The Ugly - Battery Melt down?

Hi All,

Here is the ugly portion of today's postings. Maybe 9 months ago, The Bro and I slid a Battery Mat (yellow with red printing of batteries) from BavAuto Part #BM812 under my battery. When I last looked under the hood maybe in Oct., the mat looked normal. it had collected a little dirt dulling the yellow color a bit - no big deal. Yesterday while changing the headlight, I noticed that it looks really bad suddenly. White powder residue is collecting long the edges. I don't know if this is normal for batter mats or if the battery is leaking now.

I can't find a good web link for the BavAuto Battery Mat #BM812, The copy reads "The Battery Mat is a practical and inexpensive product made of super-absorbent, long lasting polypropylene felt, it sits underneath the battery to absorb and neutralize any acid that might escape. Prevents corrosion and costly damage." If you run a search on BavAuto for Battery Mat, then you'll find it.

Here in SF, we've had a lot ot rain recently. Could the white power residue be a result of rain water? (Hood is almost always in the closed position - especailly when it rains.)

Here are the pics. There are also some dead leaves near the bottom of the battery.

Battery Crud 1


Battery Crud 2



Do I need to replace my battery ASAP? What should I do?


Thanks 1,000,000 , Kelly :-)

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Kelly
Hi All,

Here is the ugly portion of today's postings. Maybe 9 months ago, The Bro and I slid a Battery Mat (yellow with red printing of batteries) from BavAuto Part #BM812 under my battery. When I last looked under the hood maybe in Oct., the mat looked normal. it had collected a little dirt dulling the yellow color a bit - no big deal. Yesterday while changing the headlight, I noticed that it looks really bad suddenly. White powder residue is collecting long the edges. I don't know if this is normal for batter mats or if the battery is leaking now.

I can't find a good web link for the BavAuto Battery Mat #BM812, The copy reads "The Battery Mat is a practical and inexpensive product made of super-absorbent, long lasting polypropylene felt, it sits underneath the battery to absorb and neutralize any acid that might escape. Prevents corrosion and costly damage." If you run a search on BavAuto for Battery Mat, then you'll find it.

Here in SF, we've had a lot ot rain recently. Could the white power residue be a result of rain water? (Hood is almost always in the closed position - especailly when it rains.)

Here are the pics. There are also some dead leaves near the bottom of the battery.

Battery Crud 1


Battery Crud 2



Do I need to replace my battery ASAP? What should I do?


Thanks 1,000,000 , Kelly :-)

Hi Kelly,

Happy Festivus B)

Don't worry about the battery too much; but if you are, you can have it tested.
The residue; actually corrosion is not from your nice mat but rather the product of battery acid reacting with the metal pan everything is sitting on. You can see it is heaviest right below the vent pipe on the top side of the battery.

The battery acid and moisture work to produce an electrolytic action that deposits mineral from the battery plates onto the metal shelf.

Not sure how to stop this other than putting a longer vent drain hose on to direct any emissions, from the battery, to an area that would be non reactive.

In the mean time, remove the battery, clean and scrap as much of the crud off then give it a nice bath with a slurry of baking soda. This will neutralize and disolve the remaining crud. When all is clean, cover the tray with a thin coating of grease; this will help to prevent further build up.

Good luck

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Archeo-peteriX

Hi Kelly,


In the mean time, remove the battery, clean and scrap as much of the crud off then give it a nice bath with a slurry of baking soda. This will neutralize and disolve the remaining crud. When all is clean, cover the tray with a thin coating of grease; this will help to prevent further build up.

Good luck

Hi P,

Cool. Thanks for the good advice.

Do you think the mat is still good or is it burned out now? Should I buy a new one - is it worth the $6? (I'd think yes.)

Do I wash it in the clothes washing machine with some old rags?

How does the battery acid and plate minerals escape from the battery's plastic case?

Thanks, Kelly

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Kelly

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Archeo-peteriX

Hi Kelly,


In the mean time, remove the battery, clean and scrap as much of the crud off then give it a nice bath with a slurry of baking soda. This will neutralize and disolve the remaining crud. When all is clean, cover the tray with a thin coating of grease; this will help to prevent further build up.

Good luck

Hi P,

Cool. Thanks for the good advice.

Do you think the mat is still good or is it burned out now? Should I buy a new one - is it worth the $6? (I'd think yes.)

