Super Brain 989 - Over Heat On Discharge

[ANGRY-ALIEN]

Hi all... I am having a little trouble with an MRC 989.. The unit is pre-owned and I got it off ebay. So far I have been able to discharge and charge three sets of 16 cell packs
with no worries. On the fourth set I noticed that the charger had cut out a little early in the discharge mode and the cells still had a little bit left in them. I restarted the dis-charge
and few moments after it shut down again with the voltage per cell way above the target I had set (.4 per cell - not sure if that is right now)...

Then I noticed that the temp of the charger went up a bit when I started the dis-charge... It had gone up to 155° with the the internal fan going in two and a half minutes.

Set up was:
MAH -3300 is set for that profile (it only removed 130 mah).
Cut off V - 0.40
AMPS - 5
Number of cells - 12

For some reason it does not like me setting up above 2 amps... Though even at two amps it looks like it's shutting down pre-maturely. When I gave up on the discharge mode,
I tried charging at 5 amps (since this thing is rated for 10), it do not go past 300 mah. The temp had gone again.

set up for charge:
12 cells
3300 mah
4.5 amps
Trickle - .35 amps
Cut off temp - 136° (for the batts)
Cut off peak m V - 5

Has anyone seen this kind of problem before with this charger? any advice/help with be appreciated.

Alien

[bdebde]

I notice mine gets quite hot when trying to discharge so I don't do it with that charger.

[wallot]

I would check the fan, it might be worn out, dusty. never had any temp issues with my old 989.

[BrianG]

12 cells at 2A is ~24 watts. It's gonna get warm. My Hyperion EOS 7i does that too - gotta remember it is converting all that energy to pure heat. Also, you might be hitting a power limit. My Hyperion has a 20w limit, so the higher cell counts I go, the less current it will discharge at.

[ANGRY-ALIEN]

Originally Posted by bdebde

I notice mine gets quite hot when trying to discharge so I don't do it with that charger.

Hmm.. I do have another charger, but it will only facilitate 15 cells at a time. I would have to revert to single pack discharging.

Originally Posted by wallot

I would check the fan, it might be worn out, dusty. never had any temp issues with my old 989.

I'll check the fan later tonight... To be honest, the fan on the power supply was filthy and I had to remove it and clean it before use.

Thanks for suggestion wallot.

Originally Posted by BrianG

12 cells at 2A is ~24 watts. It's gonna get warm. My Hyperion EOS 7i does that too - gotta remember it is converting all that energy to pure heat. Also, you might be hitting a power limit. My Hyperion has a 20w limit, so the higher cell counts I go, the less current it will discharge at.

do you have any recommendations Brain? like a basic setup for discharging and charging... I am currently running 3 sets of 16 cell packs and a 12 cell pack (all have cycled up to an average of 3200 mah)

Thanks for the quick response guys...

Alien

[BrianG]

How about a discharge tray?

Or a set of power resistors mounted to a large heatsink and fan (yes, fans are ok here because it would be on a stationary surface).

Or a set of 12v car bulbs in parallel to get the amperage load you want.

You'd have to be careful with these solutions to keep the pack from draining too far if left unattended.

[ANGRY-ALIEN]

Cool Brain.. I will do some digging with these options in mind.

Thanks
Aline