Solar panel battery charging

[thompsonbr87]

I have a "primitive" hangar. Walls, a roof, and a concrete floor. No power, running water, or anything else in the way of amenities. I already have a solar panel and charge controller to charge a battery which runs LEDs so I can at least have some light in the hanger and run some smaller electrical loads (either at 12V DC directly from the controller or through an inverter). Would it damage my airplane's battery to directly hook it up to the solar charge controller to recharge? Or would I be better off a product like BatteryMinder/BatteryTender off of my inverter?

Lead acid Gill if it makes a difference.

[rapid_ascent]

I think you would need someone who is more of a battery expert than me. I would think the safer solution would be to use an inverter and then use a charger that is made for your battery. The only downside of this approach is that it is not quite as efficient since each voltage conversion is not 100% efficient.

[ty1295]

I am sure some electronics are made to go between the panel and battery to be safe.

Off the shelf option might be a timer, so the invertor cycles for X minutes a day. Unless you have a drain, that should be plenty to keep it up to full power.

[Mich48041]

Several aircraft owners have reported that keeping a battery maintainer on the Odyssey PC680 does more harm than good. The battery will be happy if the plane is flown at least every couple of months. No battery charger is required if battery is AGM type.
As for damaging the battery with a solar charger, it all depends on the voltage and the length of time that it is connected. A smart battery charger will automatically lower the voltage as the battery approaches full charge.

[Mike D]

Short answer is you can charge the battery directly from the charge controller if your charge controller is compatible with your type of battery.
Longer answer is, it depends on what type of battery it is if it is a good idea to keep it fully charged all the time.
My advice is just fly the plane and don?t worry about the battery minder or charging.
If not flying for a while, then preserve the engine and take the battery out of the plane. When it gets below 70-80% then charge it up to about 90%

[mr.sun]

SunSaver Duo 25 amp charge controller should work with 300 to 400 watts of PV panel(s) at 12 VDC. Designed for dual battery systems in motor homes/boats.
Be careful of reverse polarity or shorts. Fuses are good. Breakers are better. Having daily resting cycles helps batteries I have found. Frankly, I don't think you need to recharge the PC 680 unless it gets badly discharged. I think I would find some used, but larger panels and feed a set of golf cart batteries thru a MPPT charge control at higher voltage.

[thompsonbr87]

I'm not looking to keep it hooked up regularly as a maintainer or trickle charger. Typically I fly enough that it is not a problem. Recently, though, I haven't been installing some new avionics instead of flying, and programming/troubleshooting has drained them down a bit. Just needing a bit of a recharge before attempting to crank the engine.

I know the Odyssey batteries have had trouble with chargers, which is why I mentioned that it is a Gill lead acid. I may switch to the Odyssey when my current one goes T.U., but for now it's not relevant.

From these replies and other threads, it seems like the most important thing is to not just leave it on any charger. I decided to do what I should've just done in the first place and RTFM. It said constant voltage was preferred to avoid overcharging. Since the controller on my solar system regulates the output voltage, it seems like it would be a safe way to accomplish this.

[Mike D]

Thinking about it a little more, if I were in your situation I would buy a solar generator of sufficient size to run a few lights and a battery charger. These are about $200 and can run a few items. Some come in kits that include solar panels.