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Low voltage Fantom LiPo

Low voltage Fantom LiPo

Old 12-16-2012, 02:09 PM
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Default Low voltage Fantom LiPo

Guys,

I have a Fantom / Revtech 65C saddle pack LiPo that I'm trying to recover, if possible. The battery is 12 months old, but I haven't used it at all, because I haven't run my 4WD off road car at all this year.

I pulled out all of my LiPo saddle packs during the weekend to make sure that were all around the 7.6 - 7.8 volt mark. I have two sets of Orion 90C, IP 60C, Reedy 60C and Fantom 65C batteries. All of them were fine except one of the Fantom packs (the other is fine).

When I hooked up the faulty Fantom pack to my LRP Touch charger, I got a low voltage warning. When I hooked up each cell individually to the charger, it became apparent that one cell was low / faulty. Thinking that I could revive the cell with some low amp linear charging, I hooked up my old Futaba CDR 5000 (still love that thing). It showed the dead cell was at 0.9 volts .

I hooked up the cell to the Futaba and charged it for about 2 - 3 minutes at 0.1 amps Linear to bring the voltage of the cell up to around 2.5 - 3 volts. After this, I then hooked the cell back up to the LRP charger and charged it as a single cell LiPo (3.7V) for a couple of minutes to again stabilize and bring the volts up. I then hooked up the other cell and charged as a 2S pack (using the balancer, as I always do, charging at 1C). The voltage of the pack was 6.6V. I continued to charge the pack until the volts were a bit over 7 volts. I then stopped the charge and left the pack inside my LiPo sack to rest for 24 hours.

When I hooked up the pack to charge the following morning, the pack appeared to charge normally, but the LRP cut off after 90 minutes. The pack voltage was 8 volts, but the LRP graph showed that one cell was at 4.2 volts, the "faulty" cell wouldn't budge over 3.8 volts (yes, the balancer was connected).

The cell didn't swell, deform, or change shape in any way. The pack is still sitting on a concrete floor in my LiPo sack. Can it be recovered, or is the cell dead ? And if it can be recovered, is it safe to use, or do I bin it ? I have thought about contacting Fantom, but it's kind of lame to say the you haven't used the battery at all for 12 months and it's just been sitting idle during that time. I'm positive I checked the voltage when I first received the pack and it wasn't DOA.

Any help would be appreciated.
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Old 12-17-2012, 12:01 AM
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Old 12-17-2012, 08:51 AM
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Try to fully charge both cells individually. I don't know your balancer, it may be scaled for good packs and work at lower current than your charger.
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Old 12-18-2012, 10:12 AM
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Because the two cells are so far apart your charger is SLOWLY charging the out of balance cell. Most chargers only charge around 300mah on a cell that's out of balance. The better chargers like the PowerLab 8 can charge at 1 amp/hr I believe. This is during the CV stage of charging. If you have no way of charging the one cell by itself then just keep charging it. You will see the one cell start to inch towards 4.2 albeit very slowly. What I've done in the past is take a balance extension cable (you can find on ebay), hook up the pos/neg of the problem cell to the pos/neg leads on your charger. Then charge at 1 amp. This will bring up the one cell much quicker. If after doing this the cell still won't budge over 3.8 then it's just bad and you should dispose of properly.
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Old 12-18-2012, 10:54 AM
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Hi.. take ur bad cell pack and try charging that solo.. I think that cell will never come back.. when cells go bad like that one did there TOAST.. had a Kokum saddle pack do that to me..Id contact fantom tell the u just bought the thing and see where it goes ..I have had some packs last 5 years of racing and still run like new today and had others not make it past 3 months and die.

Glade u still running the CDR5000 been trying to get one of those for years now with no luck .. I do know they can be setup to charge a lipo and get top of the line performance from them..

i would not use that cell I think ur heading to a catastrophic failure (fire poof smoke)
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Old 12-18-2012, 01:48 PM
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Thanks guys.

I have sent an email to Fantom support yesterday, just waiting on a reply.

Yes, I can charge the bad cell individually on the LRP Pulsar Touch, but as Carpet Racer said, recovering it is one thing, making sure it's safe to use after recovery is the most important thing.

Carpet Racer - I thought the CDR5000 cannot be upgraded for LiPo / LiFe use ? I do know Futaba in Japan have released the CDR6000 that is fully LiPo compatible.
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Old 12-18-2012, 02:14 PM
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Losiho.. the cdr5000 has Voltage max setting so u can use it with lipos.. I had a guy build me a board to add to my Tekin bc112c that really puts a kick in my lipos..

Glade to have helped.. have a great 1 ..
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