Mysterious 20amp fuse blow (near passenger side battery)

[g8dhe]

If you measure the current when "off" you will probably find around 50mA to 100mA with things on standby, like remote key fob receiver, radio backup etc. Any more than that then I dig down to find out what it is as like to understand where the power is being used

[BongoBongo123]

Sounds sensible no remote keyfob on mine.

[Dodgey]

I have seen fridges kill leisure batteries. Even though they have low voltage protection, switching off when the battery is below 10.8volts, they keep trying to fire up every 30 seconds or so, fail, then repeat.

This eventually drags the battery down very low.

Sounds like you'd benefit from a solar panel and the regulator it somes with You'll never have a flat battery again.

[BongoBongo123]

Super quick delivery on that battery. I put new battery on awaiting new fuses to turn up. So far so good with the new one. Put old battery on for charge thinking it would be an ok spare and it takes current at 1A . Now as I recall good batteries take 4-5A when they are flat so I am fairly sure this battery has reached the end of it's life now. 1A seems very low like some cells are no longer taking capacity.

[g8dhe]

Didn't the battery test out at about 2v ? If so it was dead and will never be revived! At a guess most of the cells are damaged well beyond any sort of use.

[BongoBongo123]

It did but I have no idea of what a "normally" flat battery reads at volts wise so thought it might be possible to revive, obviously not.

[Bob]

This may help:

http://www.aa1car.com/library/2003/us20310.htm

Also:

http://carbatteryonline.net/car-battery-tester.html

[g8dhe]

The normal minimum is 11.8 volts, the absolute minimum is 10.8 volts but even by then the cells are starting to be damaged, less than that and the chemical reaction changes and can't be retrieved back to normal at all.

[BongoBongo123]

Thanks for confirming, new battery was the right decision, must be very vigilant with the fridge off knob.