LiPo battery charging and the USB provided charger

[Michael Fenimore]

Firstly, if this is in the wrong place, please move it.

My subject is kind of broad. Here's my situation; My Syma X5C-1 USB battery charger seems to be failing. In the beginning, about 15 or 20 charges ago, it would charge the battery and shut off the LED to indicate it was done.
Now, the past 3 charges, the light stays on for about 5 hours or more.
I allow the battery to reach room temperature at all times before charging. Rest periods after flights is never less that an hour.
Anyhoo...
Today I pulled out my iMax B6 charger. Plugged in the battery, set all parameters (.5A, 3.7v) and started a charge cycle. The battery charged to 4.2 volts and .5A as expected in about 54 minutes.
DVM shows 3.9v 30 minutes after charging. So I'm going to guess (and cross my fingers) that the battery is still OK but the USB charger is being erratic.

I have other batteries on order, but they seem to have found that proverbial "slow boat from China."
They should be here next week.

So, am I doing this right? Should I consider using the iMax B6 to charge all my batteries?
Any input is greatly appreciated.

Your noob in service,
Mike

 

[Jackson]

Plugged in the battery, set all parameters (.5A, 3.7v) and started a charge cycle. The battery charged to 4.2 volts and .5A as expected in about 54 minutes.
DVM shows 3.9v 30 minutes after charging.

Well .5A sounds a little high for a single Syma battery. Did you meter it right off the charger, as 3.9V after a rest seems a bit low.

 

[Michael Fenimore]

Well .5A sounds a little high for a single Syma battery. Did you meter it right off the charger, as 3.9V after a rest seems a bit low.

The battery is rated at 500mah, hence the reason for setting at .5A.
If you're asking did I measure right after charging, yes. 4.14 volts then after 10 minutes or so the 3.9v reading.

 

[Jackson]

so the 3.9v reading.

That means you will start your flying at only at about ~75% capacity of the battery. Try metering a battery right after a flight and see what you get.

 

[Michael Fenimore]

Wasn't able to fly much yesterday due to high winds.
Today looks a lot better so I will take measurements before and after.

What amperage rate would you suggest to charge these batteries?
I was under the impression to keep these charging at around 1C rate.
I'll even try to get a little video together of the measurements. Not set up for headcam yet.

Thanks for the input and info Jackson.

 

[Michael Fenimore]

Update:
I ventured out this morning into a light haze and winds about 5-7mph with gusts to around 15mph.
Wow, what a learning experience!
But loads of fun!

Here's what I got:
Pre-flight voltage: 4.19V
Post LVC voltage: 3.37V (after shut down and cooling period)
Flight time: Approx. 9:45 (2 slight mishaps; Landed on neighbor's roof after a "short" fly away due to a gust of wind and the usual kiss the ground) Total time on the timer was 10:34.)

Decent flight time with the stock battery I think. This was after charging the battery on the iMax B6 @ 2C rate (1000 milliamps for 1 hour, auto shutoff)

I'm charging up the battery again now with same settings and will take her out once more after the charging cycle.
Keep ya posted.

- Mike

 

[Michael Fenimore]

Last update for today.
Charging:
Charge time - 35:55
Charge rate - 1.0A
End voltage - 4.2V
Current (milliamps) - 492ma (per the iMax display)

Flight:
Pre-flight voltage - 4.18V
Post LVC - 3.43V
Flight time - 8:46

So the way I'm seeing this, charging the battery using the iMax is the route to go.
Less charge time, better flight time and I think I notice better response and power.
The wind is still pretty strong, 8-10mph with 15-20mph gusts.
I basically just kept this in the air fighting the wind the entire flight.

Any input and opinion/suggestions are greatly appreciated.

Thanks.

- Mike

 

[Jackson]

Charging those cheap LiPos at a full amp seems rather extreme to me. But whatever works for you I guess.

Good luck.

 

[Michael Fenimore]

Charging those cheap LiPos at a full amp seems rather extreme to me. But whatever works for you I guess.

Good luck.

What charging rates would you, yourself, use?
I'm up for experimenting and would really like to find a "common" practice with this little lipos.

 

[Newbie Flyer]

Also really interested in the best way to change/store/best practice..... for 1s lipos as I have the Syma x5SC

 

[Michael Fenimore]

Also really interested in the best way to change/store/best practice..... for 1s lipos as I have the Syma x5SC

I've been using the iMax B6 LiPo Balance charger and haven't had any complaints.
I'm averaging 8-10 minutes on the 500mah stock battery since using it. (No camera and no prop guards)
I got my four 600mah batteries today. First thing I did was charge them with the iMax charger.
It's well worth getting the iMax I think. More than likely if you're like me, you'll be using quads with much larger batteries in the future.
Do a YouTube search for it. Too many channels and videos to list.

 

[Newbie Flyer]

Do you charge the batteries individually Michael or simultaneously?

 

[Michael Fenimore]

For the time being I am charging them one at a time. Until I get a "multi-harness" built or purchased, that's the way I have to do it.
But the charge times are reduced considerably. Where the stock USB charger took up to 90 minutes or more, I average between 55 and 65 minutes with the iMax.

I got my 600mAh batteries yesterday and charged them all. Today I took out the X5C-1 and it had an 11 minute flight time.
I'm impressed. I didn't have the time to use any of the others yet, so I am only going on the charge and use of this one.

I have to come up with a spreadsheet so I can track their use and effectiveness over time. Kinda got a "flight log" going with all that data already.