Originally Posted by
morph999
Pingbattery used to be a lot better. Some of his newer batteries have had some problems. Not sure why. The Thundersky's are better batteries in my opinion. People seem to be having a lot of trouble with the ping BMS's.
The thing is that a lot of those ebay batteries are factory rejects I think. I don't have proof but how are they providing these batteries for so cheap. I think pingbattery.com might be also using factory rejects but he probably is better on the inspection but lately, I think he's been letting some bad ones through.
Following your suggestion, I will order the 2806 Nine Continent. It comes with plug-in Cycle Analyst, which I was planning to buy anyway. As you mentioned, they also have a 2 year warranty, and their shipping to me (or back to them) is really cheap (I am in Canada). I am also taking you advise of sticking with the 25A controller - I just want it to work and not get into a race!! :-)
The last decision I have to make is the battery. I am sticking with 36V, but have not decided to aim for 20Ah or 30Ah. Checked all the sites you had mentioned and more. Ping prices are the most reasonable for the buck (for LiFePO4); but your last post doesn't give them the highest marks. I actually considering using SLA batteries. They are heavier, have a shorter life span and discharge rate; but I can pick them from local stores here; and they are relatively inexpensive. I also came across a rather interesting solution:
http://www.youtube.com/watch?v=zKKvP9wWrlY&feature=fvw
Someone had used 36 volt Dewalt battery packs, which he claimed give him 20Ah. They are relatively cheap (Amazon selling them for $170 each). They are Li, and come with 1-2 year warranty. If it works, they are also very light.
I also currently have a 36V, 12Ah LiFePO4 battery (only used for a month). Not sure if it is the problem with the battery or the controller (even might be the motor itself); but after couple of weeks of working fine, it does cut out on me. I will try out with the NC 2806 kit to see if it is working. Talking to at least 3 different stores yesterday, including ebike.ca people, it seems as you can use almost any size Ah battery. It just may last shorter (or longer). Also, if your controller draws too much, and you have a low C battery; I guess the battery BMS will cut out the power. (I wonder if that is the case with my current 20Ah Cylte controller?)