Overcharged a lipo cell at 4.8V. Is it safe?

[cwah]

I was balance charging my pack while I was taking my shower with the hyperion charger.

I thought it would be safe as it has a balancing features.

But for unknown reason I have one cell that kept charging:

It seems that I have a cell at 4.8V and another one at 3.3V. How could that be possible during charge?

Can I still use the pack?

 

[Jeremy Harris]

Have you double checked the cell voltages with a meter?

Before worrying too much I'd investigate as to whether the Hyperion is misreading the cell voltages, as that seems more likely. A cell at 4.8 V will almost certainly have puffed and got a bit warm, too.

 

[cwah]

Thanks Jeremy. Just checked with my celllog and everything seems fine.

I unplugged the lipo and put it back to the hyperion and everything is fine too.

Was so afraid of burning my house lol. It was a bad reading from the hyperion finally

 

[Ykick]

Good RC Lipo lesson, trust no single meter and verify everything at least once - sometimes twice or more!

 

[Drunkskunk]

... while I was taking my shower with the hyperion charger.

And Uhh.... Deathwish?



Shocking!

 

[cwah]

lol. I'm not so satisfied by the hyperion finally.

It's not a very usable product. It's buggy sometimes and the support non existant!

 

[dnmun]

... while I was taking my shower with the hyperion charger.

And Uhh.... Deathwish?



Shocking!



you know it's personal when the relationship reaches the shared shower point.

 

[cwah]

If only it was true

 

[dogman dan]

Made me look with that title. I'm just curious how the hyperion showed such a high false voltage reading.

I've been more worried about the opposite, a bit of resistance from a flaky connector on the JST plug, and next thing you know the thing is actually charged above 4.2v, but the charger thinks it's still at 3.9v or something, and keeps on rocking charging it higher and higher till she blows.

I suppose at some point, the charger would stop because the whole pack voltage got too high. Hope so anyway.

 

[cwah]

I was really afraid that the pack would explode in my hand..

And at this very moment I thought:
"The safety of the A123 may worth something finally" :lol:

Especially because I think I have a weak cell. Look the red cell on charge:

And on discharge:

Above 4.1V and below 3.65V, my red cell peaks of cliff.. So I'm wondering how this cell is going to behave in 6 months, 1 year.. :?

 

[Ykick]

So I'm wondering how this cell is going to behave in 6 months, 1 year.. :?

Probably the same way it behaves now. You were lucky this time it was only false high reading - the real danger is when it's the other way around. My iCharger showed 4.16V on one cell but actually measured 4.25V measured with DVM and CellLog.

May I suggest that in the future you resize your pics so they don't get cut off? Me and probably others wanna follow what you're posting but it's practically impossible to view the RH side of your pics since they're cutoff in your posts. Reducing the physical image size seems to correct this board issue.

 

[cwah]

Changed all of them to 640*480. is it better now?

 

[Ykick]

Much better, thanks!

That one red cell appears to have lower capacity than the others in the series string. As long as you don't allow it to go critically low or high during the course of use it will probably remain in pretty good shape for a long time. I didn't see Ah used during the test but that cell is the capacity limit of the brick.

Kind of a shame since the others have a little Ah/Wh left to deliver but it's not a huge difference judging by the fact they're all beginning to take a dive.

 

[docnjoj]

Looks like 3.67 or slightly higher would be the stopping point for that pack. Just to be safe.
otherDoc

 

[999zip999]

I never go below 3.6v or close, no power. No point. Small packs and testing the limit's ? $$

 

[999zip999]

My 1420 charged a cell to 4.3v till I stopped it. I thought it was set to 85-90% tcs or 4.150v. Just unlpuged it.

 

[cwah]

Damn, I'm so unlucky. Would that be considered as a bad pack for hobbyking if I report that to them? (not now, but for the future one)

zip999, do you often have this problem with the hyperion? It seems that it may not be as reliable as expected.

 

[999zip999]

I have a 1420 with a 24v 1000w for a A123 20AH pack 2-12s. to be assembled. So hooked it up to my 18s 10p konion pack and a cell it floated to 4.3v at 90% tcs on one cell. So I been useing my ping 48v5a charger turned up to 74.2v and check with hyperion pack sentry @ 13usd from aircraft something in japan. They like it so why not 4.111-4.128v all 180. Maybe, I have a lot of those cells runaway or die to zero. I treat them like lipo at 4c. I was going to buy a second 1420 but thinking about using a 900w bms charger for the 24s A123. Maybe with 2 dails and a C.A. (wishing).
edit: one knob for amps and one for volts aka Doc's setup

 

[cwah]

For now I have 2 hyperions charger but I haven't found any way to charge my 20s at once. I still have to plug it to each hyperion and charge them individually.

The support from Hyperion is in-existant. So not a good purchase at all. Only 1 hyperion seems fine for balance charge when it's needed.

 

[amigafan2003]

Made me look with that title. I'm just curious how the hyperion showed such a high false voltage reading.

I've been more worried about the opposite, a bit of resistance from a flaky connector on the JST plug, and next thing you know the thing is actually charged above 4.2v, but the charger thinks it's still at 3.9v or something, and keeps on rocking charging it higher and higher till she blows.

I suppose at some point, the charger would stop because the whole pack voltage got too high. Hope so anyway.

That's why I always set a time limit on the charger. If I know a charge talkes 120 mins then the timer gets set to 130min. If the timer is reached I can check the pack before anything untoward happens.

 

[999zip999]

I found once it goes over 4.25 it ramps up fast so a real voltage cutoff would work better.