Peter Kelly wrote:Mike W.
In non-vehicular use ( I include aeroplanes as vehicles), you are 100% correct. Undercharging and sulphation is the main cause of death - especially leaving the battery at a low state of charge for long periods.
In vehicles and especially aeroplanes with ancient nasty voltage regulators, overcharging results in a quick death.
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@Peter Kelly
Our principal aircraft fitments were Hawk, BAe 146, F16 and Puma - we didn't tend to see charging problems with those!
We didn't do GA batteries but when I put one block of the 4 used in the Hawk (20Ah SLA) in my Jodel the problem was undercharge, the poor old Delco dynamo struggled to get over 13.8V. (The reg was OK.)
Old cars in some overseas locations did the same but modern vehicles either worked correctly or produced nothing.
I take your general point though. GA aircraft other than very recent have to run on old junk that would have been dumped from cars long ago, and if you get serious overvoltage from an alternator, it's a quick killer especially with SLA.