lipo battery charging troubleshooting...for my mini e-revo

[adeezy9183]

Ok so here goes. I finally broke down and got 2 lipo batterys for the little revo. They are 2s zippy flightmax 2200 mah. Anyways, I have a venom digital charger that can charge a bunch of different batteries. I soldered the traxxas high-current connectors to the new batteries and when I went to plug them up to the charger, it said connection interrupted. I know the solder job is good. The batteries are brand new. I use the same cable from the charger when I charge the ni/mh packs that came with it and it works fine. The same thing happens when I put the charger on balance and plug the cell-balance block into the battery. What am I doing wrong? Could I really have gotten 2 batteries that are both bad? These r my first lipo batteries so I don't know anything about them. I'm doing everything that the manual says....thoughts?

 

[slowngreen]

Make sure to have both plugs plugged in when your trying to balance it. Every once in a while I have trouble with a connection on mine even if the soldering is perfect, it can still not get a perfect connection for some reason.

 

[adeezy9183]

I have both plugged in. Both the traxxas connector and the balance connector. So should I try re-soldering it? I'm pretty pissed about it...both the batteries do the exact same thing. Wtf?!?!

 

[HPIguy]

I have both plugged in. Both the traxxas connector and the balance connector. So should I try re-soldering it? I'm pretty pissed about it...both the batteries do the exact same thing. Wtf?!?!

Are you trying to balance it, or charge it? Keep in mind, you can't balance a pack that isn't fully charged.

 

[slowngreen]

Hmmm, yeah resolder it and see what happens. Make sure you have your settings right too, maybe thats something its messing up on. If the nimh are still working with the same charge cable then its obviously not the charger malfunctioning.

 

[syphon68]

Should you have both the balance and charge connected at the same time? I normally charge mine through the balance tap so that is what is a lil weird to me.

 

[slowngreen]

On a Venom Pro, you must have both connected.

 

[adeezy9183]

Yea the venom pro is the one that I have. And it says connection interrupted when I try to charge it, discharge it, and balance it. And thanks for that tid-bit of balance info. I didn't know that u had to balance them when the batteries were fully charged...thanks. I'm gonna give the batteries to my buddy at work and have him re-solder them cuz he's real good at that kind of stuf...

 

[slowngreen]

I balance mine from a dead battery all the time on my venom pro.

 

[HPIguy]

I balance mine from a dead battery all the time on my venom pro.

Then I stand corrected. I was always taught you should balance a pack when fully charged. This way, you don't run the risk of ever dropping one cell below a safe minimum voltage. Again, this is just what I was told, maybe it's old school thinking, or wrong altogether.

 

[sweetdiesel]

Most balancers, (at least the ones I have used) do not allow a cell to drop below a minimum voltage which can be anywhere from 2.7 to 3 volts depending on the balancer. If you hook it up to a pack that has a cell that is below the voltage threshold, the balancer should come back with an error code/indicator.

 

[adeezy9183]

i guess when i get a chance ill try to resolder it.....i hope it works!!!!!! ooo the suspense!!!!!!

 

[adeezy9183]

ok so i've been reading up on anything i can find about the problems i am having and i read that you shouldn't cut the connector off by cutting both of the wires together, which i did. it said that this could cause a short. now how do i know if i did cause a short? what can i do? shouldn't the charger still pick up that the battery is connected even if their is a short? i think i'm going to take the battery to my hobby shop on monday to see what they can do. even if i did cause a short, they were both touching for less than half a second. as long as it takes to "snip" the wires with cutters.

 

[Metalhead Matt]

It's never good when a battery gets shorted like that. I've heard of the wires sticking to the snips from doing that. Very dangerous. Get a hold of a voltage tester and see where your at.

 

[slowngreen]

Like matt said, test it with a voltage meter and make sure you dont cut them like that anymore.

 

[adeezy9183]

ok yea i should've thought of that. should they read anything? cuz i haven't charged them or discharged them or anything... thanks guys. i'm new to the whole lipo side of things so i'm learning one step at a time

 

[Metalhead Matt]

It should read something. Most lipos get ruined when they're discharged all the way. Not sure what, but something around 7 volts would be in the ball park.

 

[adeezy9183]

ok from now on i'll cut them one at a time. tomorrow i'll check it with the volt meter and go from there. keep your fingers crossed.

 

[adeezy9183]

yea so i'm pretty sure that the batteries are fried. i resoldered them again and tried charging them and the charger still says connection interrupted on the both of them. haven't tested them with the volt meter yet but i'm positive that they're toast. lesson learned.......

 

[Metalhead Matt]

I'd test them for voltage before coming to any conclusions. Did they puff up or show any other sign of damage?