Solar battery chargers / maintainers... opinions

[5030]

Like to get a good one, not for my tractors but for my car and I need some input as to what works and what don't. Lots to chose from so I'm pretty sure some are duds and some work as advertised.

I have parasitic loss with my car so if I don't use it regularly, the battery gets weak.

 

[Reb954]

This is what I use.

Amazon.com: Sunforce 5812 Coleman 2 Watt Solar Panel Battery Maintainer: Automotive

Bought my first one 3 years ago, just bought 2 more a few weeks ago. The first one is still running strong. These are not weather proof so keep them inside the car.

 

[LittleBill21]

i use this for a car that doesn't move for 6months

Amazon.com : ECO-WORTHY 12 Volts 5 Watts Portable Power Solar Panel Battery Charger Backup for Car Boat Batteries : Garden & Outdoor

 

[Roadworthy]

Most cars today have a parasitic loss due to all the electronics involved. You may wish to disconnect a cable at the battery to determine the rate of loss on your car. You can then select a charger which puts out slightly more than that amount of current.

 

[Doofy]

I left the 4 wheelers battery hooked up to a solar charger all winter and it fried the battery. This was 5 or so years ago so maybe they've improved.

I would just install a Master Disconnect on the battery. You can get a manual one or electronic. ...or you can find the circuit with the parasitic draw and fix the problem. Most parasitic draws are very minimal and a vehicle should start after being unused for a month or two. If your battery discharges in several days then you have a bad battery or a super parasitic draw. The diodes in the alternator can fail and drain the battery too (and yet, still work).

 

[cooksmtn]

I've used an earlier version of this 1.5 Watt Solar Battery Charger
for quite a few years. 1.5 watts is about 1/10 amp which is not going to fry an automotive battery.
The chargers go to about 13.2 volts.

I have vehicles that can sit for months, and these have made a difference.

 

[ultrarunner]

Been thinking of getting several since the 6 volt tractors were moved to the Squeeze Barn which is some distance from electricity.

Seems everyone has 12 volt models...

 

[RalphVa]

The only battery tender that's really reliable is an outdoor Battery Tender that plugs in. That's what works on the battery for our diesel generator. That battery powers both the generator's LCD panel plus the auto/on/off panel inside the house. Tried a 5 watt solar panel on it, and it just wasn't enough.

Have 2 approximately 10 watt panels on the battery of our remote gate. Still have to bring the battery in at least once/yr for full recharge.

Had a 5 watt panel on the fence charger. Replaced it with a 10 watt and put a Battery Tender in between the panel and the battery to keep from overcharging the battery. Had to recharge the battery recently.

Ralph

 

[Gary Fowler]

If you use any of the insurance company monitors like Allstate's Drivewise module then please note that they have massive parasitic battery drain. They will drain a new battery in just a couple of weeks of inactivity. If you use one of those and dont drive your vehicle frequently, then you need some sort of trickle charger of at least 3 amps.

 

[PEJ5]

I have a 2Watt that I do not use much. Knowing more about solar, I would go with the 5 watt noted in response 3 above. I have never had to charge my fence, but something with a battery (but no alternator), really needs between 40w and 150w and a proper charge controller to maintain a deep cycle battery. Battery size and solar panel size should be calculated to get a good working solution.