strange bl controller

[t-maxxracer32]

http://www.aero-nuts.com/product_inf...roducts_id=399

thought it was weird that it can handle 12s lipo but only 80 amps...

are we talking about using 10C lipos or something?

thanks!

[lincpimp]

By 12s it means that it can handle 12 lipo cells in series. 12x3.7=44.4volts. 80amps is its continuous rating. 80amps x 44.4volts = 3552 watts or 4.7 horsepower. Thats a lot of power! Keep in mind that the rating I arrived at does not account for losses due to effecientcy ratings, it will be lower than 3500 watts.

[t-maxxracer32]

ooooooooo i thought that the batteries put out amps. like if it was a 6s batterie it would peek at like 100A or something! i have no idea how any of this works!

[lincpimp]

Ok, Lipos are rated a few ways. 2s,3s,etc - means how many cells in series. 2s = 7.4v, 3s = 11.1v, etc. They also have a mah rating, 2000, 3000, 4000, etc. That is Milliamp/hours, divide by 1000 to get amp/hours. The C rating indicated the battery's output ability (amps). To figure out the output, miltiply the amp/hour rating of the batteries times the C rating. For example you have a 20C rated 3000mah pack. 3000mah =3ahx20c=60amps. Usuually the C rating refers to the continous discharge ability of the battery, not the burst rating. That is why you see batts rated as 20c/30c, the second is the burst rating. Hope this helps, you needto know this when selecting a lipo, so you do not overdischarge it(puff or fire)!

[t-maxxracer32]

well i knew the first line! lol

thanks alot for the help! that really explained it very well.

so you couldnt really use much more than a 4ah 20c pack with that controller correct?

so if its a 12s 4ah 20c pack it would be just the same as a 3s 4ah 20c pack? as far as how much amps it puts out?

[lincpimp]

Correct, it does not matter how many cells in the pack, the C rating will determine how many amps the pack can output. Now the motor and gearing will determine how many amps the system can pull, not the batteries capability to provide those amps. That is why batteries usually puff, from being over discharged. Say you have a system that pulls 80 amps and you try to run it with that 3000mah 20c lipo. The lipo can only keep up with 60 amp draw and the system pulls it to 80amps. That would be ok for a short time (a second or two) as most lipos have a short "peak" rating that lets them handle short current spikes. However if that 80 amps draw was there most of the time the battery would most likely puff. I generally try to have my lipo capable of producing about 20% more than I need. If I figure my system wil pull 80amps, then I would want a 100amp lipo, 5000mah 20c for example. Always good to have a little cushion!

[t-maxxracer32]

and you can tell how many amps your motor pulls by...?

thanks for all the info? idc about the controller anymor!

[lincpimp]

That is the fun part. Usually the motor is rated with a max amp draw number. This is the number that I usually add 20% to and find a lipo that is similar to that figure. Not guaranteed, cause some motors can be geared to pull at or more than their max rating. Also if too high gearing is used it can create alot of heat in the motor and esc which can draw more amps from the battery. This is why it is good to gear low when testing a new setuo, and to use an already tested setup, like most of the guys here use. Saves time ad money using an "established" setup.