waisted lipos

[bill1473]

Hey guys,I let my lipos sit for a year and went to charge them the other day and my charger read that one had an open circut and the other was too low to charge.They were 4s 35c 5500ml thunder power. i have 3 sets of 3s 35c 5000ml lipos. My question is can and how could i set up these 3 packs to run my EKOS.my st up is 2 turnigy120 esc,442 props,and 10xl feagos.Any help please.dont want to spend 300+ $ on a new set of 2 4s lipos when i have 3 sets of new 3s.

[Fluid]

You can probably bring at least the second pack back to life. Hook it up to a fully charged battery for a few seconds at a time to put enough power back in for your LiPo charger to recognize. Don't be scared, this method can work as long as one pack is about dead. How did you store them - temperature, charge %, etc?

There is no "good" way to set up the 3S packs to run your 10XL motors. The 'best' way (if your ESCs will handle 3S) may be to run 3S to each motor and put on x447 L+R props. Speed will be down about 10-15% but run time will be longer. Second: you could run 6S to each motor with the x442s but that would probably blow your ESCs. Third: get new motors with a higher Kv.


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[Visual Perfection]

Sorry can't help with your problem, but $300 for a set of 4s batteries? I just bought 2 x 4400mah 40c 5s packs for like $85 new.. unless you HAVE to have thunder powers or some other really expensive brand or something...I don't see the point in those brands if you just run your boat for fun. Never had an issue with any of my Sky Lipos..and I have like 10 of them.

[TheShaughnessy]

you can also set your charger to NiHM mode and charge your lipo battery WITHOUT LEAVING THE ROOM you have to sit and watch the charger until voltage is up to 12.1 v for a 4s pack, once you get it there lipo mode should charge it like normal. It is also strange that you have an open circuit with them just sitting around. did you short circuit them?

when i read the title of this thread i thought there was a new LiPo belt or something. Waist. a part of you body that pants or shorts rest on.EX I need to let out the waist in a pair of shorts, My waist size is 33 Waste: garbage, trash etc. EX All of those pieces are waste, we cannot use them.

I know its a boat forum not a grammar forum but, its a little pet peeve of mine and i keep seeing people using the wrong form of a word.

[bill1473]

Dude, really?

[BHChieftain]

I think he means : "my lipos drank too much tequila last night and now they are waisted".

When I put my lipos into an 12 step program, they began to hold a charge much better.

Chief

[boater57]

My waist got lost some time ago...............

[battlefury]

you can also set your charger to NiHM mode and charge your lipo battery WITHOUT LEAVING THE ROOM you have to sit and watch the charger until voltage is up to 12.1 v for a 4s pack, once you get it there lipo mode should charge it like normal. It is also strange that you have an open circuit with them just sitting around. did you short circuit them?

when i read the title of this thread i thought there was a new LiPo belt or something. Waist. a part of you body that pants or shorts rest on.EX I need to let out the waist in a pair of shorts, My waist size is 33 Waste: garbage, trash etc. EX All of those pieces are waste, we cannot use them.

I know its a boat forum not a grammar forum but, its a little pet peeve of mine and i keep seeing people using the wrong form of a word.


Yes, NIMH charging mode works for unbalanced cell if voltage is below or around 2.7V. I had one of those garbage lipos for testing purposes and offen had unbalanced cell after a series of testing. Because some chargers will prompt "low voltage err" if voltages falls to 2.7V hences, i used NIMH charging mode to charge up that lazy cell. You can switch to normal lipo charging mode when voltage restores to normal hopes this helps

[Chuck E Cheese]

all of you guys are nuts. one of my friends almost burnt his house down playing with bad lipos. throw them away and get a couple 4s packs from HC

[Fluid]

Silly post. One of my friends almost burned his house down 'playing' with "good" HK LioPos. :olleyes: If the guy is careful following LiPo safety rules then he is not in any danger. If he is a fool, he'll burn his house down eventually anyway. Sheesh.



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[Chuck E Cheese]

just saying, for $100 i would throw that crap away and start over. ive never had any problems but there alot of people that have

[785boats]

Bill.
Regenerative Charging, as Fluid suggests, is an easy way to bring a low voltage pack up to above 3.0 V/cell for the charger to recognise. So is the NiMh mode on the charger, as the Shaughnessy & Battle fury explained.
All three methods are regularly performed by people who aren't nuts, Chuck E. Just got to get your colours & polarities right.

