right side tank panel and center panel. Install seat. Set the clock and take your battery for a ride!

Start to finish, I spent 1-2 hours working on this. The AGM seems to run almost 0.5 volts higher than my OEM wet-cell. Also, it has about 30% more cold cranking amps. (about 215cca vs 165cca.) My bike now starts much faster than it ever did with the OEM-type wet-cell batteries. And as a bonus, I don't have to worry about checking water levels every week! Scott, ID, #1244

Method 3 (by dmemt, #1464)

Just thought I'd do a quick post on how I fit a Yuasa YTX14AHL-B2 into my battered Dakar. Basically, I just drilled all 5 of the stock bracket holes 1/4" back from the originals, ground a bit off the front right bracket tab for clearance, and flattened the front hold-down tab a bit.

A few tips:

  1. The nuts on the bottom of the bracket are epoxied on. I "broke" them loose with an 11mm box wrench and a hammer.
  2. A drill press would have been helpful, since the new holes overlap the old holes by a couple 32nds. I wound up with something more like slots when I was finished butchering the plate, but it still seems to be solid.
  3. To flatten the front hold-down tab, I hooked the strap over the tab, then hammered it vertical. It still comes on and off, but I wouldn't want to "fish" it on now. I'm not sure if there is room for the thin airbox foam rubber pad that the back of the stock battery rests against. I'd removed mine earlier while trying to figure out what would work, and there may be room to leave it in there.
  4. Top panel clearance seems to be fine. The battery/oil tank/airbox assembly is still "floating" above the frame on the right side. There doesn't seem to be as much battery vibration isolation as stock, but hopefully the new battery can take it. I'll have to check for contact wear after I do some off-roading, but I don't anticipate any problems.

Note: In TWO instances the YTX14AHL-BS has been installed with minimal changes:

Method 4 (by billmallin, #1629)

  1. I read Scott's post about installing his battery in his GS and ordered myself one. I installed it today while doing my 12,000-mile service. So, I was fully prepared to do the modification like Scott did, but when I got to looking at it closely, It was about 1/4" too wide, but it appeared it would go in there.
  2. It looked as if the bottom of the tray was wide enough, but the top was a bit too tight. So I simply took a mallet and bent the metal tray with a few strategically placed hits (see arrows in diagram).
  3. Hint 1: I took out the bracket and removed the plastic part bolted to the bottom (you know, that plastic deal that holds the snorkel to the air box).
  4. With a piece of wood under the bracket on the floor and rubber mallet in my hand, I kept tapping it until the battery fit. Tap it, try it. Hit it, try it. Smack the crap out if it, try it. And so on until it fit.


Any problems with the oil reservoir melting the side of the battery?

(Assuming outright melting isn't an issue, is there still any reason to think the lack of space around the larger batteries might cause heating problems for the battery?) Dano PDX #1164

Hawker (SBS8 and PC310) Sealed Battery

Odessey PC 310

Has anyone had luck installing the SBS 8 in a 2002 GS (looking through the forums it looks like artyom66 did in 2003)? If so how were you able to do it? apostate #1618

For those of you running the Hawker with the Touratech adapter: Does the adapter just fill the extra space, or is it also needed to make the electrical connections work? In other words, would running a Hawker with a home-made adapter be a decent option? Dano PDX #1163

Exide / Yuasa Sealed Battery

GS Charging Access

GS Battery Drain Tube

There is a little tube that runs from and overflow outlet on the right side near the top of the battery (F650GS, but classic also has this tube)). Is there supposed to be a small hose clamp on this? (Mine has no hose clamp). The tube either slipped off the battery by itself or the BMW tech who did my 6k service forgot to put it back on (while he was busy mis-routing my throttle cable and stripping threads). The result being a fair amount of battery acid leak on to the negative wiring harness and a few other places. I did some good off-road riding, and that's when the leak happened. Normally the overflow tube would carry the acid down under the frame and safely away. So, do you see a little hose clamp on there?

Hooking Tender to Alternator or Battery?

Alterative CS Batteries

General Questions

Finally, this section contains all the other questions about batteries. So if your question is not about batteries only, and is not about modifying your bike for a new battery, your question should be answered here.

Battery Maintenance

This bike will EAT your battery unless you check the level of the electrolyte frequently. Check it at LEAST monthly. Some try to remember to check it after every few tanks full of gas. EDTA can make a battery last forever IF you keep the electrolyte level up.

My Battery seems to be low on water. What shall I fill it with?

