Revive a lipo

[bromvw 744]

Guys is there a way to revive a over discharged lipo ? My eldest step son has fully discharged one on his 2 stroke 1/5th buggy not knowing that he should have had a cut off or alarm fitted .

I know its a long shot but just trying to help him out and save him some money . I have a imax B6 charger - is it worth giving it a go set to using another setting other than lipo or is it likely to just go up in smoke - or worse ?

[lentner3 328]

That sounds like a very bad idea. You can try and creep a voltage in to it but I would strongly advise you to ditch the pack. What voltage is it showing at the moment?

[danb1974 142]

The usual procedure is to first go to 3v/cell using nimh mode and low current (you have to stay there all the time and end charge manually), then switch to lipo mode and do a balancing charge

[lentner3 328]

Danb1974 is right and if your going to do it this would be the way however your taking a risk if your cells are well below this. Even if it works OK that pack could still be volatile. If it was my own pack I would be tempted but I would never do it for someone else, especially if it was a small cheap pack which I imagine it is.

[bromvw 744]

ok thanks guys . Its a cheapo 3000 2 s and its only powering the RX . For now I have lent him one of my packs . I'll ask him if he wants me to chance charging his but i'll advise him to just replace it . Even a NI-MH will do the job and would be less hassle for him to charge as he don't have a lipo charger of his own - hence why his has discharged . He was told that the petrol motor charged the battery by the cowboy he bought it from lol.

Its taken me the best part of the day to sort out all the bodges and get it running . Basically it was a sack of excrement - so take it to Dad to fix The usual story .

[lentner3 328]

Now that would be cool, a mini alternator.

[bromvw 744]

If only Lentner . Basically he knew very little about what looks like a HPI Baja copy . Fairly nice 1/5th scale two stroke 22cc powered buggy . Took some getting going but runs well now after changing the coil pack , spark plug and repairing the pull start and then replacing all the Bodge bolts ect . He only gave £100 for it so its not that bad a deal .

I'll help him fix it up properly and we'll find a new body for it . If it needs a new battery then so be it - for now its working fine on one of my spare NI-MI packs . it also needs a new exhaust but that's easy to find - might just fit a HPI one .

These petrol RC's aren't my thing but I must admit I enjoyed working on it . Very satisfying when you can help out family . All the bits came from my spares box's so it cost him nothing in parts either

[lentner3 328]

£100 sounds like a steal even if it did need work.

I'd love something 1/5 but just don't have the funds or space to tinker with it which is half the fun. Plus Tamiya don't make anything that big 😉. You should post some pictures up for us to see.

[bromvw 744]

Its back at his place now but next time he's here with it or we go over i'll snap a few images . knowing him it will more than likely need repairs by then though

[matman 1500]

I do this most of the time way back in 2006 with my li-po's & used nimh to top it up .

All i did was top it enough to get it over the cut off & the put in onto li-po charge after .

I have NEVER had a li-po blow up or anything like it & they went on for a long time .

You will be fine doing this , they are not as bad as people make it , all drama .

A few of us have try to blow one up & done all sorts to it & it never did a dam thing .

Sadly ..

[bromvw 744]

Come to the conclusion that its worth a try , I'll charge it in my fire proof metal box and out doors just to be on the safe side though .

[hammerstien 187]

have had to do the nihm trick a few times on lipo's 5amp charge for 5sec check if it will charge on lipo if not do again always worked never had one do anything strange but just in case charge out side in middle of patio

[lentner3 328]

If your going to do it just be safe. Out of interest those that have had sucess how low had you packs voltage got?

[SteveU30 1011]

I've done it a few times, once on a pack that was fairly well discharged (left the LiPo alarm plugged in for a week before I realised that continues to discharge the battery too over time).

I charge at 1A until it gets to 6v (3v per cell) then switch over to a proper balance charge and stand over it for the duration of the charge and watch it like a hawk.

[ddaenen1 278]

I also revived a lipo more than once. Charged in NiMh mode on very low current (0,3A)and monitoring the voltage constantly until i was on about 3,5v per cell. Then switched to Lipo balance mode and charged it fully. After that, a couple of discharge/charge cycles in lipo balance mode and all well.

To date, always has worked.

[hammerstien 187]

lowest mine ever got was about 0.9 volt per cell . but came back to life

[lentner3 328]

wow thats very low. interesting

[hammerstien 187]

always find couple of nippers at club forget to unplug lipo after last race and forget about it till next race

as long as it is above 0.5v per cell they can be brought back but lower and they are dead