rickyrocket

I've had three TP 3s/2100's die on me so far. ONly one was in a crash. The other two have one cell that swells and gets soft so I have retired them. I would guess these cells only had 20 to 30 flights on them each. Cutoff occurs at 11.1 so they certainly have not been over discharged. Is this normal? How long can a lipo be expected to perform safely?

Also, Can I use a new lipo in parallel with others that have been used or do I need to buy two at a time?

Thanks

exeter_acres

My Feedback: (2)

how are you charging them? what are you using them in?

Sounds like the are not holding up well.....and getting over taxed

there are many variables with Lipos but if you are good to them...300 or more cycles is not uncommon

Greg Covey

Unfortunilty, the current packs on the market do not have taps to measure the voltage at each cell. what happens is that one cell is weaker than the others and slowly gets undercharged over time as the other cell (or cells) get overcharged. It is actually the good cell (or best cell) that ends up going fubar.

This will end soon with the introduction of the SKYVOLTS system from FMA Direct. Each cell is monitored on both charge and discharge so that the weakest cell determines when to cut off the motor and all cells get properly charged on every cycle. Documented tests show no loss of capacity after 200 cycles at the rated continuous discharge and (this is the best part) a 3C rate recharge of only 20 minutes for 90% capacity.

Check out the R/C car magazines for SCORPION 2-cell packs. They are the predecessor for the airplane SKYVOLTS packs.

draganfly.com

My Feedback: (40)

Greg, you seem to be forgetting that Tanic has offered taps for about a year now, Polyquest for about six months, Apogee for a few months, and Thunder Power is transitioning (currently only the 2000mah packs, 1320 packs in a few weeks, the rest in the next four-six months).

draganfly.com

My Feedback: (40)

In case anyone is wondering why Greg "forgot" to mention all the other brands that beat Kokam:



PRESS RELEASE MAY 7, 2005

GREG COVEY JOINS FMA, INC AS DIRECTOR OF SALES AND PROMOTION, EFFECTIVE JUNE 1, 2005

FMA, Inc is pleased to announce that Greg Covey has joined the firm as Director of Sales and Promotion. Greg has enjoyed a distinguished career in development and marketing of high technology radio links and wireless network communications over the past 27 years. He brings to FMA not only consulting skills in radios, software, and networking but also his skills in developing and marketing sophisticated radio systems. Greg is very well known in the RC modeling community for his work with Quiet Flyer, RC Universe, and RC Groups over the past six years. We at FMA are most impressed with Greg’s ability to assemble, evaluate, and contribute concise, clear written reviews and articles for a wide range of products in a short time. His general knowledge of the RC market and interpersonal skills with modelers makes him a well-known figure in RC. His formal education in electrical and information technology equip him well for the tasks at hand. We welcome Greg into our business organization and sincerely feel that the entire RC community will benefit from the acquisition.

AgCat1982

Congrats Greg!!!!!! Way to go!!!!! Best of luck to you!!!!![sm=thumbup.gif][sm=thumbup.gif][sm=thumbup.gif][sm=thumbup.gif] Oh that I could have such an opportunity come my way!