Do I wash it in the clothes washing machine with some old rags?

How does the battery acid and plate minerals escape from the battery's plastic case?

Thanks, Kelly

Kelly,

The mat may still be good; just wash it with a little soap and water in the sink. Use some baking soda for stubborn build up. If it still looks presentable, keep it. If not I'm sure Beemie will appreciate a new one...for $6 it's hardly worth worrying about the old one

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Kelly
How does the battery acid and plate minerals escape from the battery's plastic case?

In your second photo, Battery Crud 2, look at the top surface of the battery that has the sticker saying "Danger/Poison". There are six round plugs with + shaped crosses on them. You can use a screwdriver to open or close those plugs to add acid to the battery cells. Make sure they're all tightly closed.

Then, as Peter indicated, on that same top surface there are two vents, one pointing outboard, the other pointing inboard towards the engine. The outboard one is likely plugged shut, check to make sure it is. The inboard vent can be seen in your photo directly above the black woven carrying strap for the battery. It has a 90-degree elbow stuck into it with an open nozzle pointing downwards.

The vent is necessary because, when the battery is being charged by the alternator, the acid bubbles off hydrogen gas. That must be permitted to vent safely out of the battery. It's the reason why you should never expose the battery to an open flame or sparks while it's being charged or being boosted with jumper cables, as the hydrogen can ignite and explode the battery, showering you with battery acid.

Unfortunately as hydrogen is normally vented from the battery, it can also spit some acid from the vent. That 90-degree elbow really should have a rubber tube connected to the nozzle, routing any spilled acid down to drip safely onto the road and NOT onto any of the metal bodywork.

My 325 has the battery located in the trunk. The rubber tube from the battery vent leads down below the battery tray into a small plastic tank that collects any spilled acid before venting straight down through a rubber grommet set in the bottom of the rear fender. See #12 and #11 in this RealOEM drawing.

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Ferdinand

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Kelly
How does the battery acid and plate minerals escape from the battery's plastic case?

In your second photo, Battery Crud 2, look at the top surface of the battery that has the sticker saying "Danger/Poison". There are six round plugs with + shaped crosses on them. You can use a screwdriver to open or close those plugs to add acid to the battery cells. Make sure they're all tightly closed...

Just a word of caution here; you should never add acid to a battery unless it is brand new and dry.
Always use distilled water if possible.

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Archeo-peteriX

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Ferdinand

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Kelly
How does the battery acid and plate minerals escape from the battery's plastic case?

In your second photo, Battery Crud 2, look at the top surface of the battery that has the sticker saying "Danger/Poison". There are six round plugs with + shaped crosses on them. You can use a screwdriver to open or close those plugs to add acid to the battery cells. Make sure they're all tightly closed...

Just a word of caution here; you should never add acid to a battery unless it is brand new and dry.
Always use distilled water if possible.

Hi F and P,

Thanks! When the battery spits acid, how much volume is excaping? A few drops or 1/2 a cup?

Thanks, Kelly

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Kelly

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Archeo-peteriX

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Ferdinand

Quote
Kelly
How does the battery acid and plate minerals escape from the battery's plastic case?

In your second photo, Battery Crud 2, look at the top surface of the battery that has the sticker saying "Danger/Poison". There are six round plugs with + shaped crosses on them. You can use a screwdriver to open or close those plugs to add acid to the battery cells. Make sure they're all tightly closed...

Just a word of caution here; you should never add acid to a battery unless it is brand new and dry.
Always use distilled water if possible.

Hi F and P,

Thanks! When the battery spits acid, how much volume is excaping? A few drops or 1/2 a cup?

Thanks, Kelly

If everything is normal, it's like the drip at the end of your nose after eating chilis
Doesn't take a lot to produce big crust

If you check the fluid level in the battery and it is low, then you will have an indication of how much is being lost. It's best to check the levels often; once every couple of months when crust is evident; and top it up id needed. For a lot of older cars like ours; checking the battery is akin to checking the oil or the coolant levels

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Archeo-peteriX

If everything is normal, it's like the drip at the end of your nose after eating chilis
Doesn't take a lot to produce big crust

If you check the fluid level in the battery and it is low, then you will have an indication of how much is being lost. It's best to check the levels often; once every couple of months when crust is evident; and top it up id needed. For a lot of older cars like ours; checking the battery is akin to checking the oil or the coolant levels

