Safe 2 Cell mod

[rmyc]

this is my 2 cell mod.... it uses the second cell only when going forward( it could be change for revese or both)
the idea was not to hype up the bit-chip to 3v but only the motor
soo if some thing burn it would be the motor, and not the chip

E.E. , if there is any thing wrong with this , holla!!

thanks

[rmyc]

in froward

[rmyc]

in reverse

[john]

that's very interesting, and if it works would come in very handy. I have 2 questions:

Did you try it yet or is this just an idea you came up with?

Is there an easy way to charge the 2nd cell?

This could be a really sweet way to handle a 2 cell mod. I'll be watching this one intently! I don't see any reason why it wouldn't work, other than you're sending a different charge in series through the 2nd batt, but I'd think that it could take it.

[Bunta]

Hi rmyc!

I like your idea it is creative.

I have one question for ya,, how do you propose to charge the 2nd battery after it's discharged?

I think that the PCBs can handle a paltry 2.4 volts,, I've heard of some mad scientist who have used 9v and 12v!

good luck and keep coming up with them mods!

-Bunta out

[Dayfall]

Don't forget about the voltage drop across the diodes. I am not an EE mojor, but I have read that there is a 0.7v loss from the average diode. The transistors that run the motor loose about 0.2v each. I think a better way to do it is to find the power leads to the PNP transistors (and their pullup resistors), cut those leads, and run your 3v to them.

[rmyc]

Originally posted by john
Did you try it yet or is this just an idea you came up with?

well actually i havent tried it on my bit yet..
..i tried it on another motor and it work fine
i'll probably try it on my bit some time soon, but I DONT KNOW HOW TO SOLDER....lol
..as soon as i learn how to solder i'll do it, or i'll ask a friend.

[rmyc]

Charging

Charging hmmm....i haven't thought about it yet
...well cause they aren't really linked up. you could SOME HOW link them up paralell and double chage em with the stock charger

i'll figure it out sometime , someday

[Namuna]

..

[john]

What if both batteries where connected in parallel in addition to what you are talking about, but there was a switch to break the connection to the second cell for when it's running?

Wouldn't that effectively let you flip the switch to connect the positive terminals in parallel to charge it, and disconnect the positive terminals (with the switch) when you run it?

[NorCalCoug]

I've run 6 volts with no issues and flirted with a 12v garage door opener battery for a little bit. No motors burnt out yet, no bits burnt out yet.

[GT-ahh]

when you connect batteries in parallel it doubles the current not the voltage, so the motor would only be getting 1.5v or whatever.
and also you have to completely flatten both batteries in order to charge them or you get a memory effect, and as both batteries wont go flat at the same time this will be difficult.
btw, has anyone actually fried a circuit or motor from a dual cell mod?

[GT-ahh]

sorry to double post but just reviewing your schematic it does not look viable because the second battery has to be earthed to pump voltage into the motor and when you press forward the bit-chip pumps voltage out where youve got the 2nd battery should be earthed. you might even overload the circuit and then youve got one expensive fridge magnet....

[rmyc]

Originally posted by john
What if both batteries where connected in parallel in addition to what you are talking about, but there was a switch to break the connection to the second cell for when it's running?

Wouldn't that effectively let you flip the switch to connect the positive terminals in parallel to charge it, and disconnect the positive terminals (with the switch) when you run it?

yah that's what i thought about ...

[rmyc]

Originally posted by Namuna
..

Thanks y'all..it's a big honer for me to be moved to BIT Science.
*sob**sob*

Thanks