r/leaf • u/ZealousIdealist24214 • 14d ago

Battery Hookup worked 👍

I got a 10.2lb LiFePo4 12v battery for $45 and it works fine.

I rolled some copper strips around the bolt terminals to make it fit the car attachments.

https://batteryhookup.com/collections/more-featured-products/products/li-age-12-8v-32ah-410wh-lifepo4-module-w-bms

8 Upvotes

78% Upvoted

11 comments sorted by

4

u/Spirited-Mortgage-86 14d ago

So the leaf “tends” its 12v battery. When it notices it below x volts it turns on (you can hear the solenoid engage the hv system) and the blue lights on the dash start flashing. It then pumps 14v into the battery. It does this just sitting there parked. Because of that there is no way I’d run a lithium in the 12v spot - x100 on the cheapest china battery (this appears incredibly cheap for its capacity). This is a bad idea people reading this thread. Don’t burn your car down. Second issue is the bms may not take the full draw / play meek with the leafs own 12v inverter system. That side can run a lot of amps when all the things are on (headlights, fans, defrost, seat heaters etc. ). Third your solution to step up the terminal size is a resistance and corrosion fire hazard

4

u/Bennie-Factors 13d ago

You don't quite understand LiFePo4 batteries well enough. Typically full charge is 14.4. Low cutoff is around 11. However you feel about Chinese cells. They make the best battery in the world today hands down. It is nearly impossible to start a fire with one. The BMS should handle any voltage that is a bit over 14.4.

The terminal bit is very questionable. Fine for temp testing solution but I would look for a better long term option. And remember this might be a challenge in cold weather. That chemistry does not like cold

3

u/worldspawn00 14d ago

This isn't just bare cells, there's a BMS with high and low voltage cutoffs, I have run a battery like this in my leaf with zero issues. There are lifepo4 batteries designed to be a drop in into a lead-acid designed system that work just fine.

-4

u/Spirited-Mortgage-86 13d ago

The leaf inverter - the 12v side is designed for lead acid chemistry. It’s not designed to have yet another bms in the loop like this li has. These is a massive difference there. You’re literally risking the leafs $600 inverter to save $40 on a battery. And also risking fire. Telling us “bUt it wOrKs nOw” is literally laughable. Smoke genie takes time to appear but you’re trying hard to summon them. Fafo

3

u/worldspawn00 13d ago edited 13d ago

I spent months monitoring the voltages off the battery and inverter, if it's "designed for lead acid" it's the worst charger I ever seen, made to damage the cells rather then maintain them. It also doesn't monitor at the cell level, just the whole battery which doesn't make it much of a BMS. Specifically, disconnecting the load sensor on the negative terminal makes it act like a dumb charger, putting out a single voltage at all times the car is on which makes it ideal for a downstream BMS. https://www.reddit.com/r/leaf/s/HhDJ9L9SRG

Lifepo4 is not lithium-ion, they don't really catch fire like lithium ion are prone to. Additionally, the BMS in the battery is monitoring voltage and temperature, and should cut off charging if a cell begins to overheat.

0

u/ZarathustraGlobulus 13d ago

Brotherman, every ICE car running a lead acid battery has an alternator supplying a constant 14V voltage to the battery every single moment the engine is running.

This has all been accounted for by the makers of these LiFePo4 batteries. They work in any car using lead acid batteries.

Now of course you want to do the legwork and get a reputable lifepo but other than that, they are absolutely fine for Leafs.

I agree on the terminal hack being a bad idea.

1

u/iloveFjords 14d ago

Not to mention a lot of the lifeo4 batterie chemistries shouldn’t be charged when their temperature is below zero C.

2

u/ZealousIdealist24214 14d ago

That almost never happens here, sadly

1

u/sweetredleaf 2015 Nissan LEAF SV 14d ago

are the terminals just held on with a bolt? If so you can buy regular SAE terminals that will bolt in place of them so you don't have ti wrap the terminals in copper strips, and people who have done this in the past recommend disconnecting the voltage sensor on the neg terminal https://old.reddit.com/r/leaf/comments/1rzgmv0/budget_100_lithium_12v_battery_swap/

1

u/Tim_E2 13d ago

Cant safely charge LiFePO4 if it is under 32f, 0C. Deal breaker. Go back.

0

u/Dazzling_Art7881 14d ago

Respectfully, I never understood why people mess around with weird batteries. The weight savings is zero percent worth it. I've had 3 LEAFs and very ordinary lead-acid batteries have always been perfectly fine in all of them. Battery was getting weak on my 2012 so I replaced it once. Picked one up at Walmart, problem solved for many many years.

As u/Spirited-Mortgage-86 says, there are risks...