battery charger for smartech skylark
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battery charger for smartech skylark
Hello again:
I seem to have fried a my batteries because of not really monitoring the dumb charger that the factory provides for my little heli. I am going to buy new batteries, but I don't know if anybody have any siggestions or knows where to buy a more intelligent charger, which won't kill my battery packs. Sometimes is really not possible to monitor the batteries while they are charging...
Also, if I stick with the dumb charger, whats the best way to monitor the batteries. I know one is the temperature, but what should the voltage be when the pack is all charged?
thanks again,
guillermo
I seem to have fried a my batteries because of not really monitoring the dumb charger that the factory provides for my little heli. I am going to buy new batteries, but I don't know if anybody have any siggestions or knows where to buy a more intelligent charger, which won't kill my battery packs. Sometimes is really not possible to monitor the batteries while they are charging...
Also, if I stick with the dumb charger, whats the best way to monitor the batteries. I know one is the temperature, but what should the voltage be when the pack is all charged?
thanks again,
guillermo
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RE: battery charger for smartech skylark
gmozavala,
There are many types of battery chargers out there. Depends on how much you want to spend, or how fancy you want it.
I am using the supplied wall charger, and am a Comp Engineer. The magic number is:
If your wall charger specifies say 500ma, then just divide your battery capacity over 500ma.
My setup is:
750ma battery 7 cell AAA pack
500ma wall charger (9v radioshack ac adapter with the modified connector)
So 750ma/500ma = 1.5 hours of charging.
That will do you very well.
Some assumptions must be made however:
1. The voltage rating of the WALL ADAPTER/CHARGER really should match the total voltage on the battery pack. (or must be slightly higher by 1 or 2 volts, no higher. and certainly not lower.)
2. you've drained your pack to the point where the heli will no longer spin fast, but not dead. dead is bad for nimh.
I often wait for the batteries to cool after a run (probably 10 minutes after a flight) before charging them. Just buy a few packs and you'll be WELL off. Don't settle for one battery pack, trust me, I've been there and it s**ks.
Good luck
-Dan
There are many types of battery chargers out there. Depends on how much you want to spend, or how fancy you want it.
I am using the supplied wall charger, and am a Comp Engineer. The magic number is:
If your wall charger specifies say 500ma, then just divide your battery capacity over 500ma.
My setup is:
750ma battery 7 cell AAA pack
500ma wall charger (9v radioshack ac adapter with the modified connector)
So 750ma/500ma = 1.5 hours of charging.
That will do you very well.
Some assumptions must be made however:
1. The voltage rating of the WALL ADAPTER/CHARGER really should match the total voltage on the battery pack. (or must be slightly higher by 1 or 2 volts, no higher. and certainly not lower.)
2. you've drained your pack to the point where the heli will no longer spin fast, but not dead. dead is bad for nimh.
I often wait for the batteries to cool after a run (probably 10 minutes after a flight) before charging them. Just buy a few packs and you'll be WELL off. Don't settle for one battery pack, trust me, I've been there and it s**ks.
Good luck
-Dan
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RE: battery charger for smartech skylark
thanks:
the charger I have is 9V and 350 mAh, so it should take a couple of hours to charge. My battery pack is 8.4 V and 700 mAh.
However, if I measure the voltage with a voltmeter (output of the power adaptor) it indicates 13 volts, which is rather high. Thats been very confusing to me because when I have mesured other AC adaptors their voltages always seem much higher that the rating. I don't know if there is something wrong, of if the voltage will go back down when a load is applied.
guillermo
the charger I have is 9V and 350 mAh, so it should take a couple of hours to charge. My battery pack is 8.4 V and 700 mAh.
However, if I measure the voltage with a voltmeter (output of the power adaptor) it indicates 13 volts, which is rather high. Thats been very confusing to me because when I have mesured other AC adaptors their voltages always seem much higher that the rating. I don't know if there is something wrong, of if the voltage will go back down when a load is applied.
guillermo
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RE: battery charger for smartech skylark
Yes you are correct.
The measured voltage is because the "cheap" wall chargers are not designed to handle much loading, so a small load will cause the voltage to fall lower. Although the measured 13volts does seem a bit high for 9v. I can see 10.5 to 11.5 volts, but 13?
That's probably due to the lower 350 ma that it outputs. That would mean that the transformer(wall charger) has a higher impedance or resistance so a smaller shunt load (in this case the battery) will bring the voltage down.
Hope this helps,
Dan
The measured voltage is because the "cheap" wall chargers are not designed to handle much loading, so a small load will cause the voltage to fall lower. Although the measured 13volts does seem a bit high for 9v. I can see 10.5 to 11.5 volts, but 13?
That's probably due to the lower 350 ma that it outputs. That would mean that the transformer(wall charger) has a higher impedance or resistance so a smaller shunt load (in this case the battery) will bring the voltage down.
Hope this helps,
Dan
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RE: battery charger for smartech skylark
thanks:
I checked the voltage again while the battery was connected and measured 10.7 volts, which seems a little more reasonable.
any suggestions to buy a smarter charger for that battery?
thanks
guillermo
I checked the voltage again while the battery was connected and measured 10.7 volts, which seems a little more reasonable.
any suggestions to buy a smarter charger for that battery?
thanks
guillermo