[Carlyle]

Hello everyone!

I'm a airplane guy, and have just baught my first helicopter which is on its way to my door right now. My question is this. Can I charge a 2100 mah battery with a regular charger? I know if I can it would take much longer, but can I even do this?

I have a futaba charger that came with my 6exap TX. the charger charges at 4.8V 100 ma.

If anyone knows this, please help me out.

Thanks lots!

Carlyle

[Nuker]

The answer is yes it would work.

-edited so as not to cause confusion

Bob

[Wayne MIller]

Hi,

My understanding is that to charge a NiMh or NiCd battery, you have to put in 1.5 timers as much as it is rated at, that is from a discharge state.

Therefore, to charge a 2100 pack with 100mah charger would take:
Total ma needed is 2100 X 1.5 or 3150ma
Your charger supplies 100ma, therefore it would take 31.5 hours.

If your battery is partially charged, it would take less.

The following is a list of battery voltages as a reference.

Reciever
4 cell 4.8 v pack with 240mah load. Full charge = 5.4 volts (1.35 volts per cell).
For safety do not fly below 4.8v – 1.2 volts per cell
5 cell 6.0 v Pack with 300mah load. Full charge = 6.75 volts (1.35 volts per cell).
For safety do not fly below 6.0v – 1.2 volts per cell

Transmitter
8 cell 9.6 v pack with 400mah load. Full charge = 10.8 volts (1.35 volts per cell)
For safety do not fly below 9.4v – 1.175 volts per cell

Battery Info
http://www.rcbatteryclinic.com

Hope this helps.

Fly4Fun,

Wayne Miller

[Carlyle]

Thanks for the super quick responses guys!

Its good to know I dont have to buy a new charger! haha.

This battery/power thing really gets me some times. I cant seam to figure it out.

Thanks again

Carlyle

[Nuker]

Wayne,

you got me to thinking. The 50 Mah charger for the 600 Mah battery that comes with the radio, indicates a 16 hour initial charge is recommended (ok 2 hours short of your calc but it makes sense)

To be honest my understanding of C/10 charge was dividing the mah by 10 and charging for 10 hours at that rate.

Never to old to learn

Bob

ps I edited my post so as not to confuse the issue

[airframe]

Yes you can but why would you want too? When you charge a batt with a charger that isn't made for it do you really know that it is fully charged? Do you really want to risk your new heli trying to save a few bucks. Peak chargers are pretty cheap these days (less than $100) buy one and then you know you have a fully charged batt when you go flying.

Mike Sebastien

[Wayne MIller]

Hi,

I just want to clarify that what I previously said only applies to NiCd and NiMh batteries. It does NOT apply to any lithium (LiPo's etc.) batteries - they take a special charger.

Airframe was correct, you can get some pretty good chargers for a fairly low price. Example the Quick Field Charger MKII for $65 Canadian at Great Hobbies. It will charge two different batteries at once and is a "quick" charger It will charge NiCd, NiMh, and LiPo's. The only disadvantage is that it must be plugged into a 12VDC source (car cigarette lighter etc.).

I put together an article for Model Aircraft Proving grounds explaining the the Quick Field Charger MKII and what "C" means - you may want to take a look. It's here:
http://www.geistware.com/rcmodeling/...ry_charger.htm

Hope this helps.

See ya at the KW Scale Rally second weekend in Sept.!

Fly4Fun,

Wayne Miller

[rcjetguy]

I would really suggest a good voltmeter that can check the battery's voltage under a load (300-500 ma) is the first thing to buy. This will tell you, reliably, if your batteries are safe to fly. Then you will be able to see for sure whether your low output charger will do the job or not. It will definitely put charge into the batteries but I don't think it would charge them to full peak capacity. At least with a load applying voltmeter you will know for sure whether you can safely fly or not. The most expensive charger available will not tell you this valuable information!
Rcjetguy