12V battery replacement

[Maxx]

$160 for a 12v 50ah LFP battery (will it fit?), been using one in my work van to run a compressor, 4 of them power my riding lawnmower that were switched from AGM. Brought the machine to life compared but that's another story. Then I have a boat load more I run my house with when needed, that's a 51.2v system. All LFP batteries have an internal BMS.

Also have a Li battery in my motorcycle since 2012 and still cranks the bike like new. If I can make it fit, I'm pretty sure it will, I'm replacing with the 50ah and never worry about it again, they carry a 10 year warranty.

If you do use it and nothing blows up, let us know what exactly you used.

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[RLXXI]

If you do use it and nothing blows up, let us know what exactly you used.

Not worried one bit, they don't explode like traditional li batteries can and have in the past. I keep 43kWh worth in my attached garage I power my home with when needed. Here's the current battery I will use when the time comes, and it will, unless they come out with something even better. I know batteries all too well. Nothing special about Absorbed Glass Mat batteries, it's still a lead acid battery with those mats between the plates, that's it.

The LFP batteries don't care if you run them flat and you can't over charge them due to the built in BMS. My only concern is space, I haven't poked around in the battery cavity to see if it will or not. There are other brand LFP batteries made likely using the same exact brand of cell and in different size configurations.

 

[Maxx]

Not worried one bit, they don't explode like traditional li batteries can and have in the past. I keep 43kWh worth in my attached garage I power my home with when needed. Here's the current battery I will use when the time comes, and it will, unless they come out with something even better. I know batteries all too well. Nothing special about Absorbed Glass Mat batteries, it's still a lead acid battery with those mats between the plates, that's it.

The LFP batteries don't care if you run them flat and you can't over charge them due to the built in BMS. My only concern is space, I haven't poked around in the battery cavity to see if it will or not. There are other brand LFP batteries made likely using the same exact brand of cell and in different size configurations.

I didn't mean the battery physically blowing up. I meant Lightning BMS getting confused about when to charge the battery, how often and at what voltage.

Frankly I am surprised Ford didn't at least have the option for Li-Ion since they built the Lightning after Tesla had already switched to Li-Ion 12V. 98 KWh of of Li-Ion in it's belly and cheeping out on a small important one up front makes no sense.

Thanks for sharing the details. Let us know if you find out anything new about how Lightning talks to this battery vs the old one.

 

[El Duderino]

Some context might help provide color to this conversation.

Looking at individual cells nominal and 12v cells in series voltages can help explain how different or similar a lead acid, lithium iron phosphate, and lithium ion batteries are.

Nominal cell voltages:

Lead acid = 2.1 v
Lfp = 3.2 v
Lithium ion = 3.6 v

Nominal voltages of cells in series to fit a 12 volt battery application:

Lead acid (6) cells = 12.6 v
Lfp (4) cells = 12.8 v
Li (4) cells = 14.4 v

So lithium ion is quite a bit different than lead acid. But Lfp is pretty close to lead acid when comparing the whole battery voltage in series.

Without getting into the specifics of Ford's lead acid charging algorithm, you can at least see how a 12v Lfp battery charged with a 12v Lead acid charging setup would be close enough to not necessitate changes to charging voltages.

This post isn't the whole enchilada per se, but I am trying to illustrate that lithium iron phosphate 12v batteries aren't radically different than your standard lead acid 12v battery we have all known forever. The guts are different, cell balancing is more important in Lfp, but 12.6v vs 12.8v nominal is only 1.6% difference in amount...

 

[Maquis]

Interesting. I haven’t seen a cutaway. Thanks.
I think then I’ll stick to replacing my AGMs every few years.

Basically run of the mill cells and a circuit board held in place with spray foam.

 

[Robert1380]

Basically run of the mill cells and a circuit board held in place with spray foam.

So those Ohhmu batteries aren’t any good?

 

[SpaceEVDriver]

Basically run of the mill cells and a circuit board held in place with spray foam.

No hard mount on that circuit board!? It would jar loose in the first week of owning it with my road and the use I put my truck through. Nothing to stop the circuit board from contacting the terminals.

You couldn’t pay me to put that in my truck.

 

[RLXXI]

Basically run of the mill cells and a circuit board held in place with spray foam.

Damn that's some shoddy construction right there.

 

[johnnyonetime]

No hard mount on that circuit board!? It would jar loose in the first week of owning it with my road and the use I put my truck through. Nothing to stop the circuit board from contacting the terminals.

You couldn’t pay me to put that in my truck.

Not worried at all, 50k miles and 2 years later it still works every time I push the button!

 

[SpaceEVDriver]

Not worried at all, 50k miles and 2 years later it still works every time I push the button!

I am truly happy for you that it hasn't caused any problems for you.

I'll still keep using the AGM until there's a better solution that I trust.

 

[Maxx]

Some context might help provide color to this conversation.

Looking at individual cells nominal and 12v cells in series voltages can help explain how different or similar a lead acid, lithium iron phosphate, and lithium ion batteries are.

Nominal cell voltages:

Lead acid = 2.1 v
Lfp = 3.2 v
Lithium ion = 3.6 v

Nominal voltages of cells in series to fit a 12 volt battery application:

Lead acid (6) cells = 12.6 v
Lfp (4) cells = 12.8 v
Li (4) cells = 14.4 v

So lithium ion is quite a bit different than lead acid. But Lfp is pretty close to lead acid when comparing the whole battery voltage in series.

Without getting into the specifics of Ford's lead acid charging algorithm, you can at least see how a 12v Lfp battery charged with a 12v Lead acid charging setup would be close enough to not necessitate changes to charging voltages.

This post isn't the whole enchilada per se, but I am trying to illustrate that lithium iron phosphate 12v batteries aren't radically different than your standard lead acid 12v battery we have all known forever. The guts are different, cell balancing is more important in Lfp, but 12.6v vs 12.8v nominal is only 1.6% difference in amount...

‘Thanks for a very informative post. It would be nice if @johnnyonetime could measure the voltage at battery terminal with negative before and after BMS. When the truck has been off for a while and when it is on and share the results so we can compare with our original batteries connected.

No hard mount on that circuit board!?

In the company video, internals don’t look that bad. The board seems to be screwed in. Not sure if this is a newer version or a different model. With all the Chinese (I assume) written on the cover, it may even get more expensive than $500. Their Sodium batteries are $100 less expensive.

Min: 6:58

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