eepers

So, I'm neck deep in frustration right now, maybe someone can tell me where I'm going wrong (or at least put in a bid on some rc plane stuff, haha).




Here's some background info.

I have a GWS peak charger (the mc-2002 featured below)

[link=http://www.ozeflight.com.au/category52_1.htm]charger info[/link]


I have a 7-cell 8.4V/600mAh NiMH battery, and an 8 cell 9.6V/700mAh NiMH battery.

I have a GWS ICS100 speed controller as well as a GWS ICS300E controller.

I'm powering a GWS 300 speed motor.



So, that's out of the way, here's my problem... I'm getting full throttle run times of about 30 seconds with the 8.4V battery and the 9.6V does entirely funky things (when revving up it cuts out at higher throttle, and continues to drop out earlier and earlier each time I ramp the throttle up.

I generally plug in my batteries, tweak the current to about 1 amp on the charger's display, and leave it till the green trickle light comes on and the current drops. That means it's full, correct? I run the charger off an extra motorcycle battery I have.

Is there anything basic I'm missing here that I can slap myself on the forehead for?

shams42

My Feedback: (1)

Which ESC are you using? If you're using the 100, maybe you are exceeding the amp limit of your ESC.

Matt

eepers

I'm using the 300e now.

Hmmm... maybe I should hold off on the doom and gloom. Tonight when I charged the 9.6V and put it in, it did get all the way up on the throttle but I'm afraid I'll annoy my neighbors if I power it up to see how long it'll run, hahah. (it's nightish already)

So... I suppose this begs the question, "is there a break-in period for things like batteries and controllers and motors? If so, which ones, and how do you warm'em up?"

sierra gold

There is no "break in" for the ESC. I don't "break in" my GWS motors and they run fine. (Others may disagree. )

NiMh batteries will improve after about 5 charges/discharges. I just fly my packs from new and expect slightly shorter run times for the first few flights.

Sierra Gold

loading

Is it a new pack? Is so, you need to charge it slow for the first few times. I have the same charger, I use it to charge new packs all the time. For the first few charges, I turn the current down as far as it will go. Then I after its done charging, I let it trickle charge for another 12 hours.

Matt Kirsch

My Feedback: (21)

Part of the problem is, you're charging the batteries too fast, and the peak detect is kicking in long before the battery is charged.

1 Amp is far too high for either of these batteries, especially when new. For most NiMH, you do not want to exceed "C" when charging. C is the capacity of the pack in Amps. A 600mAh pack has a C of .6 Amps. A 720mAh pack has a C of .72 Amps. For bonus points, what is C for a 3300mAh pack?*

The charger is probably dropping into trickle mode within the first 10 minutes... That's a sure sign the battery is not being charged properly. Charging at the C rate should take about an hour if the cell is fairly well discharged.

Another possible issue here is that the motor is drawing more Amps than the batteries can produce. Running a GWS 300 motor on their 600mAh and 720mAh NiMH packs is borderline. Well-seasoned packs are pretty well maxxed out at full throttle. New packs might be a little overtaxed, but they will get better with GENTLE use, a few cycles.

*If you said, "3.3 Amps," you are correct

eepers

yeah, both new packs. Wow, as low as it will charge for 12 hours eh? OK, I'm game for that. haha, I thought 1 amp *was* low yes, the trickle kicks on much less than 10 minutes in, so I'm sure you guys are spot on the money.

Excellent info, thanks so very much guys!