dave barrett Posted January 7, 2014 Share Posted January 7, 2014 Hi have been charging my 2200 mah 3 cell battaries. But the charger does not cut of when its reached 12.6 volts. It set to cut of when it reaches 2200 mah. It still keeps charging when each cell has reached 4.2. Am I doing sonething wrong.Dave Quote Link to comment Share on other sites More sharing options...
Paul Marsh Posted January 7, 2014 Share Posted January 7, 2014 Nasty! Be careful you don't blow the lipos and fire. Really chargers should n flat,and even then it's knackered ever go by capacity, as 2200mah battery is never attainable,unless it's totally Quote Link to comment Share on other sites More sharing options...
Frank Skilbeck Posted January 7, 2014 Share Posted January 7, 2014 Not necessarily, when the charger gets to 4.2v per cell it should start to reduce the current and the charging then finishes when the battery won't accept anymore charge at 4.2v per cell. So say you start with a discharged battery at 2.2 amps, initially the charger will put in 2.2 amps and as the battery is charged up the voltage will increase until it reaches 4.2v per cell, then the charger will reduce the current to maintain the charging voltage at 4.2v, once the current has decreased to <0.1A it should cut off. If the voltage goes above 4.2v per cell then there is either a fault with the charger or it's not set for a 3s lipo. Quote Link to comment Share on other sites More sharing options...
dave barrett Posted January 7, 2014 Author Share Posted January 7, 2014 Charger it set for a 3 cell lipo and it charge above 4.2 volts so had to switch it off. Should I discharge to correct voltage Quote Link to comment Share on other sites More sharing options...
Frank Skilbeck Posted January 7, 2014 Share Posted January 7, 2014 Yes, I would partially discharge the Lipo and then get the charger checked over if it is allowing the cell voltage to go above 4.2v per cell. Quote Link to comment Share on other sites More sharing options...
dave barrett Posted January 7, 2014 Author Share Posted January 7, 2014 Just went to discharge battary and it was shown that each cell was below 4.2 volts as before was above when charging. Quote Link to comment Share on other sites More sharing options...
Phil Green Posted January 7, 2014 Share Posted January 7, 2014 Lipos have a two-stage charge cycle. Constant current until they reach 4.2v per cell, at which point the charger switches to constant voltage util the software deems that its full. During the constant voltage phase the current might remain for a while at the initial charge current, but will quickly start to reduce to almost zero. The CV phase can be frustratingly long but can be cut short without any long-term effects if you dont need to achieve absolute maximum capacity. Cheers Phil Quote Link to comment Share on other sites More sharing options...
dave barrett Posted January 7, 2014 Author Share Posted January 7, 2014 So even if it saying 4.2 volts per cell the battary has not reached full capacity. Is that what your saying so as it charging the voltage increase and then levels out to 4.2 it reached full is that correct. Sorry for all tge question new to electric flight so trying to get my head round it cheers dave Quote Link to comment Share on other sites More sharing options...
Phil Green Posted January 7, 2014 Share Posted January 7, 2014 No, not exactly. A full capacity charge is achieved only after the CC charge to 4.2v then the CV period to 'top up' the charge. BUT if your charger allows any cell to exceed 4.2v at any point then its faulty (and dangerous) Cheers Phil Edited By Phil Green on 07/01/2014 19:22:30 Quote Link to comment Share on other sites More sharing options...
Simon Chaddock Posted January 7, 2014 Share Posted January 7, 2014 Perhaps the important question is what current is it showing when it is at 4,2V per cell? If the charge current is right down to 0.1A then as Frank says it could take along time, particularly if the cells were a bit out of balance as it only cuts out when all the cells hold 4.2V for some period with no current flowing. My B6 charger frequently goes to its 120 minute limit without cutting off but once reset it does cut off eventually. . Edited By Simon Chaddock on 07/01/2014 19:28:01 Quote Link to comment Share on other sites More sharing options...
dave barrett Posted January 7, 2014 Author Share Posted January 7, 2014 Its new dynamic 3cell 2200 battaries. It was charging over 4. 2 volts it was up at 4.4 volts Quote Link to comment Share on other sites More sharing options...
Phil Green Posted January 7, 2014 Share Posted January 7, 2014 Your charger is either very dangerous, or badly calibrated Dave. Either way, it needs sorting or replacing. Quote Link to comment Share on other sites More sharing options...
dave barrett Posted January 7, 2014 Author Share Posted January 7, 2014 Will contact airteck hobbies then.and let them know. Quote Link to comment Share on other sites More sharing options...
Phil Green Posted January 7, 2014 Share Posted January 7, 2014 Just had a thought Dave, you are using the 'balance charge' program on the charger? The straight 'charge' program will happily allow one cell above 4.2 if another happens to be low to compensate, ie it is only looking at the overall pack voltage. Quote Link to comment Share on other sites More sharing options...
dave barrett Posted January 7, 2014 Author Share Posted January 7, 2014 Was using just using the charge program all the cells were above 4.2 Quote Link to comment Share on other sites More sharing options...
Olly P Posted January 10, 2014 Share Posted January 10, 2014 Speak to the supplier in this case, if it is letting more than one cell go above 4.2V there looks to be a fault. I would also check the program settings, and ensure set to 3S. Quote Link to comment Share on other sites More sharing options...
dave barrett Posted January 10, 2014 Author Share Posted January 10, 2014 Hi olly. I checked the.setting was set.correctly 3 cell.2200 lipo end voltage 12.6 but.still went over. Spoke to supplier going to send. An ither out so hopefully have it soon. Cheers dave Quote Link to comment Share on other sites More sharing options...
Paul Marsh Posted January 10, 2014 Share Posted January 10, 2014 If I would you, I would dump the charger, get another one before it all ends in tears. Not only could you destroy the battery, but set fire to yourself and property. Someone here burnt their hand when the lipo went up. Do the sensible thing, buy a new charger NOW! Quote Link to comment Share on other sites More sharing options...
Olly P Posted January 10, 2014 Share Posted January 10, 2014 Paul - From the post above your last one it appears the supplier is shipping a free replacement. I would mark up the old one very clearly to avoid getting them confused! Quote Link to comment Share on other sites More sharing options...
dave barrett Posted January 10, 2014 Author Share Posted January 10, 2014 Hi paul.. It was a brand new charger charging new lipo battaries.. Charger has been sent back for a replacment Quote Link to comment Share on other sites More sharing options...
dave barrett Posted January 10, 2014 Author Share Posted January 10, 2014 Hi paul.. It was a brand new charger charging new lipo battaries.. Charger has been sent back for a replacment Quote Link to comment Share on other sites More sharing options...
Paul Marsh Posted January 10, 2014 Share Posted January 10, 2014 That's ok, probably a software fault. Quote Link to comment Share on other sites More sharing options...
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