What about that Acid in a Bottle? If a battery is low on water, why can't battery acid be added instead of water?

How do I put water in those Tiny Holes?

Can I add water with the battery still connected?

While doing my routine 1000 mile battery top off, I was surprised to find several cells almost dry. This is unusual. Whats happening?

What about more details of Battery Maintenance?

What about the Battery Overflow Tube?

The terminals on the GS come loose easily. Is this normal?

What's the Story with the squashed GS Battery Vent Tube? How do I fix that?

What do I do if the battery terminals break?

When replacing the battery, both terminals partially broke. As I applied fairly normal torque to both bolts (lubed with dielectric grease, a little tighter than hand-tight), a side of the circle that the bolt goes through opened up. In other words, the "O" that the bolt goes through on the battery now looks like a "C." What's with that?

Is there any way to check for a DEAD Cell?

Can you (safely) add water to a charging battery?

How do I clean up acid spills?

GS battery check - can it really be that difficult?

I can't find this in the FAQs so perhaps someone can help me out. Is there a way to check the fluid level in an '05 GS battery without a) having to remove at least two pieces of cowling and b) remove the battery from the bike? I tried shining a torch through the battery to check the fluid level but without success. In theory there is no need for me to check the levels right now because the bike has just had its first service - but I wouldn't want to rely on the workmanship - see comment below re brake pedal. Lep

How do I remove the battery from my CS?

  1. To remove the battery from the Scarver is not fun. You have to remove the left ''fence'' (the left thingie you need when you lock a helmet to the bike, using the ''spider''). You have to remove the left large side of the bike, the plastic, and you have to loosen the left flasher.
  2. Pull off the rubber belt on the battery, remove -screw, lift the battery up and remove the +screw, and ta-daaa the battery is out! Keep an eye on the breath hoose, and put it back where it was when you put the new battery in.
  3. To put the battery in is even less fun, and do not do this outside on gravel, because I guess you are going to loose screws, and it is easier to find them inside!
  4. I bought one of those magnetic thingies that look like an antenna, to pick up small metal parts; I needed it when I had the battery out last year! And you need a low blood pressure, and some time, for this job. Liv, Norway

Should I grease the battery terminals?

What if I overfill my battery?

Battery Charging

Note: For Quick Direct Access to the Terminals see the GS Fairing FAQ. Many Charge through the Accessory Plug, but read cautions below.

I bought a new battery. I need to charge it up. What current should I use?

Can I charge it through the Accessory Plug?

How long should it normally take to charge the battery on a Battery Tender?

I fiddle with electronics. Is there a Battery charger schematic anywhere?

My Battery Water is always Low. I suspect the VR is overcharging the System. Is there a solution?

Can I start a Motorbike with a Flat Battery using a Car Battery?

Adding water to battery. I noticed my battery ('99F) was near the low line. Should I ride for an hour, or so, to charge up the newly diluted battery acid, or can the bike sit overnight or for a day or two?

How do I use a Voltmeter?

Do you have any more information on the F's Charging system?

What is best way to make Battery Charging Access?
Do I have to disconnect any battery wires to charge it?
Can I jump-start my bike (without removing the faux tank)?

Is it okay to charge the battery on a GS/Dakar/CS bike (with an FI computer)?

Does an AGM need a battery tender?

Do I need to remove the little caps off the cells when charging the battery? (When I was a kid, I remember watching my dad charge his car battery and he always took the little caps off the cells when charging) Fizz

Battery never fully charged?

Can the battery system handle a 500mA AA battery charger?

Can I charge my iPod overnight from the bike?

Battery Tenders

Battery Problems

Is it true to say the Voltage Regulator (VR) will be stressed and eventually fail if the battery is not kept topped up? For more information on the Voltage Regulator, see the Voltage Rectifier FAQ.

Is the converse also true that a failing VR will empty the battery?

Can I disconnect the battery while the bike is running?

When I try to start my bike IS the Tic Tic Tic sound coming from the Solenoid, (Large Round Object just Rear of the Battery on the Airfilter Cover with two big red wires coming out of it) symptomatic of a Flat Battery?

My bike will not start. When I turn the key to the on position, there is a buzzing sound... Turned the key off, no buzzing, turn it back on without touching anything and it is back. Push the starter button and the buzzing stops and the lights dim.

I'm having problems starting the bike. Could it be the Battery?

My ABS light came on while riding and stayed on. Now the bike won't start!

Stalling, difficulty starting and hesitation when applying generous throttle?

