ericrw Posted September 20, 2017 Share Posted September 20, 2017 I have run down the 7.4v of my transmitter lipo battery to 6.8v. When I attempted to re-charge the Sigma charger beeped and a message came on the screen stating that the battery is full; which is not !! Advice please !! Eric. Edited By ericrw on 20/09/2017 16:20:28 Quote Link to comment Share on other sites More sharing options...
Jon H Posted September 20, 2017 Share Posted September 20, 2017 set the charger to nimh mode and charge at 100mah for about a minute. It should be just enough to kick it over the minimum voltage for the charger to then see it as the battery it is and not the battery the charger thinks it is from the voltage. Once its charging in lipo mode use the lowest current you reasonably can and watch it like a hawk while it charges. I would then treat it like a hand grenade with no pin for a little while until you are sure its not going to misbehave Edited By Jon Harper - Laser Engines on 20/09/2017 16:40:49 Quote Link to comment Share on other sites More sharing options...
ericrw Posted September 20, 2017 Author Share Posted September 20, 2017 I did not have any luck with my battery! Thanks anyway !! Quote Link to comment Share on other sites More sharing options...
ericrw Posted September 20, 2017 Author Share Posted September 20, 2017 Jon, When you state 100mah on the nimh mode, is this shown on the charger as 1.0. This is the mah, I used ! Quote Link to comment Share on other sites More sharing options...
Dave Bran Posted September 20, 2017 Share Posted September 20, 2017 Hang on a doggone minute, a 7.4V 2 cell Lipo should not trigger ANY sign of LOW voltage at 6.8v, and should NOT need the NIMH treatment as its over 3v per cell!!!!! If you are sure the warning was "full", I suggest the balance ports was not connected fully or more likely had a high resistance contact or contacts. Often removing and replacing the balance plug a few times clears that. Quote Link to comment Share on other sites More sharing options...
Dave Bran Posted September 20, 2017 Share Posted September 20, 2017 Posted by ericrw on 20/09/2017 17:22:06: Jon, When you state 100mah on the nimh mode, is this shown on the charger as 1.0. This is the mah, I used ! A milliamp is 0.001A. so 100 is 0.1A Quote Link to comment Share on other sites More sharing options...
ericrw Posted September 20, 2017 Author Share Posted September 20, 2017 The turnigy 4.0 transmitter lipo battery does not have a balancing plug. You have to charge it on Lipo 2 cell on "charging". Any further advice is appreciated !! Quote Link to comment Share on other sites More sharing options...
Denis Watkins Posted September 20, 2017 Share Posted September 20, 2017 If it is this one Eric The Turnigy DX Series Intelligent Transmitter Pack also features a built in voltage protection circuit, this circuit will automatically cutoff once the pack drops to 2.95v per cell ensuring the battery will not be damaged if you accidentally leave your transmitter switched on. The voltage protection circuit will also restrict charging to 4.2v per cell ensuring the pack can never be over charged. Quote Link to comment Share on other sites More sharing options...
Dave Bran Posted September 20, 2017 Share Posted September 20, 2017 OK, does not alter the fact that a 2 cell LIPO supposed minimum is 3v per cell so 6v, and above info says 2.95v per cell, as good as the same. A pack down to what you reported you had should not have produced any error message be it low or full. Personally I ditched using any early no-balance port fitted LIPOs years ago. I have also ditched more than one charger for not balancing well enough in terms of max voltage cut off under balance mode. Once one cell deteriorates and the charger starts pumping the other cell over voltage to compensate, you will understand why. Now some may think me paranoid, but as a fellow club member had his garage and then from the sparks his house burned down by a charger pumping a LIPO beyond critical on non-balanced charge, I rest my opinion, m'lud. Quote Link to comment Share on other sites More sharing options...
Dave Bran Posted September 20, 2017 Share Posted September 20, 2017 Note: "The voltage protection circuit will also restrict charging to 4.2v per cell ensuring the pack can never be over charged." SO, one cell in that intelligent pack has deteriorated to the point where it cannot get to 4.20 and if your total when "full" is 6.8v then that cell is at 2.6 and under voltage. Replace the pack. Quote Link to comment Share on other sites More sharing options...
ericrw Posted September 21, 2017 Author Share Posted September 21, 2017 Thanks Dave, Jon & Denis for your advice but before I throw it away; there is one other matter that has arisen. Whilst lying idle the battery voltage has risen to 7.0v. Is there still any hope?? Quote Link to comment Share on other sites More sharing options...
Mike Blandford Posted September 21, 2017 Share Posted September 21, 2017 Hmmm. "this circuit will automatically cutoff once the pack drops to 2.95v per cell ensuring the battery will not be damaged if you accidentally leave your transmitter switched on" So if you accidently run the battery low while flying, the battery protects itself, while turning the Tx off so the 'plane crashes! I won't be using this sort of battery! I'd rather the battery got damaged than I lost a complete 'plane! Mike. Quote Link to comment Share on other sites More sharing options...
Denis Watkins Posted September 21, 2017 Share Posted September 21, 2017 The most important load we put on a battery is the transmitter. This one is " past it " Eric. Make certain with a new pack. Quote Link to comment Share on other sites More sharing options...
Martin Harris - Moderator Posted September 21, 2017 Share Posted September 21, 2017 The question to ask is do you trust this battery to power your transmitter reliably at the risk of hurting someone or losing your favourite model? Quote Link to comment Share on other sites More sharing options...
Dave Bran Posted September 21, 2017 Share Posted September 21, 2017 Posted by ericrw on 21/09/2017 12:52:38: Thanks Dave, Jon & Denis for your advice but before I throw it away; there is one other matter that has arisen. Whilst lying idle the battery voltage has risen to 7.0v. Is there still any hope?? To Quote Mr Eastwood "Are you feeling Lucky, PUNK?? Well, are you??" While I have successfully revived LiPos (with balance facility) that have had all cells down under 1v for a month, the route back has been one of extreme care and only done as an experiment. LiPo that have been slowly discharged down below norm usually seem to revive better than those on fast in use powering a motor type discharge. BUT batteries I have revived are NOT being used in any sort of risk situation, but are clearly marked and being used to bench test set ups. I said "Replace the pack" last night at 22:00, and NOTHING HAS CHANGED!! Personally I would be reluctant to use ANY LiPo in a Transmitter, able to be balanced or not, but in any event certainly not one that has been shown to have been "strained". Edited By Dave Bran on 21/09/2017 13:49:08 Quote Link to comment Share on other sites More sharing options...
ericrw Posted September 21, 2017 Author Share Posted September 21, 2017 It`s scrapped !! Eric. Quote Link to comment Share on other sites More sharing options...
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