FePo4 no not rust converter

[caprinut]

Is there a LiFePo4 battery out there to replace standard car battery yet?

Bert

 

[PhillipM]

Plenty, they've been around for a decade or more, expensive though, expect to be paying ~£500 for anything with decent enough Ah to stand up to daily driving and winter accessory drain.

 

[500e]

That's no expensive though

 

[Kram]

Be aware that a LiFePo4 replacement only needs about 1/4 or 1/3 the Ah compared to a lead acid, and that is generally what you get for the price difference too. Not a big problem as Pb are oversized for degredation and never give half their real capacity

The voltage regulation in most doesnt line up exactly with the 2.8/3.6v per cell limits. Almost suits a 4 series pack but not quite.
Ideal you'd find a new car that has a good system factory fitted and pinch the regulator/balance charging system from one of those to retro fit.

 

[caprinut]

Some appear to use super-capacitors to get the starting current from a smaller capacity battery pack.

T would expect a circuit with something like super capacitors for cold starting current they have a problem with chucking out such a high amperage.
I want to leave the battery in the engine compartment with an engine change a lead acid battery won't fit, also they last significantly longer and weigh less off setting the high price.

Bert