Hi,

I visited my local auto-parts store in order to buy grease. They had cans which to me seemed rather large about the size of a mixed bridge nuts can. I asked the counter clerk if he had smaller packages. He handed me a packet (the size of a ketchup packet at a fast food eatery) of Battery protector grease which seemed sensible at the time. He also thought that I could use it for general purpose grease. When I read the instructions printed on the back, it read "Apply to battery terminals." Now i'm wondering if this is the "silver" grease which covers the terminals.Might not be a good idea to slather the battery tray with this? I have not opened the packets and could return them I suppose. They were not expensive.

Should I use this to coat the battery tray?

Pls let me know when you have a second.

:-) Kelly

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Kelly

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Archeo-peteriX

If everything is normal, it's like the drip at the end of your nose after eating chilis
Doesn't take a lot to produce big crust

If you check the fluid level in the battery and it is low, then you will have an indication of how much is being lost. It's best to check the levels often; once every couple of months when crust is evident; and top it up id needed. For a lot of older cars like ours; checking the battery is akin to checking the oil or the coolant levels

Hi,

I visited my local auto-parts store in order to buy grease. They had cans which to me seemed rather large about the size of a mixed bridge nuts can. I asked the counter clerk if he had smaller packages. He handed me a packet (the size of a ketchup packet at a fast food eatery) of Battery protector grease which seemed sensible at the time. He also thought that I could use it for general purpose grease. When I read the instructions printed on the back, it read "Apply to battery terminals." Now i'm wondering if this is the "silver" grease which covers the terminals.Might not be a good idea to slather the battery tray with this? I have not opened the packets and could return them I suppose. They were not expensive.

Should I use this to coat the battery tray?

Pls let me know when you have a second.

:-) Kelly

The main idea of the grease on the tray is to prevent the battery discharge liquid and gases from coming in contact with the metal.
The stuff made for the battery terminals is most likely a dielectric grease so may not be best for the tray.

Go to your nearest Jiffy Lube or similar and take a small plastic container. Be charming and I'll bet one of the guys would be happy to put a small bit of grease in it for you

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Archeo-peteriX
[
The main idea of the grease on the tray is to prevent the battery discharge liquid and gases from coming in contact with the metal.
The stuff made for the battery terminals is most likely a dielectric grease so may not be best for the tray.

Go to your nearest Jiffy Lube or similar and take a small plastic container. Be charming and I'll bet one of the guys would be happy to put a small bit of grease in it for you

Great idea! It will be extra impressive when I arrive on my white bicycle "the Flash" given that Beemie's battery is waiting on the basement floor. I just cleaned the bike, and it's looking extra white now.

Thanks! Kelly

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Ferdinand


Unfortunately as hydrogen is normally vented from the battery, it can also spit some acid from the vent. That 90-degree elbow really should have a rubber tube connected to the nozzle, routing any spilled acid down to drip safely onto the road and NOT onto any of the metal bodywork.

My 325 has the battery located in the trunk. The rubber tube from the battery vent leads down below the battery tray into a small plastic tank that collects any spilled acid before venting straight down through a rubber grommet set in the bottom of the rear fender. See #12 and #11 in this RealOEM drawing.

Hi Ferd and All,

Given this info above, I could tie-wrap a glass test tube to the side of the battery or somewhere nearby. Then run a small plastic tube from the battery vent into the top of the glass test tube. The hydrogen would naturally move upward out of the glass tube which would capture the acid which presumably would evaporate over time.

If I attach the glass tub to the battery's side, then the tube will be located somewhat under the positive battery terminal. Now, H2 near the + terminal might be bit iffy. On the other hand, the battery's existing vent tube is pointed in this direction. See Battery Crud 2 photo above if you like.

Thoughts anyone?

Cheers, Kelly



Edited 1 time(s). Last edit at 01/03/2010 10:08AM by Kelly.

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Kelly

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Ferdinand


Unfortunately as hydrogen is normally vented from the battery, it can also spit some acid from the vent. That 90-degree elbow really should have a rubber tube connected to the nozzle, routing any spilled acid down to drip safely onto the road and NOT onto any of the metal bodywork.

