Having some charging issues... - RC-Monster Forums

HummerMan · **Having some charging issues... -** 04.20.2007, 08:36 PM

Ok, I will start off and say I have a SuperBrain 989 charger, Hyperion LBA10 Balancer, and MaxAmps 8000mah 2s Lipo. I've already ran the battery in my Mamba Max 5700 Rustler. I tried charging once I had all the wires soldered up and it told me it was fully charged in a few minutes. I ran the truck til it stopped. Had the cut off at 6 volts, as per MM's instructions. But I can't get it to start recharging. It tells me the polarity of the battery is backwards, and the volts are to high. Am I missing anything? Thank you for any and all help!

BrianG · 04.20.2007, 09:03 PM

OK, first of all, do you have any clear pictures of the battery (especially connections), wires, and charger/balancer hookup?

The charger saying the polarity is backwards is odd if the wires/connectors are hooked up right.

This might sounds stupid (and please don't think I'm trying to be funny), but are you sure it is 2s and not 3s or something? Also, are the settings on the charger set right; like # of cells, charge current, and battery type? Can you get a picture of the screen of the charger like you had it set?

HummerMan · 04.20.2007, 09:05 PM

I will get you some pics here shortly...

HummerMan · 04.20.2007, 09:17 PM

Ok, here are some quick pics....

BrianG · 09:45 PM

OK, looks like you have all the Deans hooked up right. How about the little green connector on the charger? Are the + and - wires in the right slots on there?

Also, you do know that you have to press the button on the balancer right? Solid LED means it is in "stand-alone" mode. Blinking means you can charge/discharge.

HummerMan · 04.20.2007, 09:48 PM

04.20.2007, 09:45 PM

Did you run the truck until it just wouldn't go any more, or did you run it until the LVC reduced the power to the motor? If you ran it until the battery just didn't have enough juice to move the truck anymore, you may have overdischarged the battery. If the battery is overdischarged and you try to charge it, the low voltage will confuse some chargers and freak them out. If you have a dmm or voltage meter, check the voltage of the pack.

I've seen this issue with a couple of chargers where a battery that is under voltage confuses the charger. In this case, and under voltage battery will have voltage too low to be read as a 2S pack, but the voltage is too high for it to be a 1S pack. The charger can't decide what to do and freaks out, then gives its default error, which is a polarity error.

I don't know if the 989 will act this way. It's just what I've seen a couple of times.

Try doing a passive balance on the pack first. Then see if you can get the charger to charge without the balancer in line.

HummerMan · 09:51 PM

Quote:

Originally Posted by AAngel

Did you run the truck until it just wouldn't go any more, or did you run it until the LVC reduced the power to the motor? If you ran it until the battery just didn't have enough juice to move the truck anymore, you may have overdischarged the battery. If the battery is overdischarged and you try to charge it, the low voltage will confuse some chargers and freak them out. If you have a dmm or voltage meter, check the voltage of the pack.

I've seen this issue with a couple of chargers where a battery that is under voltage confuses the charger. In this case, and under voltage battery will have voltage too low to be read as a 2S pack, but the voltage is too high for it to be a 1S pack. The charger can't decide what to do and freaks out, then gives its default error, which is a polarity error.

I don't know if the 989 will act this way. It's just what I've seen a couple of times.

Try doing a passive balance on the pack first. Then see if you can get the charger to charge without the balancer in line.

And I'm going to assume thats a very bad thing.... I had the MM set up to shut the truck off at 6 volts. 3 per battery, right? The truck died quick. It would accerate then nothing. I couldn't give it more throttle or anything. The truck wouldn't react. Then in a few seconds later I could give more throttle. But then it would stop....

Brian, I've tried charging it with and without the balancer, with the light solid and flashing... Nothing

BrianG · 04.20.2007, 09:50 PM

Thanks for the pic. It looks like all your connections and charger setup controls are prefectly fine.

Like AAngel said, what voltage is the pack (and measure each cell through the balancer if you can)? I didn't even think of an over-discharged pack - although you'd think it would say "voltage too low" if anything...

And what about what I said about the LBA10? Did you try pushing the button so the LED blinks?

BrianG · 04.20.2007, 09:52 PM

Overdischarging can ruin a lipo, but it sounds like the LVC is working OK. For a little extra insurance, I generally set my LVC for 3.1v/cell (6.2v for 2s), or even 3.2v/cell through the MM computer software.

HummerMan · 04.20.2007, 09:53 PM

Ok, I will raise it to 6.2 volts.

BrianG · 04.20.2007, 09:57 PM

You do realize that setting it to 6.2v will reduce runtime slightly (probably less than 30 seconds)? Generally, you set the LVC so that after you have the pack disconnected for about 20 minutes, the voltage rises back up to ~3.5-3.6v/cell.

Also, try it without the balancer at all. Just hook the pack up to the charger directly.

HummerMan · 04.20.2007, 09:59 PM

I thought you didn't want the pack to be ran down below 3.0 volts per cell. So is that for the whole pack or just one cell? MM recommended that I had it setup at a 6 volt cut off. The truck ran awhile, wheelies etc.... Then died suddenly. But why won't it recharge. I don't have a way to check the volts of this battery atm.

BrianG · 04.20.2007, 10:02 PM

That is true, but sometimes lipos may not bounce back as much. It won't hurt to set it to 6v (3v/cell), it's just that a slightly higher setting is better for the battery.

Did you try charging without the balancer?

HummerMan · 04.20.2007, 10:03 PM

Yep, still does the polarity/high voltage issues....