I found 2 AGM batteries

Wild Brambles

Wild Brambles

Free Member
Joined
Nov 11, 2019
Posts
431
Likes collected
1,687
Location
Hampshire
Funster No
66,761
MH
Van conversion
Exp
2 years
Last night I picked up 2 AGM batteries. in a lay-bye The date on them is 2016, and they show 12.75 volts on the meter. They are small - only 18aH, but they would fit nicely under the bonnet of my van. I'd like to use them to start experimenting with solar power. I've been given a cheap controller, and I would like to keep the setup as an auxiliary after I install a larger system when I know what I'm doing. So here are the questions.

Is 36aH worth the effort? I'm hoping I can use it to recharge my netbook, or maybe run a 12 volt TV.
What size of solar panel would you suggest I should use with them?
 
Wild Brambles said:
Last night I picked up 2 AGM batteries. in a lay-bye The date on them is 2016, and they show 12.75 volts on the meter. They are small - only 18aH, but they would fit nicely under the bonnet of my van. I'd like to use them to start experimenting with solar power. I've been given a cheap controller, and I would like to keep the setup as an auxiliary after I install a larger system when I know what I'm doing. So here are the questions.

Is 36aH worth the effort? I'm hoping I can use it to recharge my netbook, or maybe run a 12 volt TV.
What size of solar panel would you suggest I should use with them?
Click to expand...
Not worth the Hassel of them being duds, you can get a perfectly adequate battery new off eBay for less than forty quid.
 
Well that is £80, and at the moment I'm in educational mode before I spend anything. I've also got an 85aH leisure battery that might fit in to the space if they don't work.
So who can help me by answering the questions in the OP?

Subscribers  do not see these advertisements

 
36Ah will charge your netbook no problem, maybe ok to watch TV for a few hours. Get the biggest solar panel you can fit/afford.
 
I can afford to cover the roof in panels, but my problem is knowing which panels to choose, and how to install and connect them. With a matched pair of 2 volt AGMs, I wondered if it was worth experimenting with 24 volt in case I want to upgrade to a larger vehicle. I don't have any 24 volt appliances, so that is probably not a sensible path at this moment.

I'm very much a novice in the world of digital nomads, and it is only recently that I have decided that it is a preferred life style choice for me. I know about the 2 legged rats in the bricks and mortar world, and I'm starting to learn about the 4 legged ones in the nomadic world. On balance, I think the 4 legged ones are less of a problem.

I will develop a budget secondary system using either the AGMs or the 85aH battery. I'll dig out the controller that I have been given, and maybe you guys can comment on it.
 
If your not going to use the batteries you found, take them to a scrap yard, they are worth a couple of squid each for the lead content, price varies from 30p to 50 p per kg. (y)
 
That was why I picked them up. I've got an account with EMR ( and a couple of others ). It's still active from the days when I owned a small recycling business.
 
If you just want to experiment then go for and if you have a controller already then you only need a panel. :)

Have a look on eBay for secondhand ones. There are some good 150W around. Don't worry about the type especially if you have plenty of roof space, polycrystalline will be fine.

Subscribers  do not see these advertisements

 
The roof bit is a problem. I need to fix the leaks, and also I need to decide where to put the chimney. I did buy a cheap panel from Aldi a while ago. The idea was to hang it on the driver's window. I can't remember the output, but it's probably something like 25 watts. I thought of a suitcase panel, but I don't sit still long enough to make it viable. Maybe I could put a fake window on the side. :)
 
  • Like
Reactions: DBK
It looks as if I should forget the 24 volt experiment. I don't have any 24 volt appliances, and stepping it down to 12 volt seems a bit mad, given the small amout of power available in the batteries. The main appeal was to connect the batteries in series, rather than in parallel, as I gather that is more reliable, and it reduces wiring size.
 
Wiring panels in series can have some advantages in low light, but I can't see any advantage in wiring your 12v batteries in series unless you need 24v.
 
These seem good for the price and size.
 
If they are no good take them to a scrapyard - should get about 50p a kilo for them. :D :D

Subscribers  do not see these advertisements

 
Sounds like you're an inveterate skip rat like me !
Does your cheap solar controller support an AGM's charging regime ?
They've probably come off a mobility scooter and are on their way out ? Try putting a load on them like with a headlamp bulb for example and see what voltage they show then, it might just plummet !
 
I've got a professional battery tester. I used to collect the "dead" batteries from garages.
 
Wild Brambles said:
Last night I picked up 2 AGM batteries. in a lay-bye
Click to expand...
pappajohn is gonna kill you when he realises it's you who nicked them off the mobility scooter in his MH when he stopped for a cuppa! :rofl:
 
I'm charging the batteries at the moment. The first one is reading 13.3 volts now. I'll check to see if they are holding their charges later. I'm hoping that they were dumped because the dumper just wanted to increase his storage capacity.

Afternoon update - trhey are both holding at 12.75 volts, and I believe that is correct for AGM batteries.
 
Have you put a load on them ?

Subscribers  do not see these advertisements

 
DBK said:
If you just want to experiment then go for and if you have a controller already then you only need a panel. :)

Have a look on eBay for secondhand ones. There are some good 150W around. Don't worry about the type especially if you have plenty of roof space, polycrystalline will be fine.
Click to expand...
And some damp string:D(y)
Well worth the effort and experiment, great learning curve
worth while tying your mini solar system to your starter battery too
 

Join us or log in to post a reply.

To join in you must be a member of MotorhomeFun

Join MotorhomeFun

Join us, it quick and easy!

Join us

Log in

Already a member? Log in here.

Latest journal entries

Back
Top