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Solar battery charger.
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TOPIC: Solar battery charger.

Solar battery charger. 3 months, 2 weeks ago #558281

  • vRSG60
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I have a solar battery charger which appears to be doing bugger all. Bike battery still ran down even with it connected, yes I know it's winter but it's not dark all day long.

Am I right in thinking that the output should always be 12V and the Amps will change depending on how much power is available from sunshine? Or will the Voltage differ too?

Mine is putting put no where near 12V. More like 3 or 4 Volt.

It has a diode so it's not supposed to reverse drain the battery when it'd dark.
Out On The Floor - Keep The Faith

Re: Solar battery charger. 3 months, 2 weeks ago #558289

  • Tramp
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In the northern hemisphere the angle of the sun gives bugger all solar ...ive a 150w pannel on my camper and get maybe 2 hours on the southcoast ...it also needs directing continually to be of optimum use...mine tracks the sun when its out too...get a bike with a dynamo lol..
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Re: Solar battery charger. 3 months, 2 weeks ago #558307

If its only outputting 12v it wont overcome the batterys internal resistance and thus charge it hence why the stator outputs 13.8v or thereabouts.How big a panel is it and many will only output mA [milliamps] i.e. 1000mA = 1 amp
Last Edit: 3 months, 2 weeks ago by Andi_Archer.

Re: Solar battery charger. 3 months, 2 weeks ago #558308

In winter, in the UK, you'd expect to get about 10% of rated output from a solar cell, assuming it's correctly aligned, over an average week.

When you say you're getting 3-4 volts is that when it's connected to the battery or when it's just sitting on the bench?

Basic solar cell gives about 0.6V, multiple cells need to be wired in series to achieve the 14V plus to charge a battery. Cheap assembles, rather than having 12 or more cell incorporate some circuitry charge in pulses which means that when you come to measure the voltage (which can only be done attached to the battery) you get a varying voltage which can be difficult to see on many digital meters.

Lesson over now class, sorry.

Could well be that alarm / immobiliser/ coupled with low panel output and low temperatures means that it can't keep up with the demand, might be a mains powered battery tender is your only option.
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Re: Solar battery charger. 3 months, 2 weeks ago #558319

  • vRSG60
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It's the same as this. No electricity in my garage. It's a mile from my house.
I'll keep running it for 10 minutes or so once or twice a week.
I'd take the battery off and keep it on a trickle charge at home but I have a tracker fitted that needs voltage to it. Might be this that's gradually draining it.

3 - Volts is bench testing it. Not connected to a battery, so I guess this will never charge a battery because it's less than the 12V
Out On The Floor - Keep The Faith
Last Edit: 3 months, 2 weeks ago by vRSG60.

Re: Solar battery charger. 3 months, 2 weeks ago #558320

  • Cone
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Ah i did a bit of research on this a while ago - is it a home made charger from a cell if so you will be draining the battery at night more than the charge you put in - you need a diode installed to prevent this night drain!

Re: Solar battery charger. 3 months, 2 weeks ago #558323

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Blurb says it has a diode.
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Re: Solar battery charger. 3 months, 2 weeks ago #558358

I used a solar charger to top up the battery on a car we did not use much. Always kept the battery charged up enough to start no problem. Before that if the battery dropped below about 12.8v it would lock out the starter circuit and refuse to try and start.
Used a cheap folding panel from Maplin 6? years ago. Just left it on the dash, it faced north so did not get direct sun on it but still produced enough power.
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Re: Solar battery charger. 3 months, 2 weeks ago #558414

  • qcnr
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How long does it take to change batteries?
Have 2 of them one at home(charging) one on the bike. Swap them every time you give the bike a turnover.
You could be buggering the battery if the solar charger isn't charging it properly.
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Re: Solar battery charger. 3 months, 2 weeks ago #558476

  • vRSG60
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Not long now I've figured out how to.


qcnr wrote:
How long does it take to change batteries?
Have 2 of them one at home(charging) one on the bike. Swap them every time you give the bike a turnover.
You could be buggering the battery if the solar charger isn't charging it properly.
Out On The Floor - Keep The Faith
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