Is my battery toast?

[Bliss_RC]

Boy am I failing hard at this new RC hobby...

So, I got my bomber a few days ago, didnt put my battery on the charger first and put it in the car. I ran it for maybe a total of 20 minutes, just testing things out. I have the duratrax onyx 255 charger and I wanted to see what my volts were at each cell. In order to do that, you need to start a charge. Well its giving me an error, which i found that I may have over-discharged the battery on accident. Its showing 8.91v total output on a 3s battery, so that means its at 2.97v per cell (if theyre all the same). Did I totally ruin this brand new battery? Is there a way to fix this or am I screwed? Appreciate your help...

[TheLetterJ]

You can give it a "bump start" by setting your charger for a NiMH battery. Let it charge to +/-10v and then restart on a LiPo balance charge. I wouldn't make a habit out of it, but that should get you going.

[Bliss_RC]

Originally Posted by TheLetterJ

You can give it a "bump start" by setting your charger for a NiMH battery. Let it charge to +/-10v and then restart on a LiPo balance charge. I wouldn't make a habit out of it, but that should get you going.

thanks I just spoke with a friend and that was his suggestion, but now I'm wondering if my charger is even working properly, because i cant seem to get it to charge in any state. I'm gonna take the battery and charger down to my local hobby shop and hopefully they can help me figure this out.

Also, I noticed in the manual for the bomber that the factory esc comes with a lipo cutoff turned on. This should've prevented my battery from being over discharged, no? I'm trying to figure out at what volts it would cut it off though...not saying in the manual.

[TheLetterJ]

There are "jumper" plugs on the ESC, make sure it's in the "Lipo" slot. That said, my old Wraith Spawn's AE5 ESC (should be the same as your's) did not shut down before roaching a battery either. Now, I can generally tell that the performance is dropping off before the lvc kicks in, and I usually wouldn't run it long enough for my 5000mah battery's voltage to be a concern, but the one time I did (letting all the kids take turns), it dropped down to less than 3v per cell before I heard "Dad, it won't go!" I gave it the nimh trick, and that battery lived a long life (over 2 years.) I ended up running a lipo alarm plugged into the battery's balance plug on that car.

[mikemcE]

Yep, but some chargers won’t let you do that.
I did use an older charger, brought the cells up to 3v each, then regular balance charge.
On my esc, I set the cutoff voltage at 3.4v seems too work well


Hang up and Drive

[Greatscott]

Originally Posted by TheLetterJ

You can give it a "bump start" by setting your charger for a NiMH battery. Let it charge to +/-10v and then restart on a LiPo balance charge. I wouldn't make a habit out of it, but that should get you going.

This works, but be very careful when you do it. Pay very close attention to the charger when you bump the pack, and for the next couple charge cycles.

Generally battery charging should be treated like the ocean, never trust it, and never turn your back on it...

[Bliss_RC]

So I just got back from my local hobby shop. Something really funky is going on, and they think the battery is no good. They tested the battery and it showed 4.2v, 3.8v, 3.8v....so I did not over discharge the battery. It was weird that the one cell wasnt discharging. So we put it on one of their fancy chargers and it did charge/balance it. We then put it in a car and ran it for about 10 mins. We then checked the voltage per cell and it was 4.05, 4.05, 4.00. We thought we figure it out. Tried to put it back on my charger to see if it would charge, and it gave us the same error. We then tested the cells and it came up 4.2, 3.95, 3.95. Something with plugging this battery into the charger I have is making it do that. BUT, we plugged one of their batteries into my charger and it started charging just fine. I'm going to call tower hobbies and see if they will send me a new battery or help me out here.

[nightcrawler48]

The Axial AE-5 lipo low voltage cutoff is set at 3.7V per cell, 11.1V total for a 3s.

[Hydrocarbon92]

Sounds like the battery's balance lead doesn't like your Onyx, if other batteries are working & giving under-volt error when it's fine. It's just odd your battery works fine on their charger and your charger works fine with their battery.

[Bliss_RC]

Originally Posted by Hydrocarbon92

Sounds like the battery's balance lead doesn't like your Onyx, if other batteries are working & giving under-volt error when it's fine. It's just odd your battery works fine on their charger and your charger works fine with their battery.

Yeah I know right? At this point I just want to return both and then get a new charger/battery setup from my local hobby shop. Its weird too because this was bought as a "package" with my rtr bomber from tower hobbies.

[Bliss_RC]

I FIGURED IT OUT!!!!!

So, the problem was the battery leads connector to go from the charger to the battery pack. My charger came with two sets of leads with two different plugs. I was using the the t-plug that the axial comes set up with. Good thing is the venom plug has a universal type setup so you can change the plug to whatever youre running. I had a thought, let me try the other lead to see if maybe something is wrong with the lead.....so i swapped plugs and BINGO! CHARGER WORKS!! I took the cap off the t-plug to inspect the solder job and it looks like the positive wire has a pretty sketchy solder job. SO, I'm going to re-solder that one wire and see if it fixes it. If not, then I will cut the t-plug off that set of leads and solder it onto the one that I know is good.

Bottom line, is I got it all figured out and I'm not having any more issues with it! Very happy I got it all straightened out. Now i can have some fun with this thing and do some bashing on christmas!!