12 volt battery chargers

[30.16florida]

Had some good success charging dual 12-volt batteries with a solar panel in an F-350. Interested in passing along additional 12-volt solar power tips to fleets. Looking for suggestions on portable panel mounts for companies that may leave vehicles unattended for extended periods. Dash mounts not always conducive for charging.

https://www.hardworkingtrucks.com/vi...solar-charger/

[SunEagle]

Hello 30.16florida and welcome to Solar Panel Talk

I am glad you have had some success using that solar battery tender. Unfortunately that panel is too small to properly "recharge" a depleted battery. It should work fine to keep a vehicle battery in float but it just doesn't have the amp output to recharge a battery on its own. The alternator would be the only proper way to recharge a vehicle starting battery.

[30.16florida]

Thanks for the feedback SunEagle. I should have clarified that the intent is to help instruct fleets on how to keep batteries in float while not in use. Portable panel stands of some kind that can be moved around a fleet's parking lot would be ideal. But portability might be impractical given wind gusts in some areas. Appreciate any thoughts on this.

[SunEagle]

I think the idea has merit. The biggest problem I see is where do you mount the solar panel so that it won't be stolen. I has to be outside and pointed at the sun for at least a few hours.

[Ninety-9 SE-L]

What's the float voltage? A 12V lead acid battery typically absorbs at 14.4V and floats at 13.2V. If you keep it at 14.4V indefinitely, you'll shorten the life of the battery.

A 15W charger will yield about 1A, so it's really only good for floating, not charging. Assuming it outputs good voltage, you're still really dependent on weather, shade, mounting the unit, and it's really only going to work for about 6-8 hours per day.

If you really want to maintain your work trucks, I highly suggest you buy a smarter battery maintainer that works consistently 24/7. I suggest the Noco Genius G4, which will maintain 4 vehicles at once. I'm a big fan of Noco's products.

[30.16florida]

Good point about theft, SunEagle. I thought the same. That's where dash mount chargers win the day. But if they're not getting adequate sun given vehicle position, etc., then obviously another route is needed. Think I'll look into dash mounted panels next and test a few. So many fleets have trailers, trucks and vans that are left unattended for long periods of time. Many fleets have transitioned to solar, particularly for their reefer trailers. The tops of trailers serve for good mounting areas. Class 8 tractors are also getting good results using solar to power HVAC and other equipment. It's the smaller class trucks and vans that don't seem to be getting as much attention. However, some larger vans (high-roof Transit) have made good candidates for roof mount panels.

Thanks for the tip on Noco Genius G4, Ninety-9 SE-L. I've been wanting to test their products. I'll get in touch with them. Battery Tender literature for the 15-watt solar charger does not list floating charge. However, they write that a fully charged 12-volt battery at rest should be showing at least 12.9 volts. They further explain that their maintainer will kick in once the battery is fully charged so perhaps that's 12.9? An LED will change from 'amber' to 'green' to indicate full charge and maintenance mode.

[bcroe]

Some maintainers will draw power back from the battery, if their power source goes away. Power
for that LED comes from somewhere. Avoid this type for things like solar which may have no
power much of the time and sometimes days or weeks with none at all. Bruce Roe

[30.16florida]

Good point on the LEDs. The lights cut off around sunset and come back on around sunrise.