My CRT.5EXT...;)

[MetalMan]

If you could find a motor like a Feigao 12L or something like that, then you could lower your amp draw on 4s.

The problem with changing gearing to maintain the same top speed when increasing voltage with the same motor is that the motor's resistance is still the same. V = IR, and so since the resistance (R) is the same, when volts (V) increases, so does current (I).
Changing the gearing just means the motor won't pull as much current as if you kept the same gearing when increasing the voltage, but since it's still the same motor, the motor is capable of pulling more current.

[GO-RIDE.com]

Cemetarygates,

What are the handling differences btwn the stock chassis and extended RCM chassis? Did you have to change any of the suspension set ups?

I just rcvd the RCM chassis, but will not have time to build it up for a couple of weeks.

[starscream]

You will indeed lower current by both increasing voltage AND lowering the gearing. You will also increase the potential amp draw by increasing the voltage. This is why you may see high amp spikes

What you should be looking at is the average amps not the amp spikes. You may see a 91amp spike but your average amp draw should have decreased in comparison to the 3S setup with appropriate gearing.

For instance, I have recorded an average of 40amps with 8S A123 and an average of 35amps running 10S A123's with appropriate* gearing

It looks like you had an average amp draw of 8.38 amps. I would guestimate that 3S would increase the avg amps to ~ 12+ amps

I would be interested to see what you record with a 3S setup with appropriate gearing.

* appropriate gearing is the gear ratio required to meet the same speed at any given voltage

Originally Posted by GO-RIDE.com

Cemetarygates,

What are the handling differences btwn the stock chassis and extended RCM chassis? Did you have to change any of the suspension set ups?

I just rcvd the RCM chassis, but will not have time to build it up for a couple of weeks.

well, with the new chassis I can push much harder into the turns without flipping the truck. I also put some HPI MT firm springs in the rear.

Originally Posted by starscream

You will indeed lower current by both increasing voltage AND lowering the gearing. You will also increase the potential amp draw by increasing the voltage. This is why you may see high amp spikes

What you should be looking at is the average amps not the amp spikes. You may see a 91amp spike but your average amp draw should have decreased in comparison to the 3S setup with appropriate gearing.

For instance, I have recorded an average of 40amps with 8S A123 and an average of 35amps running 10S A123's with appropriate* gearing

It looks like you had an average amp draw of 8.38 amps. I would guestimate that 3S would increase the avg amps to ~ 12+ amps

I would be interested to see what you record with a 3S setup with appropriate gearing.

* appropriate gearing is the gear ratio required to meet the same speed at any given voltage

Heres the info:

3s w/10L = 13.13amps avg.
4s w/10L = 8.38 amps avg.
4s w/9xl = 12.10 amps avg.

So, is it safe to run the truck with the 9xl(100A spikes) and not harm the battery? Thanks for all you help everyone!

Bye

[starscream]

Originally Posted by cemetery gates

well, with the new chassis I can push much harder into the turns without flipping the truck. I also put some HPI MT firm springs in the rear.

Heres the info:

3s w/10L = 13.13amps avg.
4s w/10L = 8.38 amps avg.
4s w/9xl = 12.10 amps avg.

So, is it safe to run the truck with the 9xl(100A spikes) and not harm the battery? Thanks for all you help everyone!

Bye

Well, if you overheat teh pack you could damage it or it could catch on fire. You should not let a Lipo pack's temp go over 140deg F.

I think 100AMP burst is the probably reaching the limits of 15C cells but I do not know for sure. This is a question you should pose to the manufacturer so you get a definitive answer.

Originally Posted by starscream

Well, if you overheat teh pack you could damage it or it could catch on fire. You should not let a Lipo pack's temp go over 140deg F.

I think 100AMP burst is the probably reaching the limits of 15C cells but I do not know for sure. This is a question you should pose to the manufacturer so you get a definitive answer.

Thanks for your answer, I'll call Dan @Truerc soon. BTW my pack only heats up to around 95F, motor is at 140F, and the esc is at 135F.