puzzled

[stu]

So this past Christmas i get a DX6i radio. Over the winter i take my time and install the radio, esc, servos, and aileron mod. Test it out at home and everything seems good.

Yesterday i only grab the 8 cell battery and stop the park for a quick flight before work. I was lucky to get 10 feet before low voltage cutoff and she set down on the field. I forgot this battery was giving me trouble while i was setting up the esc/receiver; so i brush it off and think the pack is going.

Today i took the 7 cell battery with me to the same park. This time i was lucky to get 5 min of flying before the low voltage cutoff.

So does anyone have any ideas what might be causing this?? Can it be possible that two battery packs are going (even thou they are less than a year old)

Here is my setup:
- Stock motor and prop
- Telebee 20A ESC www.flyingsites.co.uk/shopfront/telebee.htm
- Hs-55 Servos
- AR-6200 6-Channel receiver
- HobbyZone batteries 7 and 8 cell
- Car charger that came with SuperCub

Thanks
Stu

[sayers]

Hi Stu
Do you have a multimeter ? Check what you voltage is in the batt off the charger . The 7 cell is a 8.4 volt batt should read 10+ off the charger. Maybe the charger is not working .
Other than that , I being new at this don,t have a clue as to what it might be But one of the experts on the forun will no doute jump in here and give some ansewers.
Happy Flights & Soft Landings
Sayers ( Jerry )

[SCC]

Hi Stu.
I assume your NiMh's have been charged recently?

Also check your LVC jumper has not come out.



BTW. Welcome to the forum.

[sayers]

Hi Stu & SCC
SCC he is using a AR6200 RX That don't have that jumper . Does it ?
Stu I posted the wrong voltage Should be 9+ off the charger.
Happt Flights & Soft Landings

Sayers ( Jerry )

[flydiver]

Apr 18, 2008 21:11:35 GMT 1 stu said:

So this past Christmas i get a DX6i radio. Over the winter i take my time and install the radio, esc, servos, and aileron mod. Test it out at home and everything seems good.

Meaning you didn't use them since Dec? NiMh can lose 1-3% of their voltage/day. In 3 months they are almost > completely dead. If they are are year old and suffer this kind of neglect they may....or may not....recover.

Do a slooooow discharge (very low speed) and then a slooooow charge. A couple rounds and they may recover. If not, they got hosed.

Unfortunately the use of a multimeter to check voltage on rechargeable is mostly really crude and highly inaccurate. They have to be under LOAD. I have several almost worthless NiMh that read full voltage when resting but don't run worth s**t. They sag terribly under load. A wattmeter or the like work best, but just fire up a charged one on the plane and if it doesn't run strong it isn't doing the job, something is wrong.

fly

[stu]

Sayers i do have multimeter and i will quickly check the voltage

SCC Stock electronics are all gone mate and i don't notice a jumper on the esc

Flydiver I was lucky enough to get some flights in this winter (i have the frozen fingers to prove it ;D ) and did cycle the batteries at least twice at home. Winter started early and they did sit for some time. My brother has a good charger so I'll get the batteries up to him and see if that helps out.

BTW how many watts should the motor be pulling??

also thanks for the quick replies

[SCC]

Apr 19, 2008 3:01:45 GMT 1 stu said:

Sayers i do have multimeter and i will quickly check the voltage

SCC Stock electronics are all gone mate and i don't notice a jumper on the esc.

My apollogies. Your first post clearly states that you changed your electronics. What was i thinking, LOL

Anyhow. Sounds like your NiMh's need a good charge.

[stu]

no worries... just glad you could help a nub out ;D

so it looks like the car charger is toast or at least i think it is (I'll get some voltage measurements later to confirm it)

I did as SCC suggested... a nice sloooow charge; followed with a slow discharge (2A seemed slow enough).

While charging i measured 11VDC on the terminals. Once it was finished i dropped the battery in the cub and measured 8.5A at full throttle (4.5A half)

BTW this was all done on my 8 cell (9.6V) pack. I'll test out the 7cell (8.4V) pack later today.

Thank you for your help.
Stu