With regenerative charging, I usually put one of these meters in between the batteries so I can see what is actually happening.
http://www.hobbyhot.com/G.T.-Power-High-Precision-Watt-Meter-and-Power-Analyzer.html

Also, when I come back from the lake with a few fully charged packs I discharge them into depleted packs until the current flow reads zero. At that point both packs are at a resting voltage of around 3.8 - 3.85V per cell, depending on the state of depletion of the empty pack. Usually takes 20 minutes or so. I then have two packs at storage voltage without even starting up a charger. How's that for reducing my carbon footprint?
Note...always have the same cell count packs when doing this. Either both 4s, or both 6s etc.

Bill.
Sounds like you will have to open the pack to see where the open circuit is. Could be a failed cell or just a tap wire disconnected. Or a tab broken off one of the cells. Check for corrosion in the balance tap plug too. One pin just might not be making contact with your charger..
People at our club often give me packs with the same symptoms as yours to check & fix. There's a couple on my bench right now. If it is a cell problem I just remove it & turn a 4s pack into a 3s. Or a 6s into a 5s or 4s,(by removing a good cell too) depending on what the guy wants.
It's no biggie for me but do not try it if you are not confident. That goes for anyone that reads this.
Cheers.
Paul.

[skiking1739]

Hi to All,

This is an interesting thread as I too just received (2) 2s 45c 5000mah Flightmax. Cell No.1=3.50 and Cell No.2 =2.71. With unequal cells (one above low voltage and one below low voltage) can saving this lipo be
accomplished in the NIMH mode, and if so what are the parameters for 2s?

Thanks,
SkiKing

[sanyijr]

Just like all the threads say. Set the charger to NIMH setting at really low output amperage and push up the pack voltage to just past min. needed to register on teh balancer. Then switch over to lipo charge and balance. (I would do it slow to make sure teh balance tap has time to discharge the high V cell)

I personally had one pack get zapped by a bad ESC and the balance taps shorted, so one cell was down to under 1.0V while the other was above 3V. I put on the NIMH setting and pushed the pack voltage to 2.5V was all I needed. Then put on an Equinox balancer on the balance taps and slowly brought up the pack to full charge. i would suggest in monitoring the high V cell to make sure it does not go over 4.1-4.2 while the pack is brought back, till the low V cell is the same and pack is balanced.

Now, I have run that pack hard and the cells are always really close in voltage and discharge the same as it's paired pack (running 2 packs in series). i have 20 runs without any odd circumstances...

My 2 cents.

Sean

[maxmekker]

Just to make sure ( I have been chargin lipos for years) but never had a bad one untill now. Cell 1 is 1,45v and cell 2 is 3,85v turnigy 45c 2s pack. what is the lowest Voltage the charger would deteckt the lipo ? So I know when to stop in NIHM mode (I charger 3010)

Also what settings in nihm mode, cell count ?


Thanks a bunch.

[sanyijr]

Max,

I am not sure about that specific charger, but keep giving it a juice slowly and keep checking the high volt cell to make sure you are not in the danger zone/near 4.2V. The only time I had to deal with this, I kept checking with a volt meter each cell and then plugged in in the balancer every few minutes. BUT remember, it takes VERY little juice to increase the voltage when the cell is low. But it takes a lot to push a cell from 4.0 to 4.1. So 99% of the time adding just 1-2% of total capacity to a low cell will push the voltage up a lot, where as adding 5% to a cell that is at 4.0 may not change the voltage at all ( within 1 tenth anyways)

Does that make sense?

[skiking1739]

Say - That NIMH Mode works!!!

Many thanks for all the input on this thread. I set my charger to NIMH mode as suggested and set it on .5 amps. I only let it charge for 5 minutes at this setting, and it put in 40 mah. I then switched to LIPO mode
and cell 1 checked 3.23 (up from 2.71) - cell 2 which was at 3.5 registered 3.29. Have now been on the charger for 52 minutes and register 4.08 and 4.05, so hopefully I'm good to go.

Thanks to All,
SkiKing

[maxmekker]

I will try it later tonight, thanks.

[maxmekker]

workin a charm. Nihm mode for 40 sec @ 0,5 amp, and the cell went from 1,45 to 2,75. Charging now 1 amp, and the cell is creeping up towards the other cell wich is @ 3,95. Looking good.