Tacoma battery upgrade to Lithium?

OEM do put Lithium batteries in new cars. Hybrids, Plug-ins, EVs, etc.

If you are talking about 12v versions, then a couple Euro performance car models have had them for years now. They can cost a fortune for an OEM replacement.

 

Lithium batteries need to be totally run down before they can be recharged they have memory, or you will destroy their ability to recharge fully eventually making them worthless. I doubt these trucks have that ability to know when. Lead acid batteries are different.

 

Forget this post...i was mixed up thinking of a niCAD battery.

 

I built and put a lifepo4 under the back seat. When truck is off, it's in parallel with the starting battery so the capacity of both is used. When truck is on, the lifepo4 is isolated and charged separately via a boost converter set to 14.4 volts. So the lifepo4 gets constant volts and constant current. I also integrated a temp sensor so if temp is below freezing, it uses the charging current to heat the battery first. Once above freezing, it starts charging.

I figure it will last longer than the truck.

You don't need a 500$ battery and a 200$ charge controller. Just $50 in parts for boost converter and relays, then build your own battery pack of any size.

Under hood volts,. Back seat volts.

 

That is cool. I like the dual volt meter. I have one for each branch, but the rear one is well hard to see unless I’m in he back seat. Typically when I’m in the backseat it is somewhat electrified so I forget to look at the meter.

 

LiFePO4 batteries are kinda weird on voltage. They dont have a linear voltage drop like lead acids do.

On a lead acid (at rest, no active draw), you know that 13V is topped off, 11.5V is in the danger zone, and 12.3 is somewhere in between.

From personal experience the topped off state (100%) of a Li-Iron is at 14.3 - 14.5 V, then they want to immediately drop to 13.5 or thereabouts and sit there for the vast majority of their discharge. Once you drop below 13.0-12.9 V you have maybe 10% battery left before it completely flats out at <11 volts. The huge horizontal line in their voltage curve makes it difficult to guess their state on just a voltmeter.




If you are putting a heavy cycle on lithium iron, I would recommend using a coulombmeter (amp-meter) to measure its state. Its slightly more accurate.


This little knock-off monitor is cheap and as functional as the 200 dollar version. I run the rectangular shaped version in my camper - it very closely agrees with my multimeter.

$39 AiLi Battery Monitor Voltmeter Ammeter Voltage Current Meter 8-80V 0-100A Auto Car Motor Boat Caravan RV Motorhome

https://www.amazon.com/AiLi-Voltmeter-Ammeter-Voltage-Motorhome/dp/B07CTKYFTG?th=1

 

Correct on all points and I have a similar amp meter already on other lifepo4 batteries I've built.

One can sorta gauge the fullness of lifepo4 using those two volt numbers. Mine's set to charge at 14v, so bottom gauge will peak at 14v. Once near full, amps start to drop and the top volt number(vehicle volts) goes up, because of less load.. At which point lifepo4 is around 95% charged. If lifepo4 is 12v or less with no load, it's 95% dead. Most of lifepo4's energy is in the 3.0 to 3.5v range per cell.

 

That's really cool!! You should consider doing a thread on how you did it or making a kit to sell

 

my 2015 BMW M3 has a li-ion battery as OEM.

 

REALLY interested in how you did your setup!

 

A lithium fire can be extinguished with a class ABC fire extinguisher.
https://firefighterinsider.com/the-best-fire-extinguisher-for-lithium-ion-batteries/