Warm leisure battery

Calahonda52

Two leisure batteries fitted in a camper van: Van plugged into mains, one is quite warm to the touch, the other, recently added, is stone cold.

1: Any thought on on the battery heating?.

2: how can the state of the second battery be tested, The panel will only show one value for that circuit

Thanks

db

that battery is starting to cook. take it out immediately.

Calahonda52

https://www.boards.ie/discussion/comment/120780839#Comment_120780839

Thanks, what life span would you expect from a leisure battery or was it deep cycled beyond what it should have been?

If let discharge completely a few to many times it can bring a battery life down to two seasons or less. Careful management and overspec'ing your battery might get you 5. Deep cycle batteries are said to be designed for deep discharge - but it still damages them by the same mechanism that a starter battery is destoyed - Leisure batteries cope better but are not immune.

A complete battery disconnect switch is advisable for any period left unused of more than a week - especially in the winter.

Calahonda52

Mission update, put the IR camera on it so when it read 91 Centigrade decided it was time to remove it.

Left it on the grass: OH not impressed with the scorch mark

Any thoughts on a replacement: LiPO perhaps?

LifPo are a good long term investment but very pricey. They don't need to be as big since they can be deep discharged better than lead acid and so need only half the capacity to do the same job. 10 year service life to boot.

Calahonda52

https://www.boards.ie/discussion/comment/120785877#Comment_120785877

Thanks, do I need a different charger than for the Lead acid?

https://www.boards.ie/discussion/comment/120785984#Comment_120785984

Yes but not certain what it involves. It has a different charge profile since unlike Lead Acid it maintains a steady voltage till it is almost empty.

LiFPo4 batteries need a Battery Management System (BMS) attached to the cells to control charging, if you buy a ready made battery you need to ensure that it has a temperature sensor built into the BMS since charging a LiFPo4 battery below freezing will damage it. If you build your own battery from Prismatic Cells (not difficult) then the BMS will need to have a temp sensor (most of the Chinese one do not). You can use a LiFPo4 battery below zero - so the more expensive batteries often have built in self heaters. Batteries mounted inside a van shouldnt have to many temp issues - but if you intend to use a solar panel to top them up this could be an issue you need to take into account.