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12 Volt Lead Acid Battery Replacement

Posted: Mon Jul 18, 2011 7:20 pm
by coolfilmaker
I just learned of the horrifying fact that leafs come with lead acid batteries. Does anyone know of an appropriate replacement? I have read of lithium ion replacement batteries for ICE but I'm wondering if anyone knows of one that works well. The thought of reducing my range even one tenth of a mile with a lead weight is nauseating. Thanks

Re: 12 Volt Lead Acid Battery Replacement

Posted: Mon Jul 18, 2011 8:04 pm
by Herm
Get yourself a 4 cell LiFePO4 pack, it will outlive you and me together. 30Ah should be plenty.

Re: 12 Volt Lead Acid Battery Replacement

Posted: Mon Jul 18, 2011 8:15 pm
by coolfilmaker
That's what I was thinking. Any specific recommendations on where to get one?

Re: 12 Volt Lead Acid Battery Replacement

Posted: Mon Jul 18, 2011 8:21 pm
by EVDRIVER
Be sure that you are in compliance with any LEAF sensors like the battery terminal temp sensor and any 12V monitoring, etc. The LEAF has more checks on the battery then a normal car, it's a bit ironic.

Re: 12 Volt Lead Acid Battery Replacement

Posted: Mon Jul 18, 2011 8:29 pm
by TonyWilliams
Herm wrote:Get yourself a 4 cell LiFePO4 pack, it will outlive you and me together. 30Ah should be plenty.



And you can put it anywhere !!!

Re: 12 Volt Lead Acid Battery Replacement

Posted: Sat Jul 23, 2011 6:53 pm
by RickS
I am running a 40Ah GBS LFMP pack in my Prius for the aux battery:

http://elitepowersolutions.com/products ... ucts_id=90

It serves a similar purpose, basically boot up the car, act as a 12 volt reservoir, power accessories when the car is in accessory mode and act as an emergency brake booster power supply.

The OEM lead 12 volt has strange 2/3 size automotive posts so you just about have to go get a replacement from Toyota which is in the $150 range on the low end. I ended up not spending too much more for the lithium pack. I am running individual cell balancers for an added level of safety and longevity. The car under charges the pack slightly giving it about 3.5 volts per cell (3.6 is the target charge voltage). The under charge should extend the battery life actually. It's been in there for six months now and is working well. I plan to pull it at about a year and run a capacity test on it to see how it's really holding up.

The only down side is there is no forgiveness for over discharging. If you were to leave an interior light on and it drains the battery to 0 volts the battery is dead, it does not come back. A typical application in an EV has a battery management system which has interlocks to prevent over discharging or over charging.

When the lead battery dies in my Leaf it's being replaced with lithium as well.

*Disclaimer* I work at Elite Power Solutions

Re: 12 Volt Lead Acid Battery Replacement

Posted: Sat Jul 23, 2011 11:43 pm
by Volusiano
If the charging system on the Leaf for the 12V battery (not to be confused with the 3.3Kw charger for the main battery pack) is designed to charge Lead Acid batteries, you can't just swap in a different chemistry type battery and expect that the current charging system is compatible with the new battery type, can you?

That 12V lead-acid battery in the Leaf looks pretty small so it can't be heavy enough to really have an effect on the Leaf's mileage.

What is the price difference between replacing the 12V lead-acid battery with a different type battery anyway? Is it really worth it?

Re: 12 Volt Lead Acid Battery Replacement

Posted: Sat Jul 23, 2011 11:48 pm
by TonyWilliams
Volusiano wrote:
That 12V lead-acid battery in the Leaf looks pretty small so it can't be heavy enough to really have an effect on the Leaf's mileage.

What is the price difference between replacing the 12V lead-acid battery with a different type battery anyway? Is it really worth it?



It doesn't appear to be "worth it" to you. Some of us, myself included, don't want to have 1850's technology lead and acid in their 21st century car.

Re: 12 Volt Lead Acid Battery Replacement

Posted: Sun Jul 24, 2011 5:53 am
by Nekota
TonyWilliams wrote:
Volusiano wrote:
That 12V lead-acid battery in the Leaf looks pretty small so it can't be heavy enough to really have an effect on the Leaf's mileage.

What is the price difference between replacing the 12V lead-acid battery with a different type battery anyway? Is it really worth it?



It doesn't appear to be "worth it" to you. Some of us, myself included, don't want to have 1850's technology lead and acid in their 21st century car.


Hmmm - speaking of old technology those round wheels are pretty ancient technology.. ;)
I'm still keenly awaiting those foldup ones on that modified DeLoren with Mr. Fusion energy pack 8-)

On a more serious point, the charging technology used is important and dropping in a LiCo chemistry battery pack to replace the lead acid could be dangerous. I learned that NiCd batteries explode when charged with constant current compared to flooded lead acid when I was about 10 years old. I was blind for about 2 days after the second NiCd cell exploded as I was disconnecting the charger from the remaining cells in the pack.

Re: 12 Volt Lead Acid Battery Replacement

Posted: Sun Jul 24, 2011 7:43 am
by smkettner
TonyWilliams wrote:It doesn't appear to be "worth it" to you. Some of us, myself included, don't want to have 1850's technology lead and acid in their 21st century car.

Is your battery contructed with a wood box and sealed with tar? Or do you have six glass jars connected in series?

You might consider a modern AGM battery. (still lead/acid)

BTW, does anyone know the group size of the tiny battery? Or what does the little thing actually weigh?