kg4izw

I use Thunder power Pro Lite 1320mah batteries to fly my DF electric helicopter and one of them has recently started acting strange.
It only gets 5 to 8 minutes per flight instead of 10 to 12 that I get with my other batteries just like it. And when I land after using it, the battery is MUCH hotter than they normally get. I think I have a undercharged or over charged cell in there somewhere. The battery manufacturer will not help me since the battery is over 90 days from date of manufacture. This battery also has some sort of circuit board inside the pack. Is it possible to cut open the pack, isolate the defective cell, then replace it to restore the original performance of the battery? If so, how do I find another cell pack with all the identical specs of the original? Would it even be safe to make this repair myself? I'm at a loss here, but dont want to toss a battery with less than 30 cycles on it that would cost $70 to replace.
Thanks, paulb.

TampaRCGuy

My Feedback: (282)

Have you balanced the pack?

exeter_acres

My Feedback: (2)

sounds like it is going bad...

as above... do you balance it..

do you over discharge the pack?
what charger do you use?
What is the voltage of the pack when you are done flying?


and if you are paying $70 for a 1320 pack, you are getting ripped off... they should only be about $52 - $54

kg4izw

There are no balancing wires on this battery. The charger I have is built to charge this battery. It was bought from RCToys.com. The battery reads 10.3 when it is low, but only 12.0 when charged. The other batteries read 10.3 when low but 12.67 when full. The reason the price of this battery is so high is because of its high discharge rate. It is 15 to 17C. Is there a way to balance the battery without the balancing wires?

will

Unless I'm missing something, the Pro Lite TP batteries come wired with a balancing lead.

The only way to balance a pack that doesn't have a balance lead is to install the wiring yourself. That process can cause bad results if your not very careful.

loudbikes

My Feedback: (38)

He mentioned that it had an internal circuit board. On RCTOYS.COM I read something about an internal circuit board for self-balancing and over-charge/discharge protection. The "DF" as he called it is the Dragonflyer 4 bladed helicoper if I'm not mistaken. I wonder if it's the charger or that protection/balancing circuit board. I think the manufacturer should help you out with this one. You should get more than 30 cycles out of that battery. Maybe part of the circuitry has failed? I would talk to them again. Let us know what you find out. I have bought most of my TP batteries from them and would hope to see some good service. If I payed extra for a pack with a built in protection circuit, I would expect it to work. That's what you paid extra for. Good luck - Tim

kg4izw

I contacted the manufacturer once more and they told me to mail them my battery and they would see what they could do. They told me they would contact me once they determined the problem. Ten days passed and they never called, so I called them and we had an interesting conversation. I spoke with Tim who was extremely polite. He said that the #3 cell on my pack was below normal voltage and he could not get the pack to charge to normal voltage. He told me it could be from overcharge, overdischarge, overheating, impact shock, or a variety of other causes. He told me it would have been dangerous to try to cut and replace the cells myself. He told me the board looked OK and was not sure why it had the problem. Nevertheless he sold me a replacement battery for 1/2 price and I bought an additional one at a 15% discount. I'm not sure if this was satisfactory warranty work or not. I guess I am thinking of it like a pro-rated warranty. In that case I did not do too bad. OH, he also charged me $5.00 to ship it home to me.
Timeframe: I mailed away the original pack on October 29. I called and spoke with Tim on Wednesday, November 8. I have not received my batteries as of today.
I hope this provides you with some service incite.
Paulb.

PS- I will continue to pay the exrta to get batteries with the computer board in them.

Fred Marks

Paul, you do not have to pay extra for every pack to have the discharge protection you need. The FMA CellPro DPM
http://www.fmadirect.com/detail.htm?...117&section=45 plugs in-line between the pack and the ESC, thus protects ANY pack that you want to use. You can see how it works from the manual at :
http://www.fmadirect.com/support_docs/item_1210.pdf


Good luck,
Fred