RC India

RC Equipments => Batteries and Chargers => Topic started by: abhay on February 26, 2011, 12:31:21 AM



Title: How to charge 110mah lipo weighing 3 gm.
Post by: abhay on February 26, 2011, 12:31:21 AM
Hello Everyone.

i have obtained lipo batteries for a robotics competition.
Specifications:
Lipo
Volts=3.7 v
Current=110 mah
Weight=3 gms approx.    I have obtained these from i pod.

i need some alternative circuits to charge these batteries. Such batteries are not common in scale flying. I m planning to make a dragonfly(scale 1:1), so im in search of a micro rx as well.

Thanks,

Regards,
Abhay Singh


Title: Re: How to charge 110mah lipo weighing 3 gm.
Post by: akky on February 26, 2011, 12:41:36 AM
you should have bought these batteries from hobby king instead of performing surgeries on your mp3 player  :o


Title: Re: How to charge 110mah lipo weighing 3 gm.
Post by: abhay on February 26, 2011, 01:01:10 AM
i have obtained these ipods from friends today, these i pods not were not working anymore. two had RnDs already done with,and are no more repairable. battery are still woking.
The third one has got a replacement battery, which has been recently replaced under warranty.But I-pod stopped working the fourth day warranty got over  :banghead: .

However i have seen the power of such batteries, and had flown a non rc electric glider using pager motor, which never came back to me.


Title: Re: How to charge 110mah lipo weighing 3 gm.
Post by: KALYANPRODHAN on February 26, 2011, 06:18:22 AM
This LiPOs are sold in Electronics Spare shop @ 100/- to 150/-. 200mAh LiIon cells are sold @Rs45/-. This rates are from Chandni Chowk and you may can get with some extra cost from your nearest TV/Radio mechanics shop. They are have the protection circuit builtins. PM me your address and I can send you a small of such circuit PCB complete and you then can use any charger that will save you from overcharging. Better always keep multimeter which I Prefer.

Just use a mobile charger with 100 Ohm resistance in series.(1/4 Watt) Check the Polarity please.
You may use 100Ohm(1/2 watt) resistance series from 6 Volt Lead-Acid Battery for competition site charger.


Title: Re: How to charge 110mah lipo weighing 3 gm.
Post by: abhay on February 26, 2011, 10:41:32 AM
thanks kalyan Sir,
I have tried to obtain such batteries from local electronics spare shops, but they owe the batteries with hard metallic casing, as a result, the weight is much more. I have even tried to use rechargeable button cells(called Lithium ion batteries) used in bluetooth earpiece, but power to weight ratio is not appropriate,due to casing.
I have found such batteries Only on I-pod repair shops at "Naka-Hindola" Lucknow.
Yes they charge Rs 120 for replacement.

Kalyan sir, i have tried to charge the battery adding 60 ohms( 3/4 watts ) resistor in series with Nokia charger Rating output= 5v, 890mah. But discontinued due to fear of overcharge, as battery showed little heating.
I have multimeter as well, but was lacking resistors, and experts advice. I have exploded two lithium batteries since past three years and dont any futher want that smell. My family will definitely throw me out.
Sir I m PM ing my address.

Let me make it Bright that Im planning to make a 1:1 dragonfly,so materials has to be as light as possible. RnDs started.


Title: Re: How to charge 110mah lipo weighing 3 gm.
Post by: abhay on February 26, 2011, 11:01:21 AM
Sir before you send me the PCB, i want further help.
I m confused whether to use actuator or a mobile vibrator for flapping if wings. If actuator, then, i need circuit diagramme for a light weight alternator circuit.