Converting the fleet to LiFePO4 batteries!

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Fred
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Converting the fleet to LiFePO4 batteries!

Post by Fred »

For a long time I've been wanting to get into Lithium Iron Phosphate batteries to replace my constantly-failing lead acid collection most of which is ready for recycling with 6 that are dubious but still working (940 wag, 740 sedan, 240 sedan, Lantis, big one for winch, small one for Carib). The rest of the fleet have been on jumper pack duty for some time:

240 GLE wagon
Stagea
360 hatchback
Suzuki Wagon R Wide
Hotel Hyundai
240 GLT wagon
KP60
Ute
BMW front cut

And finally, I did it, I found out about Headway 38120 HP 200A rated cells and how inexpensive they are, and ordered 8 to play with. Tested 4 on the Suzuki as commented below, and much success.

========== Original post minus original text moved back to Suzuki thread and supplemented: viewtopic.php?f=3&t=2530&p=44755#p44755

https://twitter.com/FredCookeNZ/status/ ... 1333916673

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https://twitter.com/FredCookeNZ/status/ ... 8855455745

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https://twitter.com/FredCookeNZ/status/ ... 4802856960

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Exciting times! Can't wait to get the solenoids and get them installed in some of the fleet, then order some more for the rest! :-)
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ToxicGumbo
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Re: Fred's 1998 Suzuki Wagon R Wide!

Post by ToxicGumbo »

That is freaking awesome. I sold the Ford I had intended to supercap and probably for the best given how much better this arrangement looks. Any chance of using solar trickle-chargers to keep them from bottoming out?
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Re: Fred's 1998 Suzuki Wagon R Wide!

Post by Fred »

Yeah, you could go that way, too. As long as there's something to keep them topped up be it total isolation (my intention) or constant-charging (your suggestion), you're good.

I'm planning to run them without a BMS for now, see how they go as is. Ned and Cam told me I should put an active BMS on there as they draw micro amps and won't hurt the longevity between car uses. I'll have to run the math, they are only 8AH capacity which isn't much.

I know from experience with my jump pack pictured above that it'll crank the hotel around in gear with a totally dead lead acid for a significant period of time before the alarm goes beeping, maybe about a minute. I'm more worried about starter overheating than killing the jump pack. It's also 8AH, same chemistry, but rectangular/flat cells (had it open the other day).

What I mean by that is, if the car is in good health it'd probably start fine with 1/4 capacity in the battery due to the voltage profile of them and low internal resistance.

Good point re caps, though, I should run something in parallel with them to absorb high frequency ignition voltages and prevent micro damage from brief high voltage spikes.

The cool thing is they're $17 each from https://evassemble.com/ and come with the plastic end caps to suit the number you buy. I got 8 + a 6A charger as pictured to pre-charge them.

Going to run a datalogged LeadAcid vs Headway38120HP4S test on the 240 sedan to gauge performance / capacity to start a moderately high compression 2.3l engine.

Stay tuned :-) Maybe I should fork this into a thread of its own in pit lane and link back to that from here. Might just do that. Maybe tonight.
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Fred
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Re: Converting the fleet to LiFePO4 batteries!

Post by Fred »

Split this off from Suzi thread and reworded the start of the first post. More testing shortly, hopefully! :-)
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Fred
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Re: Converting the fleet to LiFePO4 batteries!

Post by Fred »

Testing results: https://twitter.com/FredCookeNZ/status/ ... 9476634624

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In summary, 4S did work on the 2.3 10:1 Volvo 4 cyilnder, and more than only just, but too much voltage sag for my liking at initial cranking. Recovered nicely once rotating, but I felt too hard on the battery cells, starter, and tuner trying to cope with such wild variation.

IE, 4 cells better for the 2.3 litre fleet. And probably for the 2.5 litre RB25DE and the 2.0 4G63 and the 2.0 KF-ZE and the 2.0 B200F too, especially because that last one will be going 2.3l high comp anyway.

I will add some datalogs and/or screenies thereof later.
DIYEFI.org - where Open Source means Open Source, and Free means Freedom
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n00bs, do NOT PM or email tech questions! Use the forum!
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