I have two Pulse LiPo batteries that are a little bit out of whack. They're 10000 mAh 6S batteries, and when I run them on a regular charge cycle, I noticed that they take a very long time. And when I dig into the Hyperion menus and show the individual cell voltages, both batteries are nearly the same situation: 5 of the 6 cells read 4.20V (perfect) 1 of the 6 cells reads 4.14-4.16V (1-2% low...not the same cell in these two batteries) The internal resistance numbers are comparable to all my other batteries Now that might strike you as a little OCD that I would care, but that's how meticulous I am. I've flown these batteries, but I usually use them for the first flight of the day, and I generally only take them to 50% or less of their capacity. I always fly two batteries in parallel. This does not seem to be an issue with my charger(s). I have 4 other pairs of similar batteries (Pulse and Tattu) and they all charge perfectly. And I have two chargers and this happens with both chargers. So here's my question: what should I do with them? Please answer the poll and add comments if you'd like.
Steve: You don't say whether this disparity between the cell voltages is a new phenomenon for these particular batteries or not. If it is a new phenomenon, the cells are telegraphing the future to you. If not, then that's just the way they are. They might have been like that since the day you bought them. In other words, it's hard to say what to do without the historical context. Andy.
Interesting you say that. These two batteries were "born that way". I noticed it right away, and the reseller refused to exchange them, saying "it was within acceptable tolerances".
I like option "E" Sell them to an unsuspecting newbie. hahaha Steve I would just would use them with caution.
As an air traffic controller might say, "resume own navigation." Meaning: proceed at your own discretion. If they were in this state when you first got them then adopt a "distrust and verify" approach.... Andy.
Steve IMO, the proof is their performance. I would do a test flight with them and monitor flight time versus power consumed and if they are in the same exact range as the other batteries I would say they are good to. See if the battery voltage drops sooner than normal. See if the battery voltage drops to 21.6 with a lower power consumed. I usually start seeing 21.6 when I have consumed about 15,000 mah consumed with 2 QC 10,000 batteries. I usually land with 21.2 to 21.4 volts and 16,500 mah consumed.
This was a little bit of a skewed data set because I actually flew 5 different flights (5 take offs and landings) with this one set of batteries, totaling 12.5 minutes. According to the GPX files, I used up about 13,600 mAh, and I did hit a low of 21.1V a couple times on the last flight when I deliberately did an aggressive climb-out (over 100A). I'll reserve judgement until I run these through a recharge for a more accurate assessment of the current they gave up. But they seemed to perform acceptably.
I have a computer battery tester, but it "times out" testing sometimes on the larger batteries. http://www.westmountainradio.com/product_info.php?products_id=cba4 It can show batteries that are starting to fade, but is easier testing smaller (6000mah and less) batteries. You can compare past and current (yuck yuck) performance, as it graphs the results over time. There is an amplifier for faster discharge (5X) but it is way too expensive. ($700) My electrical engineer son keeps telling me he will make me something...lol I've gotten so I take off, hover a bit, and check for sag. I also avoid trees and water with batteries I question. It sure is a more difficult decision with these more expensive batteries. I haven't had any problems with my Tattu or Pulse batteries. But those Zippy and Turigy have sag so bad after 20-30 flights I stopped using them, and trashed um.