Solar 12v trickle charger for winch battery?
Discussion
I want to install a small 12v winch + battery on my trailer for loading/unloading at the track. My issue is how to keep this trailer battery charged up.
The car has dual 7-pin trailer sockets, but I read conflicting information about using these to try and charge the battery on the trailer, so wondering if an easy option would be to run a 12v solar trickle charger bolted permanently to the trailer itself (which lives outside). The winch will be used infrequently - 4 times for each track event which will be around once a month, so pretty sure a fully charged battery will handle this without issue.
Could I wire up a solar charger and forget about it? Or will I need another source?
Ideally if I could charge while driving from the grey 7S plug that would be great, but reading all sorts of things about needing heavy gauge wire and the need to alter the tow vehicle wiring which I'd rather not get involved with...but any reasonable alternative suggestions here are welcome.
The car has dual 7-pin trailer sockets, but I read conflicting information about using these to try and charge the battery on the trailer, so wondering if an easy option would be to run a 12v solar trickle charger bolted permanently to the trailer itself (which lives outside). The winch will be used infrequently - 4 times for each track event which will be around once a month, so pretty sure a fully charged battery will handle this without issue.
Could I wire up a solar charger and forget about it? Or will I need another source?
Ideally if I could charge while driving from the grey 7S plug that would be great, but reading all sorts of things about needing heavy gauge wire and the need to alter the tow vehicle wiring which I'd rather not get involved with...but any reasonable alternative suggestions here are welcome.
cptsideways said:
Yes your plan will work fine, wifey had a quad bike at the farm that was only used occasionally. Stuck a 12v solar panel outside the barn door & plugged into the battery. Always charged up when needed it.
It was only a 1ft sq panel & about £15 with battery terminals etc
Sounds good. How robust are these panels if I mount it to the top of the trailer and whap down the motorway at warp 8?It was only a 1ft sq panel & about £15 with battery terminals etc
Order66 said:
cptsideways said:
Yes your plan will work fine, wifey had a quad bike at the farm that was only used occasionally. Stuck a 12v solar panel outside the barn door & plugged into the battery. Always charged up when needed it.
It was only a 1ft sq panel & about £15 with battery terminals etc
Sounds good. How robust are these panels if I mount it to the top of the trailer and whap down the motorway at warp 8?It was only a 1ft sq panel & about £15 with battery terminals etc
eltax91 said:
Make it removable and stow it whilst you are on the move? Then rig it up when it’s going to stand still long enough to charge the battery?
I'm really lazy and that sounds like effort, I'd rather install and forget about it. I've found the panels at about £30 for 25w which seems to be enough to do the job, so I'll give it a try permanently mounting it...if it breaks it'll be £30 of education for me 
Order66 said:
I want to install a small 12v winch + battery on my trailer for loading/unloading at the track. My issue is how to keep this trailer battery charged up.
Easiest is probably just to keep the trailer battery on a mains charger/conditioner, and only fit it when needed...Order66 said:
The car has dual 7-pin trailer sockets, but I read conflicting information about using these to try and charge the battery on the trailer
Then pin 2 (blue) on the 7S (white/grey lid) socket should be ignition +12v, intended for battery charging.Order66 said:
Ideally if I could charge while driving from the grey 7S plug that would be great, but reading all sorts of things about needing heavy gauge wire and the need to alter the tow vehicle wiring which I'd rather not get involved with...but any reasonable alternative suggestions here are welcome.
Unless whoever fitted the sockets was a halfwit who ignored the standardised wiring, it'll be done. <passes multimeter>Order66 said:
Sounds good. How robust are these panels if I mount it to the top of the trailer and whap down the motorway at warp 8?
They're regularly put on top of motorhomes and caravans.Order66 said:
I've found the panels at about £30 for 25w which seems to be enough to do the job
25w peak sounds like it's not going to do much charging at all.cptsideways said:
Yes your plan will work fine, wifey had a quad bike at the farm that was only used occasionally. Stuck a 12v solar panel outside the barn door & plugged into the battery. Always charged up when needed it.
