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Solar battery charger
number-1 - 16/9/22 at 03:58 PM

Can anyone recommend a solar panel battery charger for a garage with no power? I need something tried and tested to keep a car battery topped up as it won get used possibly until spring next year.

I will start and run the car a few times a month for half hour or so too

Access to remove the battery is a real PITA and a knuckle killer

Edit : It needs to be suitable to leave on a garage roof...

Any links would be great

Cheers

N1

[Edited on 16/9/22 by number-1]

adithorp - 16/9/22 at 09:47 PM

I looked into them earlier this year and theres loads available. Most control the max voltage but rely on night/day to prevent constant charging. In the end I bought an Optimate solar charger Partly because its a known make but also is a smarter in sensing battery condition and charging/maintaining accordingly. It can be connected up to whatever solar panel you choose.
It comes with a plug/lead that can be permanently connected to the battery and then plugged into the charger, so that'd save your knuckles

ianhurley20 - 17/9/22 at 08:11 AM

Not quite the same - but - I bought an offcut of solar panel 300 x 300mm with + and - connections from ebay. (Wood offcuts made a frame and glued onto roof of shed/ workshop). Also a solar charge regulator from Amazon which had two USB outputs , a small LCD display which gives current voltage (£8.50) and hooked the system to a small gel 12v 14amphour battery I had bought second hand several years ago. I use it to provide lighting (6 x 3 watt chinese drl LED lights £4.50) , charging for various USB based things (cycle lights, DAB radio, mobile phone etc). The system works very well for me and although not exactly waht you are after the principles still work. (One tip would be to disconnect the solar panel before disconnecting your battery as the components need the battery load to work). I've used this sort of system for 15 years on another shed which is still going.

CosKev3 - 17/9/22 at 07:50 PM

quote:
Originally posted by number-1

I will start and run the car a few times a month for half hour or so too



[Edited on 16/9/22 by number-1]


That's worse for the engine than leaving it six months not run at all!
You will fill the crankcase with moisture and the oil will never get hot enough to evaporate it.
You can turn it over with a breaker bar by hand if you are concerned about it seizing up,but otherwise leave it alone!

BenB - 17/9/22 at 09:21 PM

30 minutes not enough? I would imagine the engine would be well up to temp by then and any moisture long gone.

coyoteboy - 23/9/22 at 12:47 PM

Mm by 30 minutes idling my car is at about 90C oil temp. And if you're doing it a couple of times a month, that should be enough to cover battery drain.

I leave my tintop for 8 weeks at a time, I just remove the negative, but I have recently installed a 20W panel on the roofrack and a charge controller in the engine bay.