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Puffed lipo by shorting?
Hi guys,
I got a Neu 3s 5000mah lipo the other day. I was soldering deans to it and accidently touched the two wires for a split second. it made 3 sparks. Basically i am asking if i have ruined my new lipo. i think it has puffed a bit but it could be my imagination. many thanks |
very well could have damaged it. I don't have any first hand experience but from what I've seen on here a quick touch generally doesn't damage them.
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If only for a split second you should be fine - Remember the spark you get when you first plug in a battery to an ESC - This is like a short as the Caps soak up the voltage very quickly.
I'd be suprised if you've puffed it - Check your voltage on all cells. Post up a picture... But be careful! Not worth buring the house down... Dupe post - http://www.rc-monster.com/forum/showthread.php?t=14988 |
again sorry for the dupe post. you can delete the other one or wotever lol. i'll try and get a pic of it. i actually bought 2 of the same lipos, so this is why i think it is puffed because it feels squishy on top and the other one is solid.
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What charger / balancer setup do you have - does it have built in volt meter? Do you use a lipo sack?
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these are brand new batteries. never been charged or used. im new to electric so im not really sure what is considered a puffed lipo. ive taken some pics so i'll try and upload them
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any thoughts? i know the pics arnt very clear. should i send it back to Neu? they sed i could, but im not sure if it is considered puffed. it just feels squidgy and the other one feels solid.
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Send it back Rev:-o, I gather from your posts on Traxxas you dont have a esc, motor or truck yet, so you have some time. If Neu said they'ed take it back, send it back and consider it lesson learned
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i think i'll take your advice jayjay. the only thing is ive soldered deans to it. but if they ask i can just say the shop i bought it from did it for me. www.flydma.com do it anyways
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It doesn't look puffed to me. I'd run it!
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What charger / balancer setup do you have - does it have built in volt meter? Do you use a lipo sack?
What are the voltages on each cell? |
it should be fine , i have done the same thing
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i've done the same as well when i soldered deans to my 2s 5000mah tp lipos....only a split second of sparks....i ran it til LVC, charged it back up and nothing was wrong with it :yes: you should be fine...:rofl:
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I don't think it looks puffed at all. It could still be dead, though. I sparked a MA 4s 5000 pack a while ago and 1 cell out of the 4 went dead instantly. The other 3 are still working fine. If you haven't already, get a voltmeter and check the level of the individual cells. I believe, as a general rule, if any 1 cell is more than 0.05 volts higher/lower than the rest then you may have a problem.
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im pretty sure it definitly is puffed. it is very squidgy (the pics dont really show it up), compared to the other lipo which is not squidgy at all. i'll see if i can hook up the battery just to find out the voltage, but id rather send it back and get a new one if i can. but since i am new to electirc im not really sure what is concidered puffed. because i think it is puffed but i could send it back and they could say its hardly puffed at all and get annoyed. how many more millimeters (approx) is a puffed lipo suppost to increase by? if that makes any sence lol |
It looks fine - I'd pop in the sack and charge it..
This is what a puff'ed lipo looks like! http://farm4.static.flickr.com/3146/...bd5b8e33b5.jpg |
If the cell is squishy and they will replace it; then get the replacement!
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yeah its nothin, ive shorted heaps of my lipos before with no ill effects. Not on purpose of course...except once lol This is why I hate people badmouthing them. Now we have someone who spent a fortune on lipos, afraid to plug them in for fear of blowing up the house.
Seriously dude, as long as you use a recommended charger theyre no more dangerous than any other battery. ive charged and run puffed lipos heaps, the performance is shitty but they dont explode unless you feel the need to stab them with a screwdriver or hook them directly across a car battery or something. And even then they just swell and catch on fire, no mushroom cloud explosions. |
At first when I heard of the pottential dangers of Lipos I was scared away. Then I seen some videos on YouTube!!! In order to get anything close to a spectacular explosion or fire you pretty much have to do it intentionally! like plugging the thing into AC or holding a dead short, or direct 12V hook up, but nothing was instantanious that I seen, it all took several minutes. I'm sure that it is frowned upon but I have fallen asleep many times with mine hooked up to the charger. It just shuts down to a trickle charge and the balancer keeps pulling little bits of juice out of it, after 6 hours it was no more charged than normal with no ill effects!