It was only a 1ft sq panel & about £15 with battery terminals etc
Don’t forget the quad alternator would have charged the battery when running.It was only a 1ft sq panel & about £15 with battery terminals etc
Op will be draining the battery and then only topping up with solar. Based on my own experience I think he’ll struggle with a small cheap panel, and even a more purpose designed caravan / boat one might not cope.
If your leaving it on permanently you only need a small panel. Overcharging is worse than under. So long as there is a regulator in the system it will be fine, there a few on ebay for just this purpose.
The panels are pretty simple things, our quad one has worked for several years fine. I have a few other solar projects including a campervan with a 200w system for those kinds of power you need a solar controller to not overcharge.
The panels are pretty simple things, our quad one has worked for several years fine. I have a few other solar projects including a campervan with a 200w system for those kinds of power you need a solar controller to not overcharge.
To be at its best, solar needs direct sunshine. Shadows or clouds greatly reduce solar output so if your trailer is shaded by trees it'll be a non-starter.
In winter you'll get about a quarter of the power that you would in summer, due to day length and sun strength.
How much power do you think you're going to need? And will you need more in summer, autumn, winter or spring?
In winter you'll get about a quarter of the power that you would in summer, due to day length and sun strength.
How much power do you think you're going to need? And will you need more in summer, autumn, winter or spring?
Order66 said:
eltax91 said:
Make it removable and stow it whilst you are on the move? Then rig it up when it’s going to stand still long enough to charge the battery?
I'm really lazy and that sounds like effort, I'd rather install and forget about it. I've found the panels at about £30 for 25w which seems to be enough to do the job, so I'll give it a try permanently mounting it...if it breaks it'll be £30 of education for me TooMany2cvs said:
Unless whoever fitted the sockets was a halfwit who ignored the standardised wiring, it'll be done. <passes multimeter>
Is it really as simple as just connecting the switched 12v from the grey plug to to +ve terminal on the trailer battery? My online reading tells of tales of woe doing this and ensuring there is a split/charge relay or wire thicker than a tree trunk otherwise the world will implode.eltax91 said:
If you are really lazy then get a tirfor instead of the 12v and you have nothing to even make work.
That looks like manual labour....I didn't get this fat working a lever myself you know!Anyway, I've ordered the solar panel and charge controller for a grand total of £40.....if anyone is interested I'll report back when done.....
Bin the battery on the trailer and get a really long custom jump lead to go to the battery on the car. I have the same on my trailer - there is an Anderson jack next to the battery box in the Land-Rover and another Anderson on the trailer. Works well, and as you’ve just drive to where ever you are loading, the battery is never flat.
Order66 said:
TooMany2cvs said:
Unless whoever fitted the sockets was a halfwit who ignored the standardised wiring, it'll be done. <passes multimeter>
Is it really as simple as just connecting the switched 12v from the grey plug to to +ve terminal on the trailer battery? My online reading tells of tales of woe doing this and ensuring there is a split/charge relay or wire thicker than a tree trunk otherwise the world will implode.The wiring obviously needs to be substantial enough for the charge that's coming through. But that's likely to be less than the winch is drawing from the battery.
Again, the car end should be good, unless wired by a halfwit.
rxe said:
Bin the battery on the trailer and get a really long custom jump lead to go to the battery on the car. I have the same on my trailer - there is an Anderson jack next to the battery box in the Land-Rover and another Anderson on the trailer. Works well, and as you’ve just drive to where ever you are loading, the battery is never flat.
Want to also load/unload with no tow car attached, so prefer the battery on trailer.Well for anyone who cares in the slightest, the winch/battery and solar panel are all installed and working brilliantly. Even on a very grey/wet late afternoon in Scotland the panel is giving out enough juice to charge the battery.
As an added bonus it gives me a couple of USB sockets in the trailer to charge up the GoPro on the way to the track.
Overall a very satisfying bit of DIY.
As an added bonus it gives me a couple of USB sockets in the trailer to charge up the GoPro on the way to the track.
Overall a very satisfying bit of DIY.
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