Lipo - gape that cell

[Philistine]

So unlike a lot of people on this forum, I am not a pussy about Lipo. I say if it is going to go bang, lets smash fists and get this shit on.

So I have a little lightweight travel pack rolling, 10S2P, sporting it on a little Giant hardtail.

Unfortunately one night after too many beers at the office, I decided I should try plugging the redish pinkish plug into the brownish blackish hole (who hasn't done that after a few drinks at the office?), unfortunatelIy I caused a few critical phase transitions along the way, polarity schmolarity I say.... pop bang.... blah blah blah....

When I sobered up I found a 5S pack went pop on the soldered tabs, but I had also blown the balane wires, so I resoldered those - sweet.

Weeks later, my bike broke down. Turns out it is because one of the balance wires came off the positive tab, and discharged down to 1.5v.

Ok, after typing all this I just realised I could have shortcutted the above, and just said I have a 5S pack, of which 1 cell is 1.5v.....

Anyway, bottom line. because I am not a pussy, I want to see this 5S charge itself off the mark past 1.5v. Whilst the fat man tries to do crunches I want to scream in his ear "STOP BEING SO WEAK!!!! YOU CAN GET TO 4.2v YOU WEAK BASTARD!!!!! but none of my chargers will let me do this. They all come up with weak excuse warnings. Goddam Safety warning regulation. 1010B, 3010B, Hyperion 1420i, HKQuatro. So we have established that all RC chargers are rank outside homos (don't mean to offend those who prefer the same sex here). But how does a man get a decent fireworks show going? How do I get a decent set of crunches going?

 

[fechter]

Maybe put the weakling in parallel with fully charged good cell. That will get some amps flowing.

Keep the fire extinguisher handy.

 

[Philistine]

OK, well first of all I want to say I feel blessed that my idiotic thread got graced by Fechter. Right there I am winning like Charlie Sheen. Quite seriously getting that mans brain thikning about my life was on my bucket list.... how quickly would that happen? I guess what I am asking is, I have worked all week, it is 12am here, I have drunk a few wines, and partaken in a bit of incense (ok, I have smashed some sweet hydro), I have got this all set out on the driveway, and am a bit worried if I set the cells up I might fall asleep... Mr Fechter sir, what kind of time frame might I watch the fireworks over (worried I will pass out and wake up to the flaming wreck...)

 

[Philistine]

The batteries are just sitting there like the obelesk in 2001 a space odyssey....

I might go get some Sarah Lea Ultra Choc ice cream....

I wonder how many calories are in that.....

Maybe I should follow Morphs advice, and just spray 0 calorie non-stick spray on my sarah lea ultra choc ice cream.... mmmmmmmm 0 calorie non-stick spray.......

 

[Hillhater]

Phil'.. i think the cold is getting to your brain... go put some clothes on ! :wink:

 

[Philistine]

Phil'.. i think the cold is getting to your brain... go put some clothes on ! Hillhater
100 kW


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Joined: Wed Aug 04, 2010 2:33 pm
Location: Sydney ..(Hilly part !)
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It is cold. But I am allright....

Fechter is a genius as per usulal. Just stood on the driveway (and I explain this primarily for noobs reading this thread), I took a pack, a 5S Lipo pack, with a cell discharged to 1.5v, and whiildy I couldn't charge the pack with my RC charger, I connceted it in parrallel to another pack, of course Mr Fecchter was right, there was no firewoks (dammit)..... frock im derunjk now.

GONE!!!!

 

[Philistine]

3.7v on all cells in the pack now...... no fire works (you pussys..)

 

[neptronix]

for future reference, cell phone chargers that work on phones that have 3.7v nominal chemistries work dang good for this task.

 

[dnmun]

be careful using the 5V cell phone chargers on lipo. if you burn up a lifepo4 cell with a cell phone charger pushing it up beyond the 4.2V mark it only gets hot a little, but a lipo can ignite if you keep pushing the voltage up to 5V. and it is wasteful to destroy a cell from overcharging. from my own experience. FMOE

 

[NeilP]

What is wrong with mains voltage across the thing??? that will sure make it pop..used to do the same with 500 farad capacitors...about the size of a big beer can...very impressive with 240 volt mains across them

 

[liveforphysics]

What is wrong with mains voltage across the thing??? that will sure make it pop..used to do the same with 500 farad capacitors...about the size of a big beer can...very impressive with 240 volt mains across them

Perhaps 500uF caps.




Philistine- Is your goal to get fire, or to try to make a sketchy pack you can use again and maybe burn down your home? I'm neutral towards either option, and can give you the info you need to accomplish either noble goal.

 

[fechter]

I guess I was thinking you wanted to fix the bad cell.

If you want fireworks, you should connect the bad cell to about 5s cells to charge it. Even then, no guarantee of fire, but a good chance. Most good Lipo fireballs involve overcharging. If you don't want to trash any good cells, you could try charging it with an old 12v car battery.

 

[NeilP]

What is wrong with mains voltage across the thing??? that will sure make it pop..used to do the same with 500 farad capacitors...about the size of a big beer can...very impressive with 240 volt mains across them

Perhaps 500uF caps.

No, I checked a couple I still have left, actually one third of a farad, 300,000uF...big buggers, about 3 inch diameter can, 6 inch tall

 

[neptronix]

be careful using the 5V cell phone chargers on lipo. if you burn up a lifepo4 cell with a cell phone charger pushing it up beyond the 4.2V mark it only gets hot a little, but a lipo can ignite if you keep pushing the voltage up to 5V. and it is wasteful to destroy a cell from overcharging. from my own experience. FMOE

Usually they are designed to charge one cell up to 4.1v or so.
Most charge at 0.5 - 1 amp.
You have to check the voltage output of them first, of course. Yes, 5v is inappropriate.

( sorry i was not more clear, i didn't intend to advise him to blow up his cells )

 

[NeilP]

If it is only one cell gone, and it is not too late...I would strip the pack, and check each cell.

Blow the dead one, and maybe a good one for the experience, but I would keep and use the rest...convert a flashlight or similar to a lipo cell or two

 

[Philistine]

Philistine- Is your goal to get fire, or to try to make a sketchy pack you can use again and maybe burn down your home? I'm neutral towards either option, and can give you the info you need to accomplish either noble goal.

My inital goal was to repair the dodgy pack goal, but then I got drunk and was slightly annoyed that it didn't explode. I really think it is a bad idea to muck around with Lipo when you are drunk. I am expanding my rule about drinking and guns and explosives to include Lipo....

It all appears fine at the moment but I am about to charge it on the concrete driveway, and will do it sober this time.

 

[Pure]

This thread has me wondering if anyone has stuck 110V AC directly to a dodgy cell?

 

[NeilP]

I did suggest that earlier..but over this side of the water it would be 240v