What's the biggest battery you can fit in a Gen.4?

Leaving the headlamps on overnight will kill a battery. Re-charging it is pointless.

Roger

wrote:

Leaving the headlamps on overnight will kill a battery. Re-charging it is pointless.

Roger

I have left enough stereos running and lights on and such often to the same battery repeatedly and never once have I had a direct result be a written off battery. I'm not saying it's something you should aim to do frequently but it won't automatically write a battery off unless there's something else going on like the alternator providing unregulated voltage or something else serious.

A battery is considered dead when the voltage drops to 11.7. Just what would you consider is necessary to achieve this figure?

Roger

wrote:

A battery is considered dead when the voltage drops to 11.7. Just what would you consider is necessary to achieve this figure?

Roger

A battery at 11.7v might be flat but it will easily recharge on even a basic charger.  Below 10v it will probably recharge but might have some loss of capacity and might need several reconditioning cycles.  Lead Acid batteries don’t fail all because the voltage gets low, they have to be in that state for an extended period or have to suffer another problem, too many charge/discharge cycles, massive over-voltage, large discharge currents, ripple when charging, vibration, a build up of sulphates, etc.

I have fitted a Yuasa HSB 053 battery to replace the standard unit. I look on this upgrade as just that, extra capacity as and when or even if it is necessary in the future. My thanks to all those who offered advice.

Roger

My Jimny 2021 is eating battery like crazy when locked. I guess it's because of the alarm system. The battery went completely flat (to a few V) 2-3 times. Now it lasts only 24h. I'm trying to save it by using Noco GENIUS5 repair mode several times (2x4h didn't help much).

I'm looking into AGM batteries due to deep discharge possibility so I wouldn't have to worry so much. Unfortunately the only AGM I've found that fits is Optima YellowTop YT R 2.7J 38Ah (Model no. 8072-176 / EAN 4016987113622):
uk.optimabatteries.com/en-gb/products/yellowtop/detail/yt-r-27/

I wish there were some good quality cut-off systems:
priuschat.com/threads/12v-battery-low-vo...o-disconnect.132609/
or Lithium batteries with BMS available.