Lipo stuck at 4.10v

[whereswally606]

So while back I left my 12s 4p lipo pack divided into two 6s4p packs I got interrupted whilst charging the subpack seperately and one was left for a few months at 4.15 volts per cell where as the other was left nearer 4.05 volts. Recently I bought a thunder 1430c and was charging the two subpacks seperately to get them to come to the same voltage per cell before putting them back in series.
One pack came nicely up to 4.18v (programmed max by me) the other which was left at 4.05 volts would charge to 4.1volts per cell when the charger dropped right back to 0.2amps. Since I was getting cold and it's dark outside in the greenhouse where I do the lipo charging I gave up for the night. Do I need to cycle the subpacks to gain the upper voltage range again? so many variables here but I guess my question is of lipo is left uncycled does it require some discharging to exercise the pack. I have a 24v kettle to do this whilst I watch my cell log 8s
Thanks for your help folks.

 

[wesnewell]

Connect it to 12s then run the storage program on it to balance it first. Then try a full charge.

 

[whereswally606]

Thanks WesNewell. I think that my problem may have been a cold weather protection system. Devries mentions it in one of his lipo basics threads here on ES. Basically higher end chargers such as Cellpro 4s will limit current when the ambient temp is less than 10 degrees C which it was since I was outside and it is December 26 in not so sunny Manchester UK. It will limit to 4.10v to preserve ruining capacity by charging cold cells. (or so I read) I am hoping my Thunderpower 1430c charger falls in to this category of fancy charger but I don't know.

I learnt lots from Youtube as well about my charger. how to calibrate it with a fluke meter/cell log, that I probably want to give it 30-36 volts input rather than 12v.

I will regroup and redouble my efforts next time.

One thing I'm a little peeved about it that every sales advert declares that this charger has a data logging facility, I used to own a Hyperion 1420i, 550w which was excellent which I fitted a Bluetooth adapter and therefore could wirelessly log data to the Hyperion bundled software as well as Logview (which is excellent software). I'm disappointed that Logview doesn't appear to cater for the TP1430c but maybe their will be a similar format using a different brands setting.

 

[dogman dan]

It does sound like cold at least added to the problem. Warm the packs, and charge them again, with balancing. A cycle may help wake up the sleeping packs as well, if they sat long enough, so a short ride can't hurt them. A discharge to 3.8v first should leave them warmer when you put them back on the charger. But then they might still chill while charging in winter unless the sun warms that greenhouse.

If you must, put a heating pad under the packs while you charge them, or something hot. Heat some bricks in an oven?

Get em so they are charging at 60F at least I'd say. You could just put the packs into an ice chest, if they start out at room temp.

 

[heavymetalthunder]

With the charger you have, you can always charge up just the low cell. Being involved the RC hobby I get a few 4, 5, and 6 cell lipos now and then with one cell low. I set my charger to bring up that low cell to match the others. Sometimes when one cell is really low the charger will not be able to balance the pack. I have saved quite a few packs that way.

 

[whereswally606]

Yeah I figure I need to make another 1s harness like I had for my hyperion. It's just a pain. I should really dissect the pack find the runt and use him for a lesser duty like powering my lights. it has an ir meter so I could rematch all the cells too

 

[dogman dan]

Somehow I missed that it was being caused by a single low cell.

1. Find out which cell, and see where it's damaged. Is it dented, punctured, or puffed?

2 If not, then rig a single cell charge harness. I just pull male jst prongs from a spare extension, and just plug the bare prongs into the correct spot on the Jst. Then I can charge just the low one at 2 amps max. Or, discharge one the same way, if just one high one is the problem.

 

[Kingfish]

^+1 Sage advice. 8)

I took a USB 5.V 2A AC adapter and modified the end to mate with a Male-terminated Rainbow Breadboard Jumper Wire for Arduino, the ends of which fit perfectly into a Balance Tap.

I took just one pair out of this assembly, using the Green & White combination. :wink:

So in the case where I have all my spares unified for storage (as 5S 60 or 70-something-P), I’ll have a couple of cells that are not as strong and eventually pull a channel down. Like now – when I’ve been gone on travel for a month or more and I’ve reduced the heat to bare minimum, the pack will display a little stress and discharge unevenly.

Bleeders don’t work fast enough for me so I hot-wire a cell-channel with the 5V 2A which is enough to trickle in at about 0.2V/day. I’m not into racing; slow and easy is fine and I check the progress morning and night. Perfect for periodic maintenance.

Anyway – the parts to construct your own single-cell charger are plenty cheap and can be had for < $15.

Empowered, KF

 

[heavymetalthunder]

If you need to build a cheap but usable connector to balance one cell you can use a set of connectors that fits your charger and solder a female RC servo extention wire to it (red to + black to -). Cost about $2. Then cut away the plastic part that covers the three pins , you then will be able to plug it in the balancing battery for the particular cell you are going to charge.

 

[whereswally606]

Ok some great advices there may do king fishes phone charger idea, pretty efficient and left on a timer over night maybe. I have done the single cell charging before with the servo type idea but actually used a cut down jst connector.

Dogman you didn't mis read, there are two 6s subpacks one has a low cell but the other subpack wouldn't charger to more than 4.10v per cell I suspect due to the cold.

I am going to be building a 4.4a zephyr bms soon so will do a whole pack check when hooking that up. but as always great advice on checking for puffed cells. They are really well protected in a PVC ducting so piercing is almost impossible.

