either ones a good controller though.(no wrong way to go)

Hmm u might be right :) i will overthink it once again. Thx for ur effor to bring me on the right path :)

I agree, the 9920 is a better controller choice. the xl1200 could be run on 20 cells with the 7018 controller, though, which would be pretty silly in the power department! All The Lehner basic xl motors are capable of the same power output, but the slower turning motors make the power with voltage as opposed to amperage. Personally, I would run the xl2000 motor. It will have excellent runtime, as well as the ability to easily achieve your speed goals and could take some additional voltage if you want to push the envelope. The xl1200 is a great choice for higher voltages (25 volts or so would likely be the sweet spot for the xl1200, while 17 or so volts would be the sweet spot for the xl2000).

Why is it refered to as a 9920 and a 9918? I'm guessing your just rounding the numbers up?

9920=99 amps at 20 cells
9918=99 amps at 18 cells

The controllers were recenlty re-labeled to 9920, reflecting some testing and the controllers proven abilty to hanlde 20 cells. The recent controllers have a 9920 label as well as double wires for the motor and battery connections.

So is the 9918 on your site actually a 9920? Which can now handle 20 cells?

I changed the name on my sight to reflect the new labels(9920 is listed on my site instead of the 9918). If you have a 9918, it can handle 20 cells.

Rannick, I would go for the 9920, too.

BTW, I also got it confirmed from BK that this 18/20 thing is just a name change. Perfectly identical electronic components, that's what I was told.

DAF

Yes, the same goes for the 18120, it has become 20120 and the 30120/30150 became 36120/36150.

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...