View Full Version : Is this battery shot?

Visual Perfection
07-01-2010, 01:27 PM
Hey guys,

Just bought 3 Lipos (2s 30c 5000mah) and upon arival I tested all 3 of them.

One had 7.35 volts

One had 7.65 volts

However the 3rd one has 3.49 volts : (

I am assuming this means either:

a.) one cell is bad

b.) each cell only has 1.25 volts in it which means the pack is shot?

Any insight on this would be great, maybe I am wrong?

Thanks guys!

07-01-2010, 01:46 PM
How did you test them? My charger will show individual cell voltage, which may help in your case. But, if that is the voltage for the total pack, doesn't sound good.

Visual Perfection
07-01-2010, 01:55 PM
I used a digital multimeter to test them, same way I have test all my batteries.

I don't have a lipo charger yet. (bought lipos first, getting charger for my B-day on the 11th) so I can't check it with the charger until I have it.

If I can't balance charge it back to life the seller will make things right so I am not worried about that at all, just a little bummed I will have one less Lipo.

I assume best way to do this is once I get the charger, check to see what each cell has in it, and if it shows one cell dead then it is shot? Or If it shows both cells really low, I can attempt to balance charge it and see if it comes back to life?

Thanks for any help!

07-01-2010, 02:05 PM
If your multimeter has sharp enough tips on the prongs, you may be able to test straight from the balance tab contacts.

Visual Perfection
07-01-2010, 02:11 PM
hmm.. good point. I think I will try that. There is a red, blue, and black wire on the balance tab...which is the positive for each cell, which is negative.

I just don't want to short anything!

07-01-2010, 02:14 PM
I would imagine black is negative, and the other two are the positives for each cell. Better wait for a lipo expert though. Wouldn't want you doing any damage because of me. haha

07-01-2010, 02:40 PM
use your meter put black probe on black wire and red on the next wire over see voltage.

then put the black prob on the second wire after the first black wire and then put the red prob from meter on last wire and see voltage.
this should show each cells voltage

07-01-2010, 03:56 PM
you will not short anything, a digital multi-meter can read negative voltage. just be careful not to make contact across the probes and make a short through them. even if the pack is low you may still be able to bring it back if the cells do not fall too far out of balance.

Visual Perfection
07-01-2010, 05:25 PM
Ok just tested the cells.

First cell has 3.24 volts in it

Second cell has .25 volts in it

Which makes sense why I am getting 3.49 volts when I test the positive and negative leads lol.

With that said, is it even possible to bring it back to normal...or is it going to be a no go for this pack?

07-01-2010, 05:26 PM
I'd be hesitant to try and save that, especially if the seller is willing to make things right.

07-01-2010, 06:34 PM
looks like a gonner.:ThumbsDown01:

Visual Perfection
07-01-2010, 07:06 PM
I'd be hesitant to try and save that, especially if the seller is willing to make things right.

How would you even go about saving it if you did? Just plug it in and balance charge it very slowly and the charger/balancer would attempt to even them out?

Just would like to know as Yes the seller will make it right, but he has asked to see if it is possible to bring it back to life first, and I would like to at least try.

Will it be dangerous to do this?

I know it is probably gone, but at least giving it a try would absolutely confirm that.

Thanks again guys!

07-01-2010, 07:11 PM
I'd search the forum for people who have resurrected excessively drained cells. I don't know the best path to bringing them back. Was just advising that the voltage that cell is at is considered dead from what i've read.

07-01-2010, 07:34 PM
Just so you know the whole story...I am the one who sold him two brand new never used xps 2s 5000mah 30c/50c lipos...I paid $60 each for these and I sold them to him for $70 for both batts...he asked if I had one more lipo I said yes but it was used and he offered me $20 and I said ok and shipped all three for $90

he told me he had issues with the used one not being balanced so I asked if he would try to ballance charge it before I return his $20 and if it didnt work I would make things right..(give him $20 refund)

here is the exact product

and here is a thread on the review of XPS lipo's.......they are not junk batts


Nick if you dont want to try to balance charge it..... just say so and I will return your $20 NOW

Visual Perfection
07-01-2010, 08:04 PM
No worries buddy, I was just trying to see if I could indeed bring it back to help you out so you wouldn't have to refund me. Looks like it isn't going to happen though.

Just so everyone is clear now that you posted....Bustitup is a great seller and I would not be hesitant to purchase from him again!

07-01-2010, 08:35 PM
I don't think anyone was questioning bustit. Just trying to advise you on the pack.

Visual Perfection
07-01-2010, 08:56 PM
Oh I know nobody was questioning that, I was just making it clear that I am not unhappy and he was a great seller

07-02-2010, 07:45 AM
Sounds like the pack has bit the dust. If it had at least 6 volts total you could start charging it as a 2 cell and see if the voltage of the lazy cell starts to come up. Time to pitch it.

XPS packs have gotten very good reviews. Kinda surprising.

07-02-2010, 08:59 AM
Sounds like the pack has bit the dust. If it had at least 6 volts total you could start charging it as a 2 cell and see if the voltage of the lazy cell starts to come up. Time to pitch it.

XPS packs have gotten very good reviews. Kinda surprising.

we will see....I am buying the pack back from him and will attempt to balance charge it very slowly

07-02-2010, 10:20 AM
Keep us posted bustit!

07-02-2010, 10:23 AM
That far out I doubt you can bring it back. No charger that I know of will attempt to bring back a lipo from that far.

The best luck I have had with bringing back lipos is to charge them as a nimh or nicd at a low amp rate and watch the pack and the voltage very closely. No charger that I know of will balance a nimh, but the goal of charging it that way is to bring the voltage up to a level where you can start charging it as a lipo.

That pack I would take up to five or six volts and then check the individual cells, you don't want the good one going far over 4.2 and if the bad one is not coming up then it's toast. If the dead one is recovering voltage and the good one is not over 4.2 and the pack is not getting warm or puffing, then take it up to 7 volts if your lipo charger does not like where it's at. even then you still have to monitor it closely to make sure the cells are not getting warm or puffing or getting too far out of balance.

Also, if you are going to attempt this, have a plan. If or when the lipo gets hot or starts to puff or the charger throws a bad error, have a plan on where to put the battery. have a glass or ceramic container or lipo bag available and a well ventilated area clear of flammable items where you can put it for observation for a while.

07-02-2010, 10:43 AM
I wouldn't even attempt it without out my lipo bag........thanks for the input

07-02-2010, 06:26 PM
You can charge it at a low rate through the balance tap. You can charge just that one bad cell this way.