 

[dogman dan]

Bet it's possible that the packs can move enough to chafe holes in cells eventually. It might take a year or more, but still happen some day. But not so likely if you put enough extra tape, or shrink or something around them first. Soon as somebody says such and such can't happen, my bullshit alarm goes off. If they are punctured, you can tell by smell. Chances are, you just have a cell that got out of balance, and no problem. If it unbalances again every ride, that's when you gotta dig that battery out of the box and get rid of that cell.

I got one large grain of sand in a battery box once, and it dinged holes in the bottom of several packs. They were zippies, that had the bare naked pack on the bottom. I learned to tape those zippies naked butts up immediately upon arrival. And the boxes are padded on the bottom now.

I'm not writing this to criticize you, or say you did anything wrong. Sounds like you have a great enclosure, and if the packs cannot move inside there at all, chances of damage go down a lot.

It's for the thousand other readers to learn from that I keep harping on this stuff. Damaged lico packs are very dangerous. Job one when they arrive is to sort and remove the factory defects, but right after that is to do something extra to be sure they get no physical damage. It's just so easy to ding a cell, and create a real hazard.

 

[whereswally606]

Hey dogman, not offended, it is a good enclosure but they at flightmax 40c 5ah 3s cells. There is 16 of them. And I think out of that 2 had a couple of poor cells. In hindsight I should have sent the rungs straight back to hobbyking but the time past and I just wanted to ride the bike. One idea is to excise the two runts and drop from 12s4p to 14s3p and have a spare 2s/3s pack for the lights. IR meter is gonna be invaluable.

 

[dogman dan]

Good idea, to run only your best cells for now. Any cheap RC lico cell with a problem, I consider to be a fire about to happen. Once you sort down to solid performing cells, I worry very little about a fire.

Should be pretty cheap to get 6 more cells to put it back as it was later.

 

[icecube57]

[youtube]IQqC080PJUM[/youtube]

 

[999zip999]

I would be scared of a problem cell as Dogman says and can be trouble in the future.

 

[Kingfish]

I think there must be a market for something like this: Cell Repairman to the rescue! 8)

• Go to CellRepairman.com (I have no idea if this exists, so go for it)
• File for your Safety Mailer and make your deposit via pp or whatever.
• CRM sends out your safety mailer and you place your suffering battery (or- ies), seal up the box and send it back to CRM.
• CRM fixes bloated cells, dead cells, low voltage cells, damaged balance wires, upgrades your main taps, whatever you sign off on…
• CRM then sends back your goods all fixed up, or – you can elect to donate your damaged goods to some charitable mercenaries that can always use more bomb-making material. Whatever.

Just an idea…
Full of it, ideas.
KF

 

[DAND214]

KF, your too late.
It's a cell phone repair man at that URL.

You have all the fun ideas!

Dan

 

[whereswally606]

Wow some nice contributions here guys. Thanks icecube for the video I have done similar using a very cheap lipo 6s charger as a 1s. It still wouldn't go as high as the others. KF not a terrible business idea but I think posting dodgy lipo is pretty irresponsible. So no

 

[Kingfish]

Wow some nice contributions here guys. Thanks icecube for the video I have done similar using a very cheap lipo 6s charger as a 1s. It still wouldn't go as high as the others. KF not a terrible business idea but I think posting dodgy lipo is pretty irresponsible. So no

I have low friends in high places… no, sctatch that – they’re in low places too. And the FedEx’rs and UPS’rs tell me shipping dodgy LiPo is the least of their worries. When you think about it, what happens when you recycle batteries?

A pal of mine gives his to his apartment manager. He takes the batteries – any chemistry – and throws them into a bin where they sit until the bin is full. Then he tells a toady to go send it off: Toady takes the bin, pours the contents (with an uncontrolled rate of impact) into a plastic bag inside a 5-gallon paint bucket until it’s full. Seals the bag with a zip-tie. Seals the bucket. Takes the bucket and puts it into a squarish cardboard box, tapes it up, places the shipment sticker on it – then calls FedEx or UPS for a pickup. The shipper arrives, takes the box, and gives them another empty one in replacement. It could be 6 or 8 months from the time of deposit to the time they’re shipped off.

Another pal of mine works for a Telecom. Their process is much faster, but no different. The really bad LiPos I had I gave to him.

I frequently drink beer with the Shippers who ship everything from dodgy LiPo, to ammo, to gunpowder, to fertilizer, to oxygen. The list was eye-opening and sobering! Conclusion: There are far worse things they ship than bloated LiPo. Trust me. :|

The idea of a Repair Service is a good one and I’ve seen it in action (although not explicitly with batteries per se). The salient question is whether the cost of (repair + shipping + margin) is worth up to 50% of the cost of the original product. Considering your puffy is worthless without a repair, how much would you spend to refurbish it? I’m guessing up to half-price for one or two cells.

If it turns out the service cost from the Repair center is more than it’s worth then you can elect to donate or recycle and possibly recover the cost of shipping.

Given that we are all using similar configurations 4S, 5S, 6S, 8S… might be faster to cut the PCB away and solder in a new unit. Might have to give up on like-C rated cells… I’m just brainstorming.

However returning to the problem of shipping scary packages, if they’re packaged and handled correctly – there won’t be a problem. Think about it: When is the last time you heard of a fire on a shipment truck? And how many ships, planes, trains, trucks are moving product across this planet?

Waiting for the calliope to arrive, KF