danlrc

Searched forum, but couldn't find definitive answer.
Can I use 7 x 1.2V (8.4V) NiMH's instead of 6 x 1.2v (7.2V) with the Tam electronics?
The obvious easy answer is no, but has anybody done it?
Have really efficient Faulhaber motors, but too slow at nominal 7.2V. The motor max amps are lower than any of the can motors typically used.
Want to use the motors in a Pershing build. Larger pinion is an option, but want to keep the power with higher motor RPM range.
Thanks.

At max charge, 6-pack would close to 9V. The 7-pack would be near 10.5V, only 1.5V higher.

tomhugill

I think will cooling up to 12v is possible. However I think an 8.4v pack would be fine.

MAUS45

I know that there is a Tanker in the UK that replaced the stock electronics in his 21st Century 1/6 Stuart with Tamiya's Sherman DMD and MF units. He did modify the DMD to use a cooling fan to support a 12v battery as a power supply.

TheBennyB

Willy has tested the tamiya DMD up to 14V before it kicked out. I've seen plenty of people use 8.4V and even 3S lipo's, and as stated lots of people
use them in the Stuart running 12V.

Rustytrax

The Pershing is darn fast out of the box. A 7.4 20c lipo is all I would do, because it would be well beyond scale speed with more juice.

Elwarpo

I have run 7cell NiMH and 2S lipos without any issues.

dtslmberne

it would be well beyond scale speed with more juice.

ausf

I use 2 cell lipo with both ElMod and Spektrum systems that were intended for 7.2, so I wouldn't worry about Tamiya, they tend to over engineer stuff. That said, I'd stay away from going to 3 cell or anything higher than 9 volts, even if it seems to handle it, over time you may be taxing some components, especially the caps in the flash unit.

danlrc

Thanks for all the answers. Sounds like a 7 cell NiMH pack will be fine.
Note that the motors I'm using are slower than the motors normally used. That's why I want to try higher voltage. The higher V range and the largest pinion set I have should give scale speed.
As I build this winter, I'll post the motor/gearbox/battery info.

heavyaslead

Higher battery voltage does not mean faster speed.

These electronics have voltage regulators built in so the battery voltage is reduced before any motor controls are processed.

I use 8.4 V in the Leopard and King Hauler models with no issues (and no faster motors either).

danlrc

Eric,
Thanks for this info.... new to me. So the Tamiya ESC circuit output maxes out at some specific V no matter the input V? Bummer for the motors I wanted to use.
I have a programmable Tx and can set throttle output greater than 100%. Would that push the Tamiya ESC V output?
Thanks,
Dan

ausf

But this amp goes to eleven...

heavyaslead

Any one who is a musician is required to pay homage to Spinal Tap!

Oh, and Nigel just grab one of those sandwiches LOL

heavyaslead

Stick will only recalibrate the range not the total Voltage output.

danlrc

Scott
Sorry if I seem a bit dense here...

Assume V range of battery is 8V fully charged and drops to, say, 6.6V during an operating session. Does the Tamiya ESC provide a constant regulated voltage range, eg 0V at zero throttle to 6V (or some constant max voltage) at full throttle?

Is the Tamiya output V max known?

Can the Tamiya board be calibrated in any way to increase the V max value the motors get?

Thanks.

Alan123

I have been using 11.1v 3 cell lipos in some of my tanks and they ran fine and it was nice having so much power in such a small square battery unit.

The small size helped reduce wire snag problem inside on the turret turn.

More lately though I have noticed that 2 tanks have developed recoil problems and I think that it is possible that the higher voltage over time has damaged the recoil function somehow. So be careful.

I was googling for help and this was the only info that came up and being a member I thought I would add my experience with higher voltage and Tamiya DMDs to the body of knowledge.

Cheers

Alan

MAUS45

Thanks Alan for adding your input!!! I have bee thing of adding the Tamiya electronics to a 1/8 scale Tiger II I have.