Solar battery Chargers

AZMinyard

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Jun 26, 2008
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Just curious to find out if anyone has used one of the small solar battery chargers to charge/maintain their deep cycle battery.

I have a plug in charger now, but it seems like my battery is always loosing its charge, even though it is relatively new. I have a feeling it has to do with the heat here. I thought I might take advantage of the large number of sunny days here in AZ and get a solar charger for the battery, but wanted to see if anyone has had any experience with them first.
 

tashasdaddy

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Re: Solar battery Chargers

batteries do not like to be left uncharged, they should be fully charged, after use, water level checked, also. then the solar are fine for maintainers.
 

smclear

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Jul 14, 2008
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Re: Solar battery Chargers

They should work great providing you install them correctly. They'll need a regulator of some sort to prevent overcharging.

There are quite a few motorized boat lifts that use solar panels to 'maintain' the battery. Lots of info on the web if you look for it.
 

Silvertip

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Re: Solar battery Chargers

Most of the smaller solar chargers are 5W or less and do not require a regulator.
 

ED21

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Aug 26, 2003
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Re: Solar battery Chargers

I used a small solar charger(5 watt I think) to maintain a deep cycle battery on a small sailboat for years & it worked. No regulator, but it did have a diode to prevent the battery from discharging through the charger at night. That battery lasted the longest of any I ever owned. Never had an issue with overcharging or loosing electrolyte.
I would think Arizona would have plenty of sunlight to keep the battery charged.
 

NelsonQ

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Re: Solar battery Chargers

Most of the smaller solar chargers are 5W or less and do not require a regulator.

From what I've seen the smaller ones are 2.5W and 5W. Apparently (not my experience) the 5W works great but the smaller 2.5W doesn't (not sure why)

Not sure what you have but if you're buying one, might want the 5W.
 

joed

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Sep 28, 2002
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Re: Solar battery Chargers

2.5 watts at 13.5 volts = .18 amps
5 watts at 13.5 volts = .37 amps
I don't think you will over charge a battery at those rates. You will just barely maintain them. If they actually need charging best to apply a real charger.
 

AZMinyard

Petty Officer 2nd Class
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Jun 26, 2008
Messages
165
Re: Solar battery Chargers

So a 9 watt system should slowly charge and maintain then?
9 w @ 13.5v = .72 amps?
 

Boatist

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Apr 22, 2002
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4,552
Re: Solar battery Chargers

9 Watts at 13.5 volts would be .67 amps when the sun is high in the sky.
It will be lower in morning an evening or if it is cloudy. If you add a diode to prevent battery discharge at night then the charge rate is even lower.

I would say in a hot area like AZ where the battery self discharge will be higher you will be lucky to maintain the battery and do not think it will charge at all. Maybe on the longest days of the summer would get some charging.
 
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