| Solar-panel soldering : I use low
temp method to solder the wires on.
1. Heat up the soldering iron first until it can melt down the
solder
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Solar NiCD AA Battery Charger
Making use of our Mighty Sun
to
charge your battery
:-)
| Solar-panel soldering : I use low
temp method to solder the wires on.
1. Heat up the soldering iron first until it can melt down the
solder
|
|
| There are two versions of solar battery charger : one with the diode and one without. As you can see I'm using the one with diode here.The diode prevents the battery from discharging through the cells at night. If you don't have the diode handy, make sure you remove the battery at night to prevent discharge through the solar cells. |
| I recycled 1N4001 and battery holder from some technoscrap (junk), hooked it up to Panasonic 3766 solar-panel to charge the 2 AA NICD batteries |
| Although there is voltage drop across the diode, 3766 can juice up to 5.5V under the sun, so there is no problem to charge 2 AA batteries. (forward voltage drop of about 0.65 volts, quoted from Eric Seale, BFTGU) |
| Parts list :
AA NiCD battery : National P-60AAF, 1.2V 600mAh,
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| dsteink@dakotacom.net " Looks like it should work fine. I expect the charging time would be close to 25 hours of direct sunlight. You shouldn't need any type of charge controller, just the 1n4001 to prevent reverse current flow. David " |
| Russ (jubal@my-deja.com) " I wouldn't worry about a diode at your 33ma
current. Night time leakage current is low (1/1000 or less x rated output).
A diode would probably cut your charge rate to about 0.0. If you have more
than 1 such panel, you might try them in series as well as parallel and
see which way gives you more current. I expect 2 in series at a real 33ma
(voltage 5-10?) will beat 2 in parallel. As you can see, I'm expecting
about 60% voltage & current under load. A cheap digital VOM ($7?) can
measure currents up to 200ma.
Note that you will not have open circuit voltage or short circuit current under normal recharge. Both will be less, and I would expect about 100mah per day when you get 5 hrs. of average sun, less if the batteries aren't completely dead. I used to have one of the 4- AA chargers with about a 8 sq. inch solar charger (nominally 50ma). It would recharge them in about a week, if it didn't rain too much. No diode, just left them in a window till I needed them again. Ni-cads aren't particularly bothered by being overcharged and you would probably not overcharge them at that charge rate, anyway. Even new ni-cads can only use about 80% of the energy you supply to recharge. " |
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