Rescue or chuck?

[Planehazza]

Left backup pack plugged in for months (again!) and now it's not registering on my Lipo checker. Multimeter reports 3.4v and 3.3v on the 2S pack. Rescuable or disposal time?

[crash-test-tomo]

For the sake of the 10quid the opti 2s costs id bin it

[milly0812]

For the sake of the 10quid the opti 2s costs id bin it

The guy is from Newcastle #tightasarseholes

[Grumpy]

if it's got 3.3 and 3.4V left in it then it should be ok. Just plug it in the charger and see if it charges up ok, no reason why it wouldn't.

[Planehazza]

Not being tight. But why spend money when I don't have to? Not made of the stuff

[_tj_]

Try it on a charge not balance or fast charge.
Don't plug the balance lead in.

If that don't work.
I've rescued a couple on a nihm charge at 0.5a.
Until the cells are bumped up enough for the charger to read it.
Then just balance charge it.

I wasn't buying a new 4s 10000mah if I didn't have to lol.

[cycled]

Not sure I agree with TJ: I think most chargers should handle 3.3V fine (down to maybe 3V). Give it a cycle on the charger (1C and balanced) and check capacity; probably it's fine if it doesn't puff, have high IR or become unbalanced.

[Grumpy]

Yeah, 3.3V should charge perfectly ok, no special precautions or workarounds required. It's only once you go below 3V that the charger might throw up an error for low voltage.

[_tj_]

I think mine were below that.
But it is likely not going to charge as a lipo at 3.3v
As this is the nominal voltage for liFe batteries.

My charger turnigy reaktor an most others have a setting to charge LiFe batteries an sets the charger to 3.3v

Just had a check in my charger booklet.
Standard battery parameters
Lipo
Nominal voltage 3.7v/cell
LiFe
Nominal voltage 3.3v/cell

If you have a fussy charger it won't charge a lipo under 3.6v
This charger supposedly detects an over discharged battery an
trickle charges at 0.1A until the cells are back to charging voltage.

Typical though.
I haven't done it since I got these changes lol

[james_2k]

wont charge below 3.6?? that's not even slightly true. Not going to charge as a lipo? you need a new charger man

Nominal doesn't mean minimum

wouldn't even be slightly concerned about 3.2 on an optiguard pack. (mine was at like 0v when i noticed it, bad times )

[Grumpy]

As already mentioned, 3.7V is the 'nominal' or 'average' voltage. Most chargers will happily charge a lipo that's 3.0V without any issue at all. I think Powerlabs will go down to 2.8V. I've personally charged LiPo batteries from below 3.3V more times than i can count.

In the ideal world of course you shouldn't run them that low, but once in a while doesnt do any immediate harm.

[cjm180]

Hey

I have an opti power 2s rx pack that was brand new. I picked it up by mistake when I was setting up my goblin. I plugged it in to power the electronics, then half way through everything stopped working.

It took me a few mins to work out what was happening, but the axon and futaba rx shut down on low voltage.

I cant remember what the voltage was, but as it was a futaba rx I guess it was less than 3.3V. I remember plugging it into my 406 duo charger and a few mins into the charge it came up voltage error. I kept trying it and eventually the voltage came back up and it completed the charge.

It has been fine ever since.

Kr
Craig