Overwintering 85AH spare battery

Fully charged. And bring it indoors if possible and keep in a dry cool place. No need to discharge or keep charging - if it's a good battery it will be fine after the winter.

I have not had problems overwintering a disconnected 70AH car battery with temperatures down to -40F. Did this for a 10 year period.

Assuming it's a lead-acid battery, it should be stored fully charged. I would charge it as normal then put it on charge for an hour or two once a month at least. On these occasions it should start off taking a few amps but very soon drop down to a very low charge rate.

I'd be inclined to keep it indoors, somewhere without much temperature fluctuation. I have no evidence for saying that however, but I still would.

My own deep discharge batteries are permanently connected to 'intelligent' chargers that trickle something like 10mA into them all the time. This seems to work and the batteries last about eight seasons.

Bill

Provided that it's got (& keeps) a decent level of charge in it.

The electrolyte in a flat battery will freeze at (roughly) -8C.

A 70% charge will keep it liquid down to (roughly) -35C.

Thanks Bill, Phil, Dave, Capitol and Sam for the tips. I'm mighty relieved that I don't have to fully discharge it.

Find you local Lidl and see if they have any of the small intelligent battery chargers they were selling week before last left. If so get one, plug it in and leave on battery until you next need it.

I think it's worth checking up on these intelligent chargers. Some of them are not all that intelligent. I have one that says it is suitable for every sort and size of lead-acid battery. However the no-load voltage never drops below 19.3V and the charge rate never drops below

Bill

Leaving it in a discharged state would actually damage it, hence everyone correctly say leave it in a fully charged state.

as folk said, keep it well charged. It'll be better outside than in in winter, reaction rates halve for every 10C drop. Keep it dry & out of the sun ideally.

NT

I was thinking that but at the same time wide temperature fluctuations might do more damage.

Something like a cellar would be best!

intelligent

Presumably not the one you have connected all the time and trickling

Still mulling over options to keep the genset battery charged. The small solar PV panel is favourite and I've realised that if on the east facing side it will get full sun for maybe an hour at dawn, even on mid winters day, mid summer will be 5 hours plus. Trouble is the panel isn't weather proof...

I'd be more worried a cheap solar panel type wouldn't overcharge the battery?

If it is capable of charging one it is probably capable of overcharging it too - if it doesn't have decent electronics.

'Any battery'? It certainly wouldn't do any harm to typical large boat leisure batteries which will have capacities typically in the 400 to 800AH sort of range.

That's not to say that the charger you're talking about isn't rubbish of course.

You will be pleased to know that both the Lidl and Aldi ones I tested did exactly what they claim.

I'm puzzled. Why would you want to know the torque of an outboard? It seems to be a common measurement, although some just report it as pounds.

At least nobody has spotted he is probably using it for trolling :)

Andy

Not likely with a panel that is only rated at 1.5 W. B-)

I don't have an intelligent one, just a basic 4amp trickle charger. Googled one of these :-

Bit pricey at £35 but I guess the battery would need a charge also say, mid winter?

An 'intelligent' charger would be cheaper at £28_

Recommended (3rd choice) here _

Jimmy

Sorry, forget Leisure Outlet for the Streetwize Intelligent charger, I've just seen their delivery charges !!

Better bet is Amazon Traders or this one on ebay for £30 inc p+p