My 325 has the battery located in the trunk. The rubber tube from the battery vent leads down below the battery tray into a small plastic tank that collects any spilled acid before venting straight down through a rubber grommet set in the bottom of the rear fender. See #12 and #11 in this RealOEM drawing.

Hi Ferd and All,

Given this info above, I could tie-wrap a glass test tube to the side of the battery or somewhere nearby. Then run a small plastic tube from the battery vent into the top of the glass test tube. The hydrogen would naturally move upward out of the glass tube which would capture the acid which presumably would evaporate over time.

If I attach the glass tub to the battery's side, then the tube will be located somewhat under the positive battery terminal. Now, H2 near the + terminal might be bit iffy. On the other hand, the battery's existing vent tube is pointed in this direction. See Battery Crud 2 photo above if you like.

Thoughts anyone?

Cheers, Kelly

Kelly, You're thinking too much about this, route an overflow tube overboard and do some checks on the charging system just to see what you have. It takes a few minutes and a meter

Rick

Often a battery will seep acid out the top if the covers are not tightly installed or poorly designed. This acid will wet the outside of the battery and corrode everything metal it touches. what you may have noticed when you washed the battery if you used any baking soda in the wash was a bubbling of the wash water as the acid was being neutralized by the soda.

One word of warning too, do not leave soda on the battery tray once it is cleaned. Soda is corrosive to metal too. Rinse with plain water or soapy water to get all of it off.

One possibility is that the battery case is cracked. This would let the acid seep out and make a mess as well as cause the battery to fail with a dead cell.
The dielectric grease is great for the terminals and the hold down bolt to keep corrosion from getting to these important parts. It just keeps the acid from going there.

The most effective preventative to this corrosion is to wash the battery exterior with soda water occasionally taking care not to leave much on the top. Water on the top between the terminals when left there will allow the battery to discharge across the terminals through the dirty water. Rinse with clear water.

Bob in Everett

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Bob in Everett
Often a battery will seep acid out the top if the covers are not tightly installed or poorly designed. This acid will wet the outside of the battery and corrode everything metal it touches. what you may have noticed when you washed the battery if you used any baking soda in the wash was a bubbling of the wash water as the acid was being neutralized by the soda.

One word of warning too, do not leave soda on the battery tray once it is cleaned. Soda is corrosive to metal too. Rinse with plain water or soapy water to get all of it off.

One possibility is that the battery case is cracked. This would let the acid seep out and make a mess as well as cause the battery to fail with a dead cell.
The dielectric grease is great for the terminals and the hold down bolt to keep corrosion from getting to these important parts. It just keeps the acid from going there.

The most effective preventative to this corrosion is to wash the battery exterior with soda water occasionally taking care not to leave much on the top. Water on the top between the terminals when left there will allow the battery to discharge across the terminals through the dirty water. Rinse with clear water.

Bob in Everett

Hi Bob,

Thanks for the good advice. Sounds like I will need to remove the battery again next weekend and reclean the metal battery tray. I left a fair amount of baking soda paste on the battery case and the mat - not realizing that bicarb would damage the metal.

I used Valvoline Multi-purpose grease (a pinkish colored goo for GM and European cars) to coat the metal tray. I suppose I'll need to clean the tray again and regrease. What should I use to clean the tray now - Windex or 409 to cut through the Multi-purpose grease?

Thanks, Kelly



Edited 1 time(s). Last edit at 01/04/2010 11:41AM by Kelly.

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Kelly

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Bob in Everett
Often a battery will seep acid out the top if the covers are not tightly installed or poorly designed. This acid will wet the outside of the battery and corrode everything metal it touches. what you may have noticed when you washed the battery if you used any baking soda in the wash was a bubbling of the wash water as the acid was being neutralized by the soda.

One word of warning too, do not leave soda on the battery tray once it is cleaned. Soda is corrosive to metal too. Rinse with plain water or soapy water to get all of it off.

One possibility is that the battery case is cracked. This would let the acid seep out and make a mess as well as cause the battery to fail with a dead cell.
The dielectric grease is great for the terminals and the hold down bolt to keep corrosion from getting to these important parts. It just keeps the acid from going there.

The most effective preventative to this corrosion is to wash the battery exterior with soda water occasionally taking care not to leave much on the top. Water on the top between the terminals when left there will allow the battery to discharge across the terminals through the dirty water. Rinse with clear water.

