Solar 12v Battery Charger and Maintainer

FREE Energy from the sun. Specifically, a solar powered 12v battery trickle charger and maintainer for a car battery, mowers, a tractor, ATV, snowmobile, you name it… If it has a 12v battery, this will charge it. I have several of these particular solar chargers. Let me tell you about it, and give a recommendation or two.

Solar 12v Battery Charger Maintainer – Important Features

How Many Watts

We’re talking about a 12v battery charger/maintainer, not a fast charger. Rather, a good trickle charger.

In my opinion, a 20-watt solar-powered charger will provide enough slow charge and trickle charge to keep a 12v battery nicely topped off.

Depending on factors (sunlight, efficiencies, etc.) you’re looking at about 1 amp maximum charge current with a good 20-watt solar charger, while the floating charge voltage will typically be 13.8 VDC.

Maximum Power Point Tracking (MPPT)

It’s important to get one with built-in MPPT charge controller technology. It is a technique used to maximize energy extraction as conditions vary (more info). This can improve efficiencies by up to 30% depending on conditions.

Smart Charging

3-stage ‘smart’ charging is also important. This specfic type of solar 12v battery charger will typically begin with a bulk charge stage, then an absorption stage, followed by a float stage, which is much better for the battery.

Weather Rated

Be sure that it’s at least IP65-rated weatherproof for outdoor use.

Built-in Protections

Check for built-in protections including over-voltage, over-current, reversed polarity, and short-circuit protection.

Battery Types & Chemistry

I’ve chosen a solar-powered 12 VDC battery charger/maintainer that will work with the following battery type/chemistries:

• Lead Acid
• Deep Cycle
• Wet Gel Cell
• Maintenance-free
• AGM
• LiFePO4 Lithium

Sun Energise 20W
(amzn)

Solar Powered 12v Battery Charger/Maintainer Uses

I keep one of these solar chargers connected to the 12-volt battery in my snowmobile. Why? Because I’m tired of replacing dead batteries (winter can kill them fairly readily if you’re not careful)(related article about this at the end).

When Winter approaches, I cover the golf cart and store it under the deck until Spring. A 12v solar trickle charger gets connected to the starter battery, alleviating any concerns.

The old Ford tractor gets one too for the off-season. I will likely make a project of a more permanent mounting of the solar 12-volt battery charger up on the roll bar somewhere, out of the way.

I also use one to keep my electric fence battery charged up.

Here’s another 12v solar powered battery charger/maintainer from the same company. I bought one of these for my truck. You could use the provided suction cups to stick it on the windshield or window.

Sun Energise 20W (Lightweight w/Suction-Cups)
(amzn)

Got a vehicle that you don’t drive often? Consider a 12v battery solar charger (trickle charger, maintainer) on the dash. You could plug it into an accessory outlet (cig. lighter socket). Use one that’s always ‘live’ and not dependent on the key being ON.

Since vehicles tend to gradually consume battery power (even when off), I did get one for the truck, as an experiment. I found one that fit pretty well on the dash, and fairly matte black with minimal reflections on the windshield (if left there while driving).

Other uses would include keeping a 12-volt battery charged in an RV, camper, 4-wheeler, rider mower, motorcycle, a boat, you name it…

Connection Tip: These come with standard ‘quick connect/disconnect’ plugs. You can use the alligator clips, the cigarette lighter adapter, or bare-end terminals. For some batteries such as the smaller type on a wheeler, snowmobile, etc., I’ve installed the bare-end terminal adapters directly to the battery. This makes for a nice easy connect/disconnect for the solar panel charger (or other plug-in trickle chargers).

Prepping & Preparedness

From a prepping, preparedness, and sustainability point-of-view, I love using solar power. It’s not reliant upon anything external. When you have it, you’ve got free energy.

[ Read: Lead Acid Battery Freezing Point Temperature vs State of Charge ]

[ Read: Battery State of Charge Chart ]