slashrunner

Is it a tell tale sign that lipos are at the end of their life when they get warm and puff after running them down to 11 volts?

I have a slash 2wd with a mamba max and 5700 motor geared at 14/86. The battery is a Turnigy 3s5000mAh rated at 20C-30C discharge.

Slo-V Flyer

Well that may be so, but usually it's from overheating too. How hot do your lipos get on average after a run? Do you check them often enough in between a few minutes?

slashrunner

They do get warm to the touch, maybe 100-110 but I don't have a temp gun. I should get one since they are only $25.  I never had them get warmer than ambient temperature before.

Slo-V Flyer

Then all I can say is that particular battery is fishy. There may be something else going on that I don't know.

slashrunner

Well actually I have two and both of them are doing the same thing. They did have a built in fuse that I had to bypass with copper wire. That's because a shorted motor burned out the fuse. I doubt that would be the problem though, If anything the shorting out probably did them in.

I'll try turning the power down in case my driving is too hard on the batteries.

JDenyer232

Ok, well I know your not gonna like what I tell ya but I would chuck them. If they were shorted even briefly then they are done, and a fire hazard as well. It doesn't matter if the short was in the motor or at the battery, a short is a short as far as lipos are concerned. Bypassing the fuse is not a good idea, the fuseis there protect the pack from shorts, they are not replaceable as it's a safety device that kills the pack to prevent further use.If you do keep them in service then I suggest you charge in a lipo sack and keep them stored there as well. Hope this helps.

slashrunner

I'm surprised they didn't have this problem 50 charges ago when they where first shorted.  As far as continuing to use them, whats the worst they can do, puff up and blow smoke.  The only time I've seen a lipo catch fire is when they are overcharged using a car battery.

kman8jr

My Feedback: (3)

DONT USE THEM OR CHARGE THEM ESPECIALLY IF YOU CHARGE THEM IN YOUR HOUSE =====DANGEROUS THROW THEM OUT< FOR YOUR OWN SAFETY!!!!!!!

SyCo_VeNoM

umm explode and burn your house down is the worst. Using damaged cells is not smart at all.

kman8jr

My Feedback: (3)

THATS WHY IM SAYING DONT LISTEN TO THEM JUST TOSS THEM IN A BUCKET OF SALTWATER!!REMEMBER SAFETY!!

ludeman

Ok, Im going to weigh in with my 2cents.
First it just sounds like what lipos do when they get old. Have you run them a buch of times? If so then it's pertty normal what they are doing! You can tell when a lipo is dying because it will still take a charge and even blanace but will not give the pop it used to. I have Lipo's that are years old and work fine, I also have some that give up the gost after 10 cycles. That is just the nature of them. I used to think it was just cheap'o china batteries but come to find out the name brands do it as well.
Second DONT JUST THROW THEM AWAY! They still have a charge and that could be bad. You should soak them in salt water for about a week. 1 cup of salt per gal. After a week or so of soaking they should be inert enough to throw away.
I have shorted my Lipo's before and they work fine. Have you ever seen sparks when you plug them in? That is shorting them! Yes lipos can be a fire hazard but I think it gets blown way out of proportion. I have never had a lipo go up on me but have had several NiMh's catch fire so they are a risk as well. We even shot a really bloated Lipo with a .22 right after running it and nothing happend.
The only time I have ever seen a lipo go nuke is when it's being charged and the charger is questionable. With modern computer controlled chargers it really is a lot safer.
I still recomend a safe place to charge them. Instead of a lipo sack I use a clay planter pot with a base, 5 bucks instead of 30 for a lipo sack.

slashrunner

I think they may be at the end of there life. I think they only have around 100 charges each at most but I'm sure being shorted out took a few hundred charges off there life. Right now Ive charged it up to full charge and then switched to charging at .1 amps.  The charger hasn't gained any ground over the past hour, I think it is loosing ground . curently at 12.50 volts and the bloating has gone down quite a bit, but I would say they are shot.

Any sugestions for the next 3s batteries?

kman8jr

My Feedback: (3)

I would say a turnigy 30c-40c because your battery couldn.t  handle your system.3-cell batteries of course for the crazy speed.turnigies are all i run.

slashrunner

wow, you read my mind on that one. I was thinking this one... http://www.hobbyking.com/hobbyking/s..._40C_Lipo_Pack

The most I have ever seen my system draw is 100A only because I use high grip truck tires. the way I drive almost makes that the continuous discharge lol.

kman8jr

My Feedback: (3)

I would get right on that because there is only ten in stock so you better hurry up and order that beast before hk is out for like a month.perfect batteryfor the application you are using it for.do you have youtube acount?if so why don,t you subscribe to my channel along with a friend invite so we could see some videos of mine and yours.go to losi 8ight-t 2.0 race roller in the search bar and you should see a truck with a blue motor and then click the video and go down just below the video screen and hit subsrcibe and semd friend invite for your future help on anything.THANKS!!!!!

Brainanator

My Feedback: (1)

there is actually 248 in stock...and that was a pretty lame way to get him to subscribe to your channel, why not just give him a link? lol

kman8jr

My Feedback: (3)

I just wasn,t thinking at the time because I,ve been answering all kinds of questions for at least 2 straight hours between him and another person.and there is actually 10 in stock if you look beneath the batteries stats you,ll see there is only ten in stock.

SyCo_VeNoM

Actually that is not shorting them hate to tell ya... Shorting is connecting positive directly to negative.
Sparks can be caused by it pulling power before you have the plug all the way in no short required, or even some contaminates on the surface of the metals conducting electricity. Go plug a line in your wall with a load like a vacuum cleaner turned on you will probably see it spark, now go cut a electric cord and touch the 2 wires together(or you can just take my word on this ) after its plugged in you will see it spark before your electric blows due to a short. You will notice the vacuum don't blow the breaker/fuse of the house but connecting the wire together does(unless you jammed a penny in the fuse box than your screwed)

BTW do the above experiment at your own risk

slashrunner

As far as the stock level goes, it depends witch warehouse you are looking at. The U.S. one has hundreds, wile the china one only has 10.

Brainanator

My Feedback: (1)

sigh.....If you look on the page, near the bottom, it says there is 10+ in stock (highly emphasize that +) If you add it to a wishlist, it will tell you EXACTLY how many are in stock, like I did to get my 248 in stock number.
I have included a picture of the wishlist with the stock status



There are now 243 in stock, as you can see, it is the last item in the wishlist.

If you don't believe me, do it yourself...
for the record, I am looking at this battery:
http://www.hobbyking.com/hobbyking/s..._40C_Lipo_Pack

Which I believe is in Hong Kong.

slashrunner

That's a nice thing to know, Thanks.

Brainanator

My Feedback: (1)

no prob

mrgoodbar

50 runs plus is really a lot of runs, but especially for the cheap HongKong Lipos. There is probably 3 or 4 active threads on this forum alone addressing the poor quality of the various HongKong Lipos. "You get what you pay for."


Lipo Do's and Don'ts

http://www.4-max.co.uk/pdf/dos-and-donts-lipo.pdf

slashrunner

I've herd nothing but good things about Turnigy and Zippy. sure you may get a bad one here or there but you can by four of them for the price of one of the name brand stuff. Mine would have lasted much longer if the bad motor and also a bad esc hadn't shorted them. I think It also had to do with the large current demand from the mamba.

since we are on the topic; Any ideas for installing a replaceable fuse between the battery and esc.

Brainanator

My Feedback: (1)

love it when people talk out of their ass