solar charger for rv deep cycle battery.

[spasm3]

Rather than run a 150ft drop cord to put the battery minder on my rv battery during the winter. ( or hauling it into the garage). I was thinking of one of these. Anyone used one? i see two i'm interested in.

http://www.walmart.com/ip/Schumacher-Electric-Schumacher-Electric-Solar-Charger/21037288

or

http://www.radioshack.com/product/index.jsp?productId=11540104

 

[mikefxu]

http://www.amazon.com/Schumacher-SP-200-...c+Solar+Charger

"After much contemplation and research,,, and calling the manufacturer I've been informed (buy the manufacturer) that this unit does NOT have any method of charge control. Beware! ... you can easily overcharge your battery(s) with this unit. Overcharging can cause serious irreparable damage to your battery. Therefore, unless you're continually monitoring the charge state, and can disconnect this charger at the appropriate point, you need to use a charger that incorporates a charge controller. Don't use this unit as a "connect it and forget it" method of keeping your batteries charged or "topped off". You need something that has a charge controller. 73"

 

[spasm3]

Originally Posted By: mikefxu
http://www.amazon.com/Schumacher-SP-200-...c+Solar+Charger

"After much contemplation and research,,, and calling the manufacturer I've been informed (buy the manufacturer) that this unit does NOT have any method of charge control. Beware! ... you can easily overcharge your battery(s) with this unit. Overcharging can cause serious irreparable damage to your battery. Therefore, unless you're continually monitoring the charge state, and can disconnect this charger at the appropriate point, you need to use a charger that incorporates a charge controller. Don't use this unit as a "connect it and forget it" method of keeping your batteries charged or "topped off". You need something that has a charge controller. 73"


Thats what i am worried about.My rv converter will overcharge so leaving it plugged in is a bad idea. If unsure i will just use the battery minder i have on a drop cord.

 

[JHZR2]

Walmart? LOL.

Id buy the Battery Minder or Battery Tender solar ones. The "tender" brand has all waterproof electronics and just connects us. I think the "minder" brand has the electronics mounted someplace out of harms way, which would be more optimal as far as Im concerned...

I dont have the solar, but I have minders and tenders to support my vehicles and have been happy wiht both. I dont know that there is a real valid say on which is better than the other, though the minder type may do some additional desulfidation.

 

[spasm3]

Originally Posted By: JHZR2
Walmart? LOL.

Id buy the Battery Minder or Battery Tender solar ones. The "tender" brand has all waterproof electronics and just connects us. I think the "minder" brand has the electronics mounted someplace out of harms way, which would be more optimal as far as Im concerned...

I dont have the solar, but I have minders and tenders to support my vehicles and have been happy wiht both. I dont know that there is a real valid say on which is better than the other, though the minder type may do some additional desulfidation.


I have the battery minder, i will probably just use that. Just was thinking about not putting the battery in the garage or running the drop cord. I'll probably put it in the garage.

 

[RiceCake]

Originally Posted By: mikefxu
You need something that has a charge controller. 73"


"73"...guy is a HAM radio/amateur radio operator so I'd take his review into good consideration. The lack of proper voltage limiting means its a pretty lackluster controller. I honestly think most of these rely on the sun being dim enough that it doesn't overcharge during the day, or doesn't overcharge a lot, and then at night the battery can rest back down in voltage for another cycle.

Probably wouldn't ruin a wet cell battery for awhile but it'll likely lead to loss of water in the electrolyte from long term overcharge/discharge.

 

[JHZR2]

Originally Posted By: spasm3

I have the battery minder, i will probably just use that. Just was thinking about not putting the battery in the garage or running the drop cord. I'll probably put it in the garage.


But they make solar ones. I like the idea of solar, just buy a good one!

 

[Loobed]

Can you connect a cheap old fashion voltage regulator between the solar charger and your battery? Maybe somehow connect the wires from the solar charger to the voltage regulator inside the alternator.

