Solar trickle charger, does it work to maint. battery in winter?

I used one with my car battery a couple years ago.
The battery was completely dead when I came back for home time.
Dead dead, not just jump and go dead. It seemed to have the exact opposite effect.

Now, I just disconnect the negative lead. No problems since then.

The battery won't lose much charge if it is not connected to anything.
Case in point... batteries in a store can sit for months and still hold a good charge when the customer buys it.

Don't need a trickle charge... just need nothing drawing a charge.

 

The truck draws .15 amps when it's not being used. Could be higher depending on the truck. Probably less on the older rigs.

So anything over .25 amps should charge the batteries. Albeit at a snails pace charging that low.

My car draws .13 amps.
It's been sitting in the garage for 2 months now. Waiting for repair. It fired right up when I took it out for bfast last week before tearing it down.

 

50w charger at 12v is 4.1 amps, consider that that is only when the suns angle is right.
most consider that a solar charger is 30% efficient (daylight hours, angle, clouds) so a 50w charger will max out at 1.3 amps to 3 batteries but average out at .5 amp/hours per battery during daylight hours.
Most modern tractors have a .05amp parasitic draw to maintain computer memory so that solar charger should keep the batteries up to 75% or better even with bad weather.

 

.15 amps parasitic.

 

I stand corrected

 

I just replaced batteries in the 579 I'm driving now. 2018 automatic.

Positive had .37 amps. Negative had .22 amps.

I don't know if there's a difference between auto and manual. 2018 vs. Newer or much older. Say 2000 or older.

 

Yes it will work, get an MPPT controller, more efficient. I would disconnect the batteries from the truck but if it is going to be a few weeks at a time before you run the truck, then just leave them. What ever you do, hook up the batteries FIRST, then the panel.

VW used to have in their catalog solar panel kits for their SUVs and Beetle, I have a few of them from VW for the vehicles that sit a lot, the last one I bought was 2020 and it was like $45 for a 30 watt panel you plug into the lighter.

 

Curious as to how one would use the lighter.

All the newer vehicles I've owned shut down with the car.

Not sure on the truck I'm currently driving.