On that note I say get an RC vehicle going first run it a couple times and see what happens. Compare run times with your other pack, or if running in series check and see how balanced everything stays. I wouldn't jump to any conclussions just yet, no need to waste your money shipping and Neu's time disecting it if it turns out to be nothing! |
I ALSO PUFFED A 4S 5000 CRAPSAMPS PACK PRETTY GOOD BUIT AFTER I COOLED DOWN IT WENT BACK TO NORMAL AND IT WASN'T SQUISHY...SO I CHARGED IT AND BALANCED IT AND IT TOOK BACK 4700MAH AND HAS BEEN THE ONLY RELIABLE CRAPSAMPS PACK I'VE HAD...:yes: AND YES I'M STILL RUNNING IT IN MY 8IGHT WITH NO MORE PUFFING :yipi:
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My friend has a nasty puffed maxamps 2s 6000. His dean's plug couldn't be plugged in all the way, so it was backed out a little bit exposing the posts. During a race his wires flopped around and his deans plugs came into contact with a clip that holds his battery hold down on and shorted his battery. Not sure how long but it toasted the clip and his battery is fubar.
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if the battery doesnt charge up all the way, like if it only charges to 4700mAh rather than the full 5000mAh, thats not good because i have two of them to run in an e-revo, so I will need them to be both the same.
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Why dont you charge them and find out? Or I guess the first charge you wouldn't be able to tell. You could set your LVC higher than normal (say 3.2 or 3.3v) that should prevent the lower one (if there is one) from over discharging, then you can see if its significantly different voltage to the good one at the end of a run...
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the thing is, if i do charge it and something does go wrong, i can never send it back
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i dont think my hyperion duo charger is working right. the balancer works fine on the right hand side, but the left one doesnt work at all. i think its something to do with inside the charger, because i've swapped the taps and wires around and the left side still reads nothing.
o yeah and when i was looking at the voltages of the battery (3s), it was like 3.81, 3.81, 3.79. is this good? i decided to balance it anyway, so i hit balance and the fans came on immediately. it balanced it for about 20 seconds, then finished. the voltages for each cell was the same as before. does this sound right? how long should it normally take to balance? cheers guys |
.02v is pretty close - I think thats pretty much the tolerance for the balancer...
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That seems pretty well balanced to me. Even a balancer only balances to a certain precision.
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cool, well each of the cells look good then. maybe the puffing hasnt affected it. how do you calculate how much mah the pack has using the charger?
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Run the battery down and see how much you can put back in.
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you can only see how much the charger puts INTO the lipo, i.e. charge it up and it puts in 4700 that means it had 300 in it (just an example), it wont tell you whats there. Someone should make something that does though. well I guess thats where you go by voltage
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yeah i think its hard to accurately determine, but if you run it down to cutoff first then charge, you can get a better indication. still not perfect because chargers arent 100% efficient. the only real way is to have it charged then run it down to the cutoff, and measure the output of the discharge.
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It will always vary a bit from setup to setup and charger to charger. What you have the LVC set at will effect how much you can put back into the pack. A conservative (high) LVC setting will prevent getting the last drop out of your pack, but it will also help the pack last longer. Most damage is done to lipos in the last minute of discharge right before it dumps and it has a harder time holding voltage. I try and observe the rule of I dont want to run more than 85% of the juice out of my packs. I set the LVC a bit higher so when I hit the LVC on a 5000mah pack I would want to see the charger put back only around 4250mah or so and a 4350 pack only takes back 3700mah or so to keep it safe and make them last. Usually I find that the resting voltage is somewhere around 3.5v when they are at 85% discharged. Of course that will vary from cell type to cell type.
Being conservative with your LVC settings will help make your lipo investment last much longer and the minute or 2 you give up on runtime is worth it IMO. Also, if it is a damaged lipo or old it will have less capacity than when it was new. |
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