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Finnster
KillaHurtz
 
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Posts: 2,958
Join Date: Apr 2006
Location: Bucks Co, PA
10.26.2007, 04:24 PM

Quote:
Originally Posted by johnrobholmes View Post
Another point to consider, what is a true 20C pack? I see many graphs of a 2200mah 20C pack that doesn't hold 2200mah at the said discharge rate. The mah of the pack is usually derived from a 1C discharge. What is the cutoff voltage of the test too? There are no clearly defined rules for the variables tested, and average voltage isn't given for the discharge rate either.

Well discharge capacity does depend on the discharge rate, that's no secret. Ie higher discharge = lower capacity. In all fairness, there are not any std rules in rating batt packs. Its kinda like cars and HP, up to a certain point you can prolly get away w/ saying anything, b/c test condits are so variable, & if you lowball it people w/ just buy the other guy's car.

Generally tho I've seen 3.5V/cell as the limit to discharge rate. IOW, a 2S1P 2.1AH 20C batt should hold 7V @ 42A continuously. If its doing 6.5V, its not 20C

The nice thing about MA is they do have std size lipos (44mm wide) and in a large range of caps. TRC's tend to be 50mm and don't fit in NIMH batt trays. They are much more affordable than FPs tho too.
   
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