Dual Battery Build with Lithium

[krbjmpr]

Just received (12) LEV60F lfp cells. 75Ah, max 600A output, 180A continuous.
Will be building LFP battery exclusive for start (8 cells, 4S2P) and another for chassis (4 cells). Big things, though. Going to make some mock cells to figure out packaging and placement for start battery at passenger side. Driver side will be piece of cake.
When starting, batteries seperate. Engine running, batteries connected. Found a Daly BMS that is happy with 300A - 500A output. Pricy BMS, looking for other sealed alternatives

Cells (In Hand):

Search: 1 result found for "Lev60f"

Battery Hookup

batteryhookup.com

BMS (To Order):

Amazon.com

Bought a pair of inductive gauges to give me peak start currents. Analog, and my particular set has 1 rated to 600A, other rated to 200A (for alternator). Just lays along cable in question, circa 1970s. My DC Clamp meter yields 180A draw on first start at around 40°F.

More posts as I make progress.

 

[j91z28d1]

there was a small 30$ bms guys were using for diy starting battery build. it was from those little jump packs they sell. it allowed a lot of current out, and limited in after the car started. they linked to it, but it's been a long time ago now. but might help your searching.

sealed and small

 

[krbjmpr]

I know which one you are talking about. Tried it myself, epic failure.

Did not pay attention to battery chemistry. That particular one was for 3.6 / 3.7v cells (IMR, NMC, IDK, POS, etc).

I was using LFP, 3.2v cells. All ruptured their seals and spewed whatever evilness it contained. LFP electrolyte is highly conductive. Burned 2awg long cables making into short 2awg cables.

 

[krbjmpr]

Finally got an assistant to help me measure starter current. Used a BluePoint inductive gauge (ol' skoolz here). 180 Amps with a still warm engine parked 20 minutes prior. That is the continuous current rating of a single cell, so 2 in parallel should be ablecto handle winter cold starts.

Hoping to post pics of cells and possible container (nfg Chinese Stop/Start H6 battery shell) tomorrow morning. Won't hold 8, but maybe 4.

Making mock cells is more involved than I anticipated. Thicker than 2x lumber. Frustration had me reaching for 4x4 post to send through planer many many times before sanity prevailed and went to work.

Mock cells first, don't want to risk my precious with inadvertent short circuit or drop to concrete.

Also going to finally get around to upgrading this vehicle with 1/0awg cable.
It's a terrible thing to work on daily driver but also working 2nd shift.

 

[kbuskill]

Finally got an assistant to help me measure starter current. Used a BluePoint inductive gauge (ol' skoolz here). 180 Amps with a still warm engine parked 20 minutes prior. That is the continuous current rating of a single cell, so 2 in parallel should be ablecto handle winter cold starts.

Hoping to post pics of cells and possible container (nfg Chinese Stop/Start H6 battery shell) tomorrow morning. Won't hold 8, but maybe 4.

Making mock cells is more involved than I anticipated. Thicker than 2x lumber. Frustration had me reaching for 4x4 post to send through planer many many times before sanity prevailed and went to work.

Mock cells first, don't want to risk my precious with inadvertent short circuit or drop to concrete.

Also going to finally get around to upgrading this vehicle with 1/0awg cable.
It's a terrible thing to work on daily driver but also working 2nd shift.

I like what you are doing here. I'm curious how the trucks "BMS" will interact, or interfere, with what you are doing. Do you plan on keeping the sensor that goes around the negative cable?

It would be cool if HP Tuners could just adjust the charging system to be compatible with LifePO4 batteries.

 

[krbjmpr]

Actually, I bought a pwm box that would allow me to set alternator output. Plan us to keep it at 13.8vdc. That yields (13.8 / 4) 3.45 cell voltage, compared to needlessly stressing cells at 3,65 (14.6v max charge).

Also good with the 13.8v output as most things automotive are rated at 13.8, and not the 14.5 / 14.9 / 15.2 vdc I have seen Torque report. Might even be why I am on my 4th OBD bt adapter.

And no, the current sensor will be removed, at least from cable if truck throws a warning about it.

 

[Trey Hardy]

I will say my buddy done a lithium swap in his Tahoe I don’t know what your trying to run but he did 12 cells I believe and he was pushing over 20,000 watts in it

 

[Trey Hardy]

I want to say he never put any under the hood he built a dummy battery which wired up to the yinlong cells in the trunk for starting