mat_koski

Quick question!

I have a Tanic Li Po pack from a few months ago. It doesnt specify its mAh. The only details it has on it are...

"10-12 C high discharge"

Its a three cell, 11.1 v.

Charge at 1 C max.

While im here, would someone mind giving me a quick refresher on the meaning of the 'C' symbol as stated above?

Thank you.

CanDo

Hi Mat. Here is what I know. "C" is the capacity of the battery. If you had a 1Ah battery pack and you charged it at 1C, you would be charging at 1 amp. If you charged it at 1/2 C, it would be charging at 1/2 amp, 2C is 2 amps, etc. If the pack was discharged at 12C, it would be discharging at 12 amps. The number in front is just the multiplier.

guver

My Feedback: (325)

The missing number is C unfortunately. Without the capacity the multipliers are meaningless, right?

Anyways if you give the dimensions one should be able to get you close by researching on website. After that the pack can be tested by charging/discharging and labeled.

CanDo

Right, I just answered the second question. The "C" is important! I agree, the only way I know to get the capacity is to cycle the battery and measure the capacity.

mat_koski

Alright! I remember that capacity bit now!

I have the dimensions of it right here... Length= 2 inches Width= 1 and 1/4 Height = 3/4 inches.
Again, its a Tanic battery.

More questions!

My charger has three battery charging settings... 250mah, 500mah or 1000mah. I have used the 1000 before. The issues i am having with this battery is that my speed controller cuts it off when i go full throttle very shortly into flight. Its voltage drops too low under a load.

Also, how can i measure the capacity by cycling it?

Whats the max voltage for a fully charged 3 cell li poly? I know the minimum is 9 V.

I have more but i have forgotten them.

jdetray

A fully charged lipo is 4.2V per cell, or 12.6V for a 3-cell pack.

- Jeff

Dr Kiwi

That's got to be a small capacity pack... I have a 3s 10-12C Tanic 1550 pack in front of me and it is 2 3/4"L x 1 3/4"W x 3/4"D. (3.6 cubic inches!)

Maybe yours (1.5 cubic inches - less than half the volume) is only 850mAh or even less. Even a 900mAh TP pack is bigger than yours (1.76 cubic inches).

If it is indeed ~850mAh you can only expect to draw 8.5A or so! That may be why you are hitting LVC so quickly - what current does your motor draw?