Pointy71

iTrader: (6)

I bought a new 3S Lipo and charged (with balancer) it without problem.

When I tried to use it the first time by esc immediately cut off power.

When I try to discharge my charger refuses (voltage under cutoff already). It also shows 2 cells are 4 volt and third is zero!

When trying to charge it refuses as it only detects 2 cells.

When charging it as Nimh it charges but I'm afraid of fire/explosion so after 10 minutes changed to Lipo charging but charger again detects a problem.

When I try to discharge after the 10 min Nimh charge it stops after 1 minute saying process completed.

Balancing also gives a problem.

So whatever I try I can't seen to get things corrected...

Any thoughts? I'm thinking of using the battery without lipo cut of but might damage the third cell in the process. I read many threads on lipo issues and one suggestion was to only charge the single cell with low voltage. I don't see how. My charges does not have that functionality and the pack is sealed up so no clue how to go about...

Any thoughts?

zanernator

if u can just send it in i wouldn't risk anything.

burnineyes

iTrader: (17)

If you can return the pack you should do that first. If you cannot, you should immediately stop using the pack until you are thoroughly educated about how to handle the problem.

If you have a cell showing 0V on your charger then you likely have a connection problem. It is also possible that a cell is dead, but in most cases they will show some voltage. Either way you do risk a fire by attempting to charge the pack with the wrong settings.

In my opinion, you should use a Multimeter or Digital Voltmeter to check your cells thru the balance tap. Determine if you have a bad/poor connection, or a weak/dead cell. Of course a bad connection is repairable, but you should be content with your skills to open the lipo and expose the connections. A dead cell is useless, but sometimes a weak cell can be used if you are careful. Using a weak cell in any way does involve a bit more risk than normal, so keep that in mind if you decide to try and make it work. The Nimh charge setting trick only works on the weak cell itself, this setting could possibly ruin your other good cells. You can access a single cell with a small pin connector into the balance taps, or having the pack open to expose the connections. Charge the one lipo cell as a nimh at 0.3-0.5V only until the voltage reaches just above 3V, then immediately switch back to lipo mode and continue charging. This trick is proven to work well in many applications with a weak cell, but it does carry an extra risk factor.

Pointy71

iTrader: (6)

I can not return the pack (Epay ;-)

I think it is a weak cell.

The read out now is 4.2-4.2-0.0 but just after the "Nimh trick" it was 4.2-4.2-2.8. I then tried discharging which stopped after 1 minute and the read goes back to 4.2-4.2-0.0. Now the charges only detects 2S but after the Nimh charge it correctly detected 3S.

I have a Volt meter and will try to detect the weak cell. Not sure how to "read" the balancer cable wires but I'll try to find out (web link welcome ).

If not sure I'll just give up and dispose the battery...

Duster_360

iTrader: (21)

Go get a charger that charges at the individual cell level. What you're trying, especially without the balancer attached, likely will damage another cell or possibly cause a lipo 'incident' if another cell gets overcharged.

You can make a charge lead so charge an individual cell using a mini-deans connector or an old servo type lead if you can find a male connector. This is the charger I use to see if a low voltage cell can be saved -

http://www.hobbycity.com/hobbycity/s...Charge_Capable

Neu_Racer

iTrader: (211)

If one cell is still under voltage and you discharge it that's only adding to your problem.

I would suggest doing A LOT of homework on lipo cells and maybe sticking to Nimh for a bit longer.

Pointy71

iTrader: (6)

I found this:

1-Black -VE
2-Yellow +3.7v Cell1 (and - for cell 2)
3-Blue +3.7v Cell2 (and - for cell 3)
4-Red +3.7v Cell3

Which matches my cable colors.

And I found this: http://scriptasylum.com/rc_speed/_lipo.html

With my volt meter quickly realized cell 2 was the problem. So yellow = - and blue is +.

Lipo charging as 1S through the balancer wire failed (low voltage error).

Now sitting next to the pack while charging as Nimh. So far so good. Taking it slow at 1A. Will try for 15-20 minutes and then continue with Lipo charging.

Fingers crossed.

Thanks for all the tips btw (I looked for the HexTronik charger but is out of stock... Thanks anyway )

Duster_360

iTrader: (21)

I would use a lower rate charging as NiMh, when I have to do this I use 0.5amp. That way the voltage comes up a little slower and gives you plenty of time to react if anything else starts changing.

Keep an eye out for the Hextronik - they come and go quickly when they're in stock. Even if you get this lipo to charge properly as a lipo, cell 2 is prob going to be low compared to the other cells. After several low amp charges and discharges, it should come back to what the other cells read, but if you charge it as a cell, you'll get it to the voltage of the other cells right sooner. Otherwise you'll have to watch the low cell to avoid overdischarging it when using it.

I had a new 3S with a 0.28v cell and the Hextronik charger took care of it on the 1st try.