I bought a small 10kva diesel generator set about twenty years ago , just in case the lights went out as we live down the end of a long lane .

As it happens I have only ever used it three or four times

It’s key start , so if I want to use it I will need a new battery. However just leaving it hanging around will do the new battery no good whatsoever .\
I’m thinking of getting the battery and just not connecting it to the genset until needed.

So….. how do I look after the battery in between? Filters are in fact so good that in certain circumstances, when the ambient air is already polluted, a diesel car will tend to extract more particles from the air than it emits. Emissions Analytics worked with........etc etc

He who dies with the most toys wins...

How about using a small suitcase solar charger

We've got a big standby generator here. It's a 24v set up and needs 2 x 12v batteries to get it going.

The batteries on ours have been on it for years now, they are permanently connected to a conditioner/charger and have never given us any issues on the rare occasions that we've needed it to start. I'd go as far as saying that the batteries must be getting on for 15 years old now, maybe slightly more as it was around 2007 the generator went in.

 2002 4.6 Vogue SE - Alveston Red with Lightstone Leather
2012 Range Rover 5.0 SC Autobiography in Indus Silver with Jet/Ivory Interior
2012 Range Rover 4.4 TDV8 Autobiography in Baltic Blue with Sand Interior
2013 Range Rover Sport SDV6 HSE Black Edition in Santorini Black with Ebony Interior

Thanks very much. Bardley. DH & waylander. Filters are in fact so good that in certain circumstances, when the ambient air is already polluted, a diesel car will tend to extract more particles from the air than it emits. Emissions Analytics worked with........etc etc

He who dies with the most toys wins...