Can a battery get too weak to start after only 12 days of non use except for a quick 10 sec. start to move to from the driveway to garage?

I ask cause I just came back from a quick night ride. I haven't been riding and was wired. Figured I was due a short ride before I went to bed. Anyway my bike wouldn't start. It kept cranking but wouldn't catch. I left it for about 10 seconds then tried it again and it finally turned over. They way it sounded when it turned over is like like it was almost at the brink of turning over then it just caught. Sorry I can't explain it any better. Oh yeah...The bike is only 3 months old. That is why I am surprised. Should a battery tender be purchased in my near future?

If I've allowed my Battery to Drain Water/Get Low (Due to e.g. VR Problems, Poor Maintenance), will it ever fully recover?

Ever heard of a sudden battery failure? Sudden Battery Death? Battery Suddenly Died?

Pop! Smoke! Dead Dakar! - (battery area - anybody had it happen?)

Is it possible for a brand new battery to go bad, or might there be another reason like a short somewhere?

My bike is dead (no headlight, brakelight etc), but a multimeter shows the battery is good.

What are the normal voltages of the battery?

Battery life when riding short distances?

Can a battery tender "boil off" a wet cell battery?

What would cause a battery to bulge?

Do I need to do the Flay to keep my new battery in good condition?

Can I remove my Battery while the bike is running?

GS clock reads funny when inserting a new battery?

Getting Home With a Dead Battery

See Can I Push Start a GS first.

Battery Life


What on earth is EDTA?
Pb is the symbol for lead on the periodic table. Your battery gets a certain amount of lead in its plates when it is new. Some of that dissolves into solution when you pour in the acid. Some of it turns into lead sulphate when things are not working quite right. (Adding EDTA prevents that.) If you allow the extra liquid to boil off the lead stays in the battery. The liquid does not actually boil in that it never gets that hot. It DOES electrolyze into hydrogen and oxygen and the vapours go away. Anyway, if the lead stays in the battery, you haven't lost anything when the level draws down except for water, which you happily add back in (in the form of DISTILLED water). Removing electrolyte is not a good idea. There is Pb (lead) dissolved in the electrolyte and you'll diminish the capacity of your battery by removing it. The battery on the F boils off electrolyte fast enough that it won't be overfilled for long.

The EDTA somehow keeps lead sulfate from forming (or keeps it soluble). The lead sulfate is formed from the lead + the sulfuric acid in the battery. Lead sulfate is insoluble in the electrolyte, and sinks to the bottom of the cell when it flakes off. When the pile of lead sulfate gets big enough, it bridges the gap between the plates, and you get a dead cell. If it doesn't flake off, it reduces the effective surface area of the cell, slowly reducing its capacity.

EDTA works by binding divalent cations (lead in this case) therefore inhibiting the formation of lead compounds. For already formed lead sulphate...the reverse reaction is probably enhanced (not sure). Tetrasodium-EDTA is relatively water soluble compared to disodium EDTA. If you dissolve it in water first you can then add it to battery electrolyte which is approx 4M sulfuric acid. I don't know how long it stays in solution. If you dump the powder straight into the battery very little will go into solution. If the 'powder dumping' approach yields results it suggests that very little is actually needed. As per Google, In general, use one tablespoon per cell in a golf cart battery such as a Trojan T-105. There are approx. 40 tablespoons in one pound. George#384

See for a heap more information on EDTA.

EDTA - a Critical Voice (long) - from OyvindSn, Norway
I posted a question regarding EDTA as a battery preserving agent on a boat-related newsgroup some time ago. A gentleman by the name of Frank Wentzel replied:
(For the entire discussion, go to EDTA - a Battery Preserving Agent?

I spent over 20 years in the battery industry, starting at the Exide battery research center in Yardley Pennsylvania. Battery additives and rejuvenators have been a hot item as long as batteries have been in existence.

Sulfation is the most often mentioned failure mode that these additives are supposed to correct. The problem is that the formation of lead sulfate is the normal manner in which a battery delivers its energy. The active materials in a charged battery are PbO2 (lead dioxide), with a valence of +4, in the positive plate and a porous form of lead called sponge lead, with a valence of 0, in the negative. On discharge the active material of both plates becomes lead sulfate (PbSO4) with a valence of +2. On charging the lead sulfate is converted back into the respective active material. Both the PbO2 and Pb on the plates are conductive, the lead sulfate discharge product is essentially non-conductive. As long as the crystals of lead sulfate formed during discharge are very small, their proximity to conductive portions of the plate permits them to be converted back to active forms. Destructive sulfation occurs when the PbSO4 crystals become larger and more difficult or impossible to be converted back into active material.