 

[GMBoy]

Originally Posted By: mikefxu
http://www.amazon.com/Schumacher-SP-200-...c+Solar+Charger

"After much contemplation and research,,, and calling the manufacturer I've been informed (buy the manufacturer) that this unit does NOT have any method of charge control. Beware! ... you can easily overcharge your battery(s) with this unit. Overcharging can cause serious irreparable damage to your battery. Therefore, unless you're continually monitoring the charge state, and can disconnect this charger at the appropriate point, you need to use a charger that incorporates a charge controller. Don't use this unit as a "connect it and forget it" method of keeping your batteries charged or "topped off". You need something that has a charge controller. 73"



How can a solar charger overcharge? I mean, really..think about it. You probably will only get the max charge rate a few hours a day based on the position of the sun and charger then you have no charging all night long and overcast days, etc. Sounds like it will do fine.

 

[JHZR2]

It could be not an overcharge per se, but rather an excessive voltage that causes excess electrolysis of water and then a dry-out. That would really be my gues with cheap electronics.

 

[GMBoy]

Originally Posted By: JHZR2
It could be not an overcharge per se, but rather an excessive voltage that causes excess electrolysis of water and then a dry-out. That would really be my gues with cheap electronics.


Didn't think of it that way. It probably is cheap.

 

[wrcsixeight]

Anybody else notice the 2.4 watt number? That rating is in direct sun, aimed directly at the sun, not at an off angle, through windshield glass. The linked panel would struggle to add 1 amp hour to the~ 100 a/h battery in a single winter day. The battery could possibly self discharge more than that.

I doubt 2.4 watts could get a RV sized battery up to gassing voltages. If the RV battery is not unplugged from all parasitic drains like CO detectors, this 2.4 watt panel is a complete waste. The OP will return to dead house batteries.

Some of these panels do not have blocking diodes so they do not drain the battery at night.

You are better off removing the battery, putting it in your garage on a battery tender/minder, or a regular charger on a timer for 15 minutes a day every other day.

 

[spasm3]

Originally Posted By: wrcsixeight
If the RV battery is not unplugged from all parasitic drains like CO detectors, this 2.4 watt panel is a complete waste. The OP will return to dead house batteries.

Some of these panels do not have blocking diodes so they do not drain the battery at night.

You are better off removing the battery, putting it in your garage on a battery tender/minder, or a regular charger on a timer for 15 minutes a day every other day.


In the garage it goes!!

 

[GMBoy]

Originally Posted By: wrcsixeight
Anybody else notice the 2.4 watt number? That rating is in direct sun, aimed directly at the sun, not at an off angle, through windshield glass. The linked panel would struggle to add 1 amp hour to the~ 100 a/h battery in a single winter day. The battery could possibly self discharge more than that.

I doubt 2.4 watts could get a RV sized battery up to gassing voltages. If the RV battery is not unplugged from all parasitic drains like CO detectors, this 2.4 watt panel is a complete waste. The OP will return to dead house batteries.

Some of these panels do not have blocking diodes so they do not drain the battery at night.

You are better off removing the battery, putting it in your garage on a battery tender/minder, or a regular charger on a timer for 15 minutes a day every other day.


That's sort of what I was saying.

 

[JHZR2]

Originally Posted By: wrcsixeight
Anybody else notice the 2.4 watt number? That rating is in direct sun, aimed directly at the sun, not at an off angle, through windshield glass. The linked panel would struggle to add 1 amp hour to the~ 100 a/h battery in a single winter day. The battery could possibly self discharge more than that.

I doubt 2.4 watts could get a RV sized battery up to gassing voltages. If the RV battery is not unplugged from all parasitic drains like CO detectors, this 2.4 watt panel is a complete waste. The OP will return to dead house batteries.

Some of these panels do not have blocking diodes so they do not drain the battery at night.

You are better off removing the battery, putting it in your garage on a battery tender/minder, or a regular charger on a timer for 15 minutes a day every other day.


The bigger batteries have far lower impedances, so far lower overpotential is necessary to drive current in. It may be about good enough to "maintain", certainly not do anything else. Id imagine that as the battery self discharges due to thermal swings and parasitics, this wouldnt keep up. It just offsets.