NEED HELP! Thunder Power 2s LiPo Dead Already?

[marauder]

My setup for charging includes:
2s 1320mAH Thunder Power LiPo
Dynamite 2-3 Cell LiPo Microprocessor charger.
Astro Blinky Balancer w/adapter for Thunder Power
Running this at 500mAH charge rate

First charge ran flawlessly, second charge much the same but with a lot longer charge time than I had expected. I ran yesterday for about 45 minutes on that charge and when I put it away it still had some juice in it. I did leave it plugged in as the same with my RC18, but when I plugged into the balancer no lights show. Plugged it back into the car and turned it on, nothing.

I tried to charge and nothing, the only thing I can get is the warning signal and it says it's supposed to do a low charge rate to bring it to a safe level. Frustrated not sure if it's actually charging I plug it back into the car and it did turn on for a few second and shut off.

I may just be extremely low voltage, but my ESC was set on Auto-LiPo detect and does function properly on both my Mini-T and RC18T.

The other LiPo for my RC18T will charge, will detect on the blinky, and will run my Mini-T so I'm almost positive it's the battery. I don't have a volt meter here handy it's in the shop, but I assume it's not a short in the wires because I did get the few seconds of power to the ESC when I hooked it back in.

I'm still trying to get this thing to do something, any tips would be GREAT!

 

[Mattyfats420]

did you set up the low voltage cutoff for the lipo according to the instructions with the brushless combo and through the castle link?

my guess is you dont have enough juice to get it going and the ESC is cutting it off

 

[marauder]

Yeah, I've got the ESC setup with the castle link for auto lipo. It ran fine last night but now nothing. I knew it was low and needed charging, but the charger will not let me charge it.

More than anything I don't understand why this charger isn't letting me at least gradually charge it. Now though, it does recognize when I disconnect it, but it it has been on this charger for an hour and still give me the warning thing when I try to charge it at 500mAH.

The instructions with this charger are bunk.

 

[Mattyfats420]

try charging at the next higher up charger. i think its not working cuz it doesn't have enough voltage to get the ESC to shut off the low voltage cut off which I'm pretty sure is 4V

 

[marauder]

If the ESC is set to Auto Lipo, then it wouldn't let the battery go lower than the safe voltage correct? If so, then even if running it until it's completely dead wouldn't hurt the battery? It wasn't dead, but I did leave it plugged into the esc. Maybe the ESC is bad? I have no clue, but I double checked to see if the voltage was set to auto lipo. Maybe shorting out that wire caused my problems?

Now I'm worried about my other lipo...

Is it safe to charge a 1500mAH at 1500mAH? The manual says so. I'm using the balancer while charging. I haven't had any problems out of this battery and it has about an hour run time. I have been running it until the ESC shuts it off. Is that not safe? I really don't know how else to tell the LiPo is low on charge because it runs full out until it stops basically.

 

[marauder]

Anyone?

 

[marauder]

Wow, no responses...


Anyway, bought a new Losi 1650mAH 2s lipo. Decided I would take the other LiPo to the garage and experiment with a cell phone charger to bring the voltage up to 6.6 so that it would safely charge. I do not recommend this at all, but it worked. I'm charging the Thunder Power now and it's balancing correctly. EVERYONE told me that I had to buy a new LiPo but considering everyone in my family are electrical engineers we were able to do this safely and it's working great.

 

[CharliesTheMan]

I've heard from several people who have done similar things. Apparently once the voltage drops below the safe zone, the computer in the LiPo charger doesn't recognize the battery. If you can safely bring the voltage back up, the computer will recognize it. Now here's what's important, you need to set your voltage cutoff so that it doesn't happen again, instead of relying on the auto mode. It will only take 20 more seconds to do it right.

 

[marauder]

Set it at what voltage for a 2s? 6.0? I have my castle link hooked up now making some changes, I was under the assumption that I was using the best setting. I will change that now.

It actually went below because I left it plugged into the esc overnight. I will try not to be in such a rush anymore and unplug them after use.

*Edit

3v per cell. 6.0 Volt for the 2s, but should I set it to something like 6.2-6.4 to be safe?

 

[robmob]

You should never leave a lipo pack connected to an esc while it is turned off. Juice will still be drawn out of the pack until it is dead. The cutoff on an esc does not work while it is off.

Sounds like you drained the pack completely and it is done.

If you have a volt meter, use it to check the voltage in the pack.

 

[marauder]

You should never leave a lipo pack connected to an esc while it is turned off. Juice will still be drawn out of the pack until it is dead. The cutoff on an esc does not work while it is off.

Sounds like you drained the pack completely and it is done.

If you have a volt meter, use it to check the voltage in the pack.

Well, I've learned my lesson there. Fortunately I was able to revive the pack. It's about to finish it's charge in a few minutes. I won't know for sure if it's still good or not until I run it a few times, but at least it let me charge it now.

I have my volt meter handy now and I'm watching the voltage while charging to make sure it's safe.

What is a safe voltage cutoff to run? The paperwork says do not charge if it's below 6.6volts, should I set the cutoff there?

 

[robmob]

It is 3V per cell.

If your paperwork on your 2 cell pack says 6.6V, then I would use that.

 

[flm_savage]

Set it at what voltage for a 2s? 6.0? I have my castle link hooked up now making some changes, I was under the assumption that I was using the best setting. I will change that now.

It actually went below because I left it plugged into the esc overnight. I will try not to be in such a rush anymore and unplug them after use.

*Edit

3v per cell. 6.0 Volt for the 2s, but should I set it to something like 6.2-6.4 to be safe?

i haven't read to the end yet but when i read that your low voltage cutoff was 4V, i thought about what you said in this post. For my 2S lipo, i set the cutoff at 6.5V I don't care to push the envelope for low voltage. at 6.5 i get tons of runtime and the peace of mind that i will never go too low with it.

 

[marauder]

Yeah Kurt, actually I was using the Auto LiPo setting on my castle link. Not sure where you seen 4v. I'm thinking that 6.6V is a very safe number for my 2s lipos. Besides, I have 2 for my Mini-T now!

I've been doing a lot of reading today and trying to learn more about LiPo. I hope soon I will be the one answering questions, not asking them. I felt like such an idiot doing what I did, but we can all learn from our mistakes.

 

[flm_savage]

i saw it in matty's second post. I'm not sure what the stock cutoff is on the mamba stuff but i know its not 6V. Glad you got it going! Lipo ROCKS!!!!!!

 

[marauder]

You aren't kidding, and hats off to both you and robmob for both being able to set up drivetrains that can handle serious power. Neither have even so much as hiccuped on me yet, though the RC18 is prone to tiny rocks getting into the spur gears and making a lot of noise.

And another big thanks to Matt for hooking my Mini-T up with brushless.