This occurs through a phenomenon called Ostwald Ripening. OR causes crystals to become larger over time. The best way you can see this would be to take a small jar of water and add sugar till no more will dissolve and then add another spoonful or two. At first when you stir it the powder in the bottom will swirl around easily. By the end of the day a crust will form on top of the sugar so the powder will no longer swirl. In a few days you will see crystals growing. Over time they may get to be a quarter inch or more in size. In your battery the PbSO4 crystals will be quite a bit smaller, but if you were to take apart a sulfated battery and dry the plates you would see them sparkle as light bounced of the crystal faces.

This sulfation is essentially irreversible. Battery manufacturers have tried to combat it since the beginning of the last century. Besides tying up active material the, sulfation also consumes the sulfuric acid electrolyte. As the battery degrades the acid concentration drops and the internal resistance of the battery goes up. This rise in internal resistance further limits the power output needed to start your vehicle. Most battery additives act to decrease the internal resistance which means that, for a limited time, you can more efficiently access the remaining power in the battery. Depending on the application (initial condition of the battery, power requirements, temperature, etc.) you may get anywhere from a week to several months of additional use out of your weakened battery.

One of my first jobs when I joined Exide in 1969, was to analyze a new battery additive called POW'R. When I complete the analysis I discussed the results with one of the Old Timers who had been designing batteries for over 40 years. The major ingredient was magnesium sulfate (MgSO4) otherwise known as Epsom salt. He said Epsom salt was the old standby for additive charlatans. It gave a quick reduction in internal resistance but could do nothing to renew an ailing battery. There was enough cobalt (Co) in the additive to give it a blue color. My friend said that cobalt would reduce the voltage required to charge the battery which might help if the car's charging system was weak. The downside was cobalt also causes the battery to self-discharge more rapidly and accelerates corrosion of the positive grid. There was nothing else of any value (?) in the stuff. At the time it sold for $7 a bottle (maybe $30 adjusted for today's inflation).

At that time I told him that a lot of people thought it was possible to make a really long life battery but that the battery companies didn't do it because they wanted to keep sales up. He said there were 5 major companies. The company that could find a way to make a demonstrably better battery (for a price) could blow the others out of the market. If you could dominate the market why would you sit on the idea? He said that he could make me a 15-year car battery The only problem was it would cost five times as much as current batteries and weight 250 pounds.

As to EDTA in batteries, it will increase conductivity of the electrolyte, which may give you a brief reprieve as noted above. In addition, it may increase battery capacity for a time. As a salt of an organic acid EDTA will again become an organic acid when placed in the battery. Organic acids readily attack the metallic lead of the positive grid structure. A small amount of organic acid can consume a large amount of lead grid because the reaction recycles the acid back to its original form to continue the attack. The corroded grid material will be able to withstand a few charge-discharge cycles but will fail fairly quickly. Over time (dependent on depth of discharge, frequency of use and temperature) the positive grid will corrode through and the battery will fail.

In other words, a battery that is close to failure might be brought back for a limited amount of time. That will give the battery a chance to finally fail just when you need it most! If the battery is known to be weak, it is best to replace it as soon as possible rather than hoping you won't be in the middle of a serious situation when it does fail. The only valid use I can see for battery additives would be to have some Epsom salt in your tool kit so that you can try to get one last start out of a bad battery when caught unaware.

Epsom Salt. The FAQ (battery section) mentions that it is a good idea to bring in a long trip some Epsom salt with you in case the battery dies. It seems that adding the salt to the electrolyte can give you some extra life in case of an emergency. Since the salt is cheap, has multiple uses and can be found in any CVS/Walgreens/Osco, I was thinking to add a small ziplock with some salt to my spares. Any experience with that ? Which quantity should I add to each cell ? What's the chance I'll end up in jail if a cop finds me with a small ziplock full of white crystals?. My idea is not to rely on the magic properties of the salts, BUT a small ziplock takes no space in the tool bag. My assumption is that IF I am stuck in the middle of nowhere and the couple of grams of salt I have in my tool bag can give me an extra kick to get to the next gas station. Why I shouldn't try using them ? Thanks Giovanni '97 F650, Waltham, MA.

Note: In some states / countries, the adding of epsom salt (or for that matter, other additives) to batteries may be illegal. Ensure you follow the manufacturers instructions and all appropriate laws. But this was common sense right?

External Battery Links

Order will grow out of confusion... Winter