Batteries

FERENZA

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Batteryoutage , drops from over 13 amps to 12 over night nothing is switched on . seems alot to me. any ideas ?
 
What technology is the battery? Where are you taking the voltage reading? How accurate is the meter? What is the system state at 13v?

So, for example, if the battery is lead/acid and you're taking the reading away from the battery (e.g. the motorhome system panel) and/or the meter reads low, there might be nothing wrong with the battery. This is almost certainly the case if the 13v is just after full charge (e.g. just after turning off the engine or disconnecting EHU).

A 12v lead/acid battery is nominally 2v per cell, or 12v for a 6-cell battery but this is 2.1v per cell for a healthy battery at full charge. Charging is often at over 13.8v and a residual 'over-voltage' persists for a little time after the charging stops. So if the actual voltage at the time your meter reads 13v is actually 13.6v, the meter would be reading 0.6v low and this should be added to all readings and thus the 12v measurement is actually 12.6v, which is the 'at rest, open-circuit' voltage of a fully charged, healthy lead/acid battery!
 
Wrong kind of wind Eric. Your wind turbine is sucking not blowing.🖕
 
I would say if there really was no or minimal load, with that kind of voltage drop (assuming voltmeter is reasonably accurate), the batteries are probably shagged.

This is the kind of voltage drop you could expect from a new 100Ah Lead Acid battery with a very small load over 20 hours.
1603658625594.png

This is the same timescale with a not that much different load for a Varta 75Ah Battery that is knackered (bear in mind different scales)
1603658544107.png
 
My engine charges at 14.4v and after switching of its sits at 13.7 but settles to 12.7 which is correct for a healthy battery, my solar panels always keep it up and even on dull short days im reading 12.6 to 13.7 sitting on my driveway with only voltage meters and a digital clock/temp meter running.
 

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