Somebody gave me a new solar battery charger. I tried it out on a cloudy day and it is only putting out like 10.5 volts. Will low voltage hurt a 12 volt battery? I would like to leave it on a battery and not have to unhook it if it is cloudy out.
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Solar Battery Charger
- Thread starter johninct
- Start date
FigureItOut
Well-known member
It won't hurt it. If you were to say, put a battery on it at 10.5 volts you'd be draining the good battery to charge the bad one, but a charger isn't going to be drawing any current.
To be certain, see if there's any indication of power being drawn. Current has to "do" something. You'd most likely see it generating heat, so feel the charger and cables for any sign of heat being generated. No warmth, no LEDs or whatever on the charger, means you're doing no harm.
Sent from my SAMSUNG-SGH-I337Z using Tapatalk
To be certain, see if there's any indication of power being drawn. Current has to "do" something. You'd most likely see it generating heat, so feel the charger and cables for any sign of heat being generated. No warmth, no LEDs or whatever on the charger, means you're doing no harm.
Sent from my SAMSUNG-SGH-I337Z using Tapatalk
sicnarf247
Active member
- Joined
- Nov 5, 2015
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- 44
is it one of those charger you hook the the lighter in the car?
SantaAna12
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- Mar 1, 2012
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Diode?
wolf_from_wv
Well-known member
Diode?
It should have a diode to keep it from discharging the battery when the sun isn't very bright. Does it have a model number to look up online to see if it does?
kd3pc
Well-known member
you really need a charge controller and a diode on the PV panel, at a minimum. Without those, your battery can be damaged, if you leave it connected full time and something shorts or fails in the panel.
more info would help.
more info would help.
is it one of those charger you hook the the lighter in the car?
Yes. I was thinking of making it a clamp on and/or able to plug into my BatteryMINDer plugs.
jallyn
Well-known member
This charger likely has such a small charge rate it won't damage a battery, maybe 1.5 Watts. That would only be about one-tench of an amp during ideal conditions. Only during the 3 hours per day of direct sunlight on a clear summer day will it actually do anything. It is a trickle charger that can keep a battery topped off over the summer months.
jkwilson
Well-known member
You need more voltage from the panel than the battery in order to charge. A battery charger typically runs a little less than 15V to charge a 12V battery. If the panel only puts out 10V, it will not charge a 12V battery.
You need more voltage from the panel than the battery in order to charge. A battery charger typically runs a little less than 15V to charge a 12V battery. If the panel only puts out 10V, it will not charge a 12V battery.
I know it won't charge the battery with low voltage but will it hurt the battery? I want to put it on an old PayLoader that I have that won't run for months but gets good sun.
jkwilson
Well-known member
I know it won't charge the battery with low voltage but will it hurt the battery? I want to put it on an old PayLoader that I have that won't run for months but gets good sun.
Even if it is protected from discharging the battery, it won't help anymore than a piece of cardboard. If it can't produce an open circuit voltage above 13V it's either bad or not a 12V panel. Either way it is worthless for a 12V battery. Nothing good can come from connecting it, but bad things could happen.
It's just like air pressure. You can't inflate a tire to 65psi with a tank filled to 30psi.
jallyn
Well-known member
I know it won't charge the battery with low voltage but will it hurt the battery? I want to put it on an old PayLoader that I have that won't run for months but gets good sun.
Should work. These little chargers are meant to be used for exactly what you are talking about...a 12V battery left unattended for months with good sun available. I bet ten to one since it has the cigarette lighter adapter it already has a diode built in to protect the battery from being discharged through the solar panel. If you want to test it put the panel on a known good battery for a couple days. If the battery doesn't discharge you are good to go.
AnEv942
Well-known member
Lower panel voltage than battery will not hurt battery, wont do anything. Output voltage will vary with available sun, down to zero during the night. Tested under full sun should show closer to 17v or better. You dont need a controller on a 1 watt panel. Safe.
Cigarette plug likely has a fuse-
Note it is a solar trickle maintainer. Meaning under the most optimum conditions its only working few hours out of 24. Any charge is better than none though. But dont leave your jumper cables in the shop if loader sets for months.
Cigarette plug likely has a fuse-
Note it is a solar trickle maintainer. Meaning under the most optimum conditions its only working few hours out of 24. Any charge is better than none though. But dont leave your jumper cables in the shop if loader sets for months.