Hello Everyone! MY SC and questions :)

[flydiver]

www.allaboutcircuits.com/vol_1/chpt_3/9.html

or google
[how to use a digital multimeter]

Lot to learn in the sport, eh?

[pauliepilot]

Yeah loads of information you need to remember there are so many settings on this multimeter!
I'll get there in the end

[flydiver]

Mostly you will use it very simply - DC voltage for battery checking and Ohms for checking for shorts.

You WILL need to check for shorts. You WILL have a motor you try to start and it will shudder/stutter/jerk and NOT run. This is a function of a broken wire, bad solder joint, or other bad connection. Very common problem, esp. with cheap motors.

BTW-If that happens to you STOP IMMEDIATELY! Do NOT try to force it to run. You will burn out your ESC. Guys have burned out all their ESC trying to make a bad motor run and then end up wondering if they have a bad motor or bad ESC. Now they have both. Makes trouble shooting challenging.

[pauliepilot]

Im not even sure that it works?i'l test a batt and dont get a reading on dcv and dca set to 20/20m?
Waste of £5.....its a amtech dt830b looked all over to try and find how to use it.
Im just getting more anoyed now i have one n cant use it???

Turns out i had a faulty meter got a new one now that works....so to test how much voltage is on my lipos do i set it to dcv at 20 then pos to pos neg to neg?or test through the charge plug!

[flydiver]

Set to dcv 20 (higher than you intend to measure).

You should have some pointed probes and just connect the red (+) to same, and black (-) to same.
Test it on a simple AA or similar first.
That gets you total battery voltage.

DO NOT SHORT THE PROBES WHILE DOING THIS!!!! Sparks and bad nastiness will happen.

Measure 1&2, 2&3, 3&4 wires at the balance tap. That will give each individual cell.
DO NOT TOUCH THE PROBES TOGETHER - SHORT! BAD!!! The probes are quite close together and it's easy to do.
You should get all cells above 3.0v. Fully charged should be 4.1-4.2v/cell.

Note - you may have a couple options on where the probes plug into the meter itself. You'll have to refer to the instructions on that meter. Usually one position does volts and ohms, and the other does current. You CANNOT easily do current with these cheap meters without a bunch of modifications.

[pauliepilot]

Thanks now i no,the one 1000ma pack has been shorted has a a tiny burn hole it happend when i pushed it in to the batt conpartment on the sc lp...as i remember the tail n rudder went full right n up?some think wrong sumwhere!
When i bought my p3 p40 i got a dx6i and i now use this radio with sc lp,but allso have another sc that im going to put the rtf bk into maybe sell!

Iv just tested that one pack on the balance tap :-)
From black side 4.01v....4.12v.....4.13v so iv damaged the end one???

[ginginho]

Dec 14, 2010 13:02:01 GMT 1 pauliepilot said:

Iv just tested that one pack on the balance tap :-)
From black side 4.01v....4.12v.....4.13v so iv damaged the end one???

If these were measured between the pins as Fly listed, then it doesn't look like any cells are damaged but the first listed is out of balance.
If you have a decent charger (i.e. Not the HZ one) try a balance charge and check the cells again once it's finished. It might get closer to the other two. Monitor it over the next few uses and see if that cell always goes low before the others. If so, it's not in the best of health, if not, it's fine.
For cheap (and good) Lipos, check giantcod.co.uk, about the most competitive in the UK.

[flydiver]

The one cell is somewhat out of balance. That could be a individual cell issue, a charger issue, or both.
As suggested, you now have tools to monitor. Check the overall voltage and individual cells after flying. They ideally should all be at least 3.5v or better. It is not unusual for cell balance to get worse when discharged but should balance back up when charged.

Maintaining balance is one of the desirable characteristics of better cells. Really good cells often don't need balancing, they just stay in balance. It wasn't all that long ago that lipos were not balanced at all and chargers did not have that option. They also were a LOT more expensive, the cells were hand picked for the pack, and the C-rating/performance was a LOT lower.

[pauliepilot]

We have come a long way since....with the 2.4 radios brushless motors/esc.
But nxt on my list is a charger,im going to check them all nxt time i fly...iv broken one of the control conecters
will have to get some spairs :-(

[pauliepilot]

I have retired my yellow soler film sc after takeing it to my lhs and weighing it.... a 25g sc??? amp tested in shop showed 18amp draw

I have a sprayed sc...all work done ready to fly when the snow stops! :-(
Allso i picked up a fusion ethos lx41b least its betta then the hz one.