In article o.uk, Dave
Liquorice scribeth thus
Power cut this afternoon about 1700, text from DNO saying High
Voltage fault off until 2030. Drag out generator, battery utterly
flat. Pull started the (diesel) generator and power came back about
1900. Even after that couple of hours the battery didn't have enough
umph to engage with the starter ring. It sits at about 11.5 V, one
end cell looks a bit low one electrolyte and the case at that end is
slighly bulging. Battery is kept on genset in the unheated garage so
may well have got frozen. Perhaps not last winter but in 9/10 or
10/11 it got below -10 C without much trouble.

Time to change it. A good battery should be able to turn the engine over
after a couple of hours of charge.

How do car batteries get on in cold countries being outside all the
time;-?.

Pretty sure the battery is a gonner and I'd not trust it anyway for a
semi-critical system. It'll be replaced but how to keep the new one
in good condition for years with it doing basically nothing. The
genset might called into service in anger once a year and
occasionally if it's "a while" since the last in anger run I'll fire
it up for a couple hours powering a fan heater to make sure it still
works.

So how do you molly codle a lead acid battery that doesn't get much
use? Keep it somewhere a bit warmer? Would have to have an easy to
use plug/socket capable of carrying the starter current. I don't want
to be fiddling about reconnecting the battery in the middle of the
night, by torch light, whilst being battered by a gale and driving
snow...


Any other suggestions?


We have a genset thats almost under the same conditions, thats to say
lives outside in a sort of outhouse. We float charge the battery with a
13.8 volt power supply that IIRC delivers around 5 amps at most made
with a LT-1083 voltage regulator.

Works fine and has done so for around 4 to 5 years now since fitted.
We now and again just fire the genset up to see if it works and it does,
but it might be months between those events but the battery has never
failed to deliver and that must be some 8 years old or thereabouts
now....

FWIW..

We made up a very effective auto-start and changeover system using these
modules which aren't that expensive and do work well having been used in
anger around three times in as many months with a duff overhead
supply!..

http://www.gencontrol.co.uk/
--
Tony Sayer