Bob in Everett

Hi Bob,

Thanks for the good advice. Sounds like I will need to remove the battery again next weekend and reclean the metal battery tray. I left a fair amount of baking soda paste on the battery case and the mat - not realizing that bicarb would damage the metal.

I used Valvoline Multi-purpose grease (a pinkish colored goo for GM and European cars) to coat the metal tray. I suppose I'll need to clean the tray again and regrease. What should I use to clean the tray now - Windex or 409 to cut through the Multi-purpose grease?

Thanks, Kelly

Just a dry cloth to take the heavy stuff off and then a good cleaner (409 might work), but I use "super clean", its a great cleaner and cuts grease big time. WEAR GLOVES though... re-grease up the tray, and the hold down stud threads. Make sure the cable ends and the posts are good too (I know you know that but..

Rick

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rkj

Just a dry cloth to take the heavy stuff off and then a good cleaner (409 might work), but I use "super clean", its a great cleaner and cuts grease big time. WEAR GLOVES though... re-grease up the tray, and the hold down stud threads. Make sure the cable ends and the posts are good too (I know you know that but..

Rick

Hi All,

Well my initial grease application to the battery tray proved helpful. I could easily wipe off the baking soda flakes from the tray. I cleaned all the soda from the battery and the mat. Then I reinstalled the battery. Happily this was easier than I expected.

Here is an unrelated funny story - I have a long time Japanese designer friend of 15 yrs who lives in New York. She has a cousin who needed a furnished apartment for 6 weeks in Palo Alto CA about 35 miles south of San Francisco. The cousin had one apt lined up but it fell through a week before he arrived. I threw myself into finding a decent apartment for the cousin and his wife near the university campus. On Sunday, the airport shuttle dropped him at the apartment where the landlord and I were waiting for him. After signing all the lease paperwork, I took the cousin and his wife grocery shopping. I said "I'm sorry that I did not have a chance to wash my car. It's been raining on an off all week." He said in a charming yet heavy Japanese accent "Old school BMW. I like it. Convertible - very nice." I said "Yes, old school indeed." That's the Beemie - making friends as it rolls along. Even when dirty. Now I have friends in Kyoto.

Cheers, Kelly



Edited 1 time(s). Last edit at 01/11/2010 06:49PM by Kelly.

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Kelly

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rkj

Just a dry cloth to take the heavy stuff off and then a good cleaner (409 might work), but I use "super clean", its a great cleaner and cuts grease big time. WEAR GLOVES though... re-grease up the tray, and the hold down stud threads. Make sure the cable ends and the posts are good too (I know you know that but..

Rick

Hi All,

Well my initial grease application to the battery tray proved helpful. I could easily wipe off the baking soda flakes from the tray. I cleaned all the soda from the battery and the mat. Then I reinstalled the battery. Happily this was easier than I expected.

Here is an unrelated funny story - I have a long time Japanese designer friend of 15 yrs who lives in New York. She has a cousin who needed a furnished apartment for 6 weeks in Palo Alto CA about 35 miles south of San Francisco. The cousin had one apt lined up but it fell through a week before he arrived. I threw myself into finding a decent apartment for the cousin and his wife near the university campus. On Sunday, the airport shuttle dropped him at the apartment where the landlord and I were waiting for him. After signing all the lease paperwork, I took the cousin and his wife grocery shopping. I said "I'm sorry that I did not have a chance to wash my car. It's been raining on an off all week." He said in a charming yet heavy Japanese accent "Old school BMW. I like it. Convertible - very nice." I said "Yes, old school indeed." That's the Beemie - making friends as it rolls along. Even when dirty. Now I have friends in Kyoto.

Cheers, Kelly

Nice Kelly, old school it really is not but it's one of the nicest made

Kelly,
Hope your battery tray is staying clean and dry these days. One thing I do every few months is to take my cabrio to the the car wash and give the engine compartment a bath, including the battery. I do not spray too close to electrical connectors but give them and the battery a good going over from about a foot away. This keeps dirt from accumulating and giving acid a place to seep into. This also keeps hoses free of oil and dirt that rot them. Makes working in the engine compartment a lot more pleasant.

I have often wondered why our fantastic German engineering did not apply itself to keeping the engine oil inside the engine.

Bob in Everett