Solar panel

[bro61021]

I just purchased a small 1.5 watt solar battery maintainer panel to keep my single 12 Volt battery charged while in storage. I would like to keep this unit connected while in storage, while traveling and while camping and connected to electric power.
The question is: will I do any damage to my RV, appliances, 12 volt converter, battery, or solar panel itself by being connected to electric power and solar at the same time.

[bro61021]

Originally Posted by bro61021

I just purchased a small 1.5 watt solar battery maintainer panel to keep my single 12 Volt battery charged while in storage. I would like to keep this unit connected while in storage, while traveling and while camping and connected to electric power.
The question is: will I do any damage to my RV, appliances, 12 volt converter, battery, or solar panel itself by being connected to electric power and solar at the same time.

This is what I purchased. Can I leave connected to the battery at the same time Im plugged into electric power?

[bro61021]

Originally Posted by bro61021

this is what i purchased. Can i leave connected to the battery at the same time im plugged into electric power?

[aeblank]

It's fine to leave it connected.

[RVPioneer]

I keep one of those on a riding mower that is stored in a shed without power. If it sits for 2 months it is usually necessary to run an extension cord and put it on a charger for a while. They don’t do much. I would not offer advice on whether or not it will damage any of your other components.

If there are any loads on the battery (CO2 or LPG detectors) while in storage that device will not be able to maintain a charge. I would recommend a 20w panel and charge controller to maintain a battery while in storage. Or take the battery home and keep it on a battery tender.

[Mark_K5LXP]

Good news - you can leave it connected whenever you like, as long as you like.

Bad news - this thing doesn't have enough power to do anything useful on an RV sized battery. You'd need a dozen of them to even get close.

Mark B.
Albuquerque, NM

[bro61021]

I should have mentioned that the RV will be stored outside in full Florida sun, when it's out and I have a battery disconnect when in storage. The battery should be fully charge when put in storage.

[epoucher]

How do I determine the correct size solar charger?

Would a 15 watt Battery Tender solar charger with controller be enough for one RV crank battery?

[Soppy]

A 1.5 watt panel can be left on indefinitely without any problems. The current is so low that it will barely overcome the self discharge of the battery. If there is any load on the battery , it will eventually become discharged.

[keymastr]

I have a 10 watt panel on my roof and it keeps my 2 6 volt batteries charged up even in winter as long as I don't forget to use the disconnect.

[Persistent]

Originally Posted by bro61021

I should have mentioned that the RV will be stored outside in full Florida sun, when it's out and I have a battery disconnect when in storage. The battery should be fully charge when put in storage.

I agree with others. It will not be damaged by leaving it connected.

Assuming your single battery is fairly new the 15 watt charger will keep it safe for up to 6 months if the battery is truly disconnected. Of course the battery would be ok without the charger as well

Charge the battery for 24 hours using your TT charger/converter. Disconnect the battery from the TT circuits. Wait 2 hours and check the battery voltage using a digital volt meter ($10 at hardware store). It should be above 12.7. Better if above 13.0.

Connect the solar. Check it again a month later (total 6 weeks). If it is 13.2 volts, it is working. Check it again in 3 months. If the battery voltage is 13.2 the solar charger is great. If it goes up to 13.8, that is too much. If it goes down to 12.4 the battery is fine but the charger is doing nothing. If it goes below 12.4 the battery needs to be charged using a more powerful device like your TT converter/charger more often.

[Persistent]

When the battery voltage is below 12.4 static voltage, it will slowly accumulate sulfate crystals on the plates. Full fast charging to 100% charge will remove thin layers. Thick layers are permanent damage to the battery.

[bro61021]

I was not really concerned about damaging the solar panels. I was concerned with damaging the RV converter, electrical system and/or battery by leaving the solar panels connected to the battery while hooked up to electric at the same time.