Having some charging issues... - Page 2 - RC-Monster Forums

04.20.2007, 10:06 PM

I set my LVC for 3.2v per cell. 12.8v for a 4S pack. My thunderpower charger assumes that a lipo under 3.2v per cell is overdischarged and charges at a low rate until the voltage gets up to what the charger thinks it should be.

Try setting the charge rate to .5A and see if it will start charging. If it does, let it charge like that for an hour or so. Lipos generally hold their voltage very well and, although 3v per cell is supposed to be the safe limit, getting the pack to 3v per cell means that you really drained the battery.

BrianG · 04.20.2007, 10:06 PM

If you measure each cell and each cell is >= 3v, then it's gotta be a bad charger...

Do you have any other chargers you can try?

BrianG · 04.20.2007, 10:08 PM

Quote:

Originally Posted by AAngel

I set my LVC for 3.2v per cell. 12.8v for a 4S pack. My thunderpower charger assumes that a lipo under 3.2v per cell is overdischarged and charges at a low rate until the voltage gets up to what the charger thinks it should be.

Try setting the charge rate to .5A and see if it will start charging. If it does, let it charge like that for an hour or so. Lipos generally hold their voltage very well and, although 3v per cell is supposed to be the safe limit, getting the pack to 3v per cell means that you really drained the battery.

Usually, the pack drifts back up to something higher than 3v/cell.

If Lipo mode doesn't work, I wonder if he could use NiMH mode at 0.5A for like 5 minutes. Then try Lipo mode again.

HummerMan · 04.20.2007, 10:11 PM

I don't have any other Lipo Charger to try... And it won't charge at .5 amps either. Same stuff....

BrianG · 04.20.2007, 10:12 PM

OK, try charging in NiMH mode: 6 cells and 0.5A for 5 minutes. Once the voltage gets to 7v, stop the charge and try Lipo mode again.

HummerMan · 04.20.2007, 10:14 PM

Is that safe? <<< Honest question, electric newb.

04.20.2007, 10:16 PM

hummerman,

the big deal about lipo is that you don't want to over charge them or drive too much current into them. What brian is proposing won't result in either.

Do you know for a fact that the charger works?

HummerMan · 04.20.2007, 10:17 PM

Keep the same 8000mah rating? Balancer or not?

BrianG · 04.20.2007, 10:17 PM

Well, you don't want to do this all the time, that's for sure! Basically, doing this will eliminate the lipo safety checks. If the voltage is too low, then this will get it just high enough to get the cells back in the 3.2v/cell range. Lipos are charged initially in constant-current mode, which is what NiMH mode uses.

If you want to do this, but be VERY safe, use 6 cells and 0.1A for 1 minute. Watch the charge voltage. Once it gets to 7v, stop the charge and go back to the normal lipo mode.

No balancer. And you can set the mAh rating to 500mAh.

HummerMan · 04.20.2007, 10:19 PM

I get the same error yet....

BrianG · 04.20.2007, 10:21 PM

So, NiMH mode got you to a decent voltage and then when you switched back to Lipo mode, it still gave you errors?

04.20.2007, 10:23 PM

Do you have another pack, lipo or nimh, to try on the charger. All of your connections look good. Did you do all of the soldering yourself? Did you check for cold solder joints on the connectors?

HummerMan · 04.20.2007, 10:24 PM

I just tried a different battery. A 1100mah 5 Cell RX pack and the same errors come up. So I guess I need to figure out whats wrong with the charger. Any ideas lol? Thanks guys!

BrianG · 04.20.2007, 10:26 PM

The charger is "bad", lol. Seriously, it sounds like you'll need to return it. Did you get it locally?

10:28 PM

It isn't outside of the realm of possibilities that you just got a bad charger. If you are running it with the power supply, try running it off of a 12v source, like a car battery or something.

Does your charger have a reset button or anything? Make sure that the charge lead doesn't have a short in it. Maybe a loose strand or something.