I agree with Mike. I'm running a 2000XL/7020 on 18cells. With it geared at 16/72, it is very fast and hideously torquey. Think I need to gear up a bit - gonna try 18/72, or maybe 16/66.:cool:

Nice, how long does it take to charge 18 cells? Or is it just the same as charging 14?

I'm using the ripmax, supernova charger. It can charge upto 25cells at upto 5amps. I charge my 3300 and 3.3A (1C), and it usually takes about 1h10m - the packs take about 3550mah, not 3300mah! Cooling down before running takes about an 1 hour.

I have the Triton, does 24 cells, I can do my 14 cells in 40minutes @ 5A, they also read at 3500mAh.

So I guess it takes longer the more cells you have.

not necessarily. I charge at only 3.3A, you charge at 5A. Problem with mine is my power supply is only rated for 10A 12V = 140 watts. Charging 21.6v at 5A = 108watts at say 70% efficiency = 154watts. Thats a bit too much for the power supply IMO, so I only charge at 3.3A - and the power supply still gets pretty warm.

Anyway, charging at a higher current means the batteries will get hotter and take longer to cool down. SO the time saved in charging is lost in waiting for the batts to cool...

I run my batteries right off the charger (more punch).

I always thought you had to let the packs cool down after charging.....ohwell, I'll try that next time I run. Cheers

The reason batteries are hot after charging is because of the amount of current pushed to them by the charger, especially at higher amps (5-6). The batteries have to dissipate the energy by releasing heat. Once you start using the batteries, the excess energy is immediately released by the discharge of using them.
If you have a charger that discharges/cycles batteries, try charging them, then immediately discharging at about 5-10 amps. You'll see the temps drop almost immediately and they will stay cooler through the entire discharge.
The reason batteries can be hot after running them is the high current we discharge them at. When we discharge batteries at 30, 40, 50+ amps they have to struggle to keep up. If we only ran GP3300 (or any other high-quality battery) at 5-10 amps, they would never heat up. They barely get above ambient temperatures at 20 amps.

This is why you should always let your packs cool after running, but you get the best punch if you run immediately after charging. The heat is there for differing reasons in both cases, so it should be treated differently for both.

I'm sure there are plenty of technical descriptions and graphs, etc.. that can be used to go along with this, but this is a simple enough explanation, I hope :)

Yeh, I understand now. Thanks for your explanation batfish - it makes sense. Definately gonna try that next time....:)