# Batteries, charging and where do babies come from?



## fluke (Feb 27, 2001)

OK.....for a project I'm working on ...I'm using the battery from a cheap 40.00 air hog style 2 channel Helo. 

The battery count in the original Helo's controller is 6 AA's at 9V. Does that mean when charging the little battery is simply getting straight 9V DC going right into the battery *or *is it altered electronically for OHM's, resistance etc etc???

In other words ...Can I run 9 volts right into that sucka and be ok?

OH YEAH....scratch the baby thing....I just got the Mommy Bear and Daddy Bear talk from my Daughter.

Thank ya kindly!


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## 4ThePinkRacing (Apr 30, 2010)

1 battery is 1.5 volts .. chrage one battery at 1.5 volts .. set to MHA of battery .. 

6 abtterys chrage at total volts and set to MHA for one nbattery say if there all 2500 then set to 2500 ..


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## fluke (Feb 27, 2001)

I usually am pretty good with basic electrical and stuff...but...can you or someone clarify that one up a bit? 

Thanks! 

OH...and let ME clarify:

The battery count in the original Helo's controller UNIT is *6 AA's* at *9V total*. Does that mean when charging the battery is it simply getting a *straight 9V DC* right into the battery directly? or is it altered electronically for OHM's, resistance etc etc???

*In other words ...Can I run 9 volts DC right into that small batterry from the air hog style Helicopter and be ok??*


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## OvalmanPA (Mar 21, 2000)

I would say you are typically charging by amperage and not voltage. A pack of NiCd/NiMh AAs is normally safely charged at 1.5 - 2 amps until peaked. 

The way I'm reading your post however I'm not quite sure if you are trying to charge the battery or if you are talking about the voltage being delivered to the motor on the Air Hog helicopter?? If you are talking about the latter you'd probably almost have to measure the voltage being delivered to the motor and see if they have it metered in some way from 9V to something lower.


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## fluke (Feb 27, 2001)

Just trying to charge the Battery. 

There are no markings on the battery at all.


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## OvalmanPA (Mar 21, 2000)

If you are sure it is a 6 cell NiCd/NiMh then I would give it a go as I described above. What kind of charger are you using btw? I'd set the voltage threshold (cutoff) fairly low at like .02-.03 and monitor the temperature. My only thought on this is that it is unusual for NiCd/NiMh cells to have 1.5v.


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## fluke (Feb 27, 2001)

I think this has gone a step or two too complicated.

The battery is just a tiny, simple square thing taken from a cheap MICRO / MINI 2 channel helicopter.

The 'original' charger combo / controller for that 'same helicopter' has a tether line for charging that helicopter. 

Now that my tools are home from work I can measure the voltage coming from that tether. 

I'm still curious if 'that' voltage is altered in any way.....OR.....is it really as simple as 3.0V.....4.5V ....6.0V....9.0V......etc etc.

I should have been more clear me thinks.

Has anyone ever flown that small Chinook? by Syma Its amazing! My girlfriend bought it for me on line thinking it was the 16" version ....but dang! it fly's very well and a decent flight time too.


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## 4ThePinkRacing (Apr 30, 2010)

fly this one .... lol flys nice to its a 400 size heli .. B400 .. by blade


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## ta_man (Apr 10, 2005)

fluke said:


> I think this has gone a step or two too complicated.
> 
> The battery is just a tiny, simple square thing taken from a cheap MICRO / MINI 2 channel helicopter.
> 
> ...


I think the issue you face is that to charge a battery you have to have a way of limiting current (and stopping when the battery is charged), not just applying a particular voltage. If the voltage source has too much current capacity, you could damage the battery. Also if you don't stop feeding in current once the battery is fully charged, you would again damage the battery.

Say the battery is partially discharged and is at 8.5V. You connect a 9V power source to it. You have 0.5V differential. If the battery internal resistance is 100 milliohms (0.1 ohm) that 0.5V different will potentially push 5 Amps through the battery. (I=V/R ... 0.5/.1 = 5Amps).

Now if you are using a wall wart type voltage source you could probably find one that only has, lets say, a 1A output, so it couldn't put out 5A into the battery. But the problem with the wall warts is the peak voltage is usally much higher than the rated voltage. A 9V rated wall wart typically has an unloaded voltage of 13-14V. So that means it is not going to stop putting current into the battery once the battery reached 9V. Unless you are sitting there looking at the voltage with a meter you could overcharge and damage the battery.


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## Watchman (May 19, 2009)

From what I have read in this post, you appear to charge the receiver" pack from the transmitter (9v). As far as charging away from the transmitter, you need to know the voltage of the "receiver" pack. Knowing the pack's voltage you can determine if the pack is NiMh/NiCd or LiPo. That will determine the charger you require for charging away from the transmitter. 

Most likely the transmitter has a built in inexpensive voltage regulator. This is usually in the form a "chip" and limits the charge current and the output voltage.


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## 440s-4ever (Feb 23, 2010)

Yes, you just feed it 9v. Or 10.


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## fluke (Feb 27, 2001)

*Thanks gents! *

I'm better with LED's....and Sci-Fi Scale Models. 

I'm making a Johnny Lighting small di-cast 'Lost in Space Chariot' Radio Controlled CHARIOT and to prove how nuts I am after I did this:





*Lets put it this way...lets see if I have this straight.

The battery that I am using is from a small 40.00 dollar Helo and I'm using 'its' transmitter with a pull out tether to charge the same battery. 

Should the 'Transmitter' have the AUTO CUT OFF built in? 

Thanks! and the the pic below is what I rough radio gear & material I have so far.*


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## fluke (Feb 27, 2001)

Good news!

The little car that I am using the receiving and transmitting radio gear from is 'RADIO' and not infrared so brigh light and day light play will not be a problem....COOL!

The other good news is that I am converting radio control transmitter from the 'MicroSizzers' car to fit the inside of the larger HELO controller so I can still use the 'safer' and original charging system and all I need to do is re-arrange the* L*eft - *R*ight to the other side for Forward and Reverse controls. The left and right will be Chariot's light controls and in the controller....the robot sounds from a key chain collectible of the B-9 Robot "This does not Compute" and three other B-9 phrases.


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