Nano QX E-Flite 1S batteries storage voltage

[tshoval]

Hi,
Got a Nano QX for b-day (love it).
It came with a 1s 150mAh battery, and a usb charger.
Went through 30-40 charge cycles (charge, fly, let it rest somewhere between an hour and a day, repeat).

Now the battery won't hold more than 2 minuets of flight time (was about 6.5 minutes).

Got new batteries. original ones.

And here's my question.
Lipos should be stored at, well, storage voltage.
The supplied charger can only charge the batteries to their fullest. No storage charge, no discharge, etc.

What is the best course of action (till I get a better charger and a connector matching the batteries)?

A. Store them after charging them
B. Store them after I'm done flying (I fly till LVC cutoff)
C. go through the enormous hassle of charging and measuring the voltage with a multimeter in intervals.

BTW, If any of you know what is the JST part name (and gender) I need to get so I can connect this to a regular charger - please post it.

 

[PhenomPilot]

Storage is 3.85volts. Without a voltmeter, I would charge batteries full and fly two minutes off them so they aren't sitting full or dead. Also, make sure to land before VLC if you can because they usually set it too low which gives you longer flight time at the expense of you buying more of their batteries in the long run. The plug type is called a pico Jst (I think) but I would just search for nano qx batteries on ebay and pick up a parallel charging cable for about $6. Make sure it isn't for nano qx 3d. The plug type for that isn't the same.

 

[tshoval]

Thanks. I'll give it a try.

 

[razor02097]

Hi,
Got a Nano QX for b-day (love it).
It came with a 1s 150mAh battery, and a usb charger.
Went through 30-40 charge cycles (charge, fly, let it rest somewhere between an hour and a day, repeat).

Now the battery won't hold more than 2 minuets of flight time (was about 6.5 minutes).

Got new batteries. original ones.

And here's my question.
Lipos should be stored at, well, storage voltage.
The supplied charger can only charge the batteries to their fullest. No storage charge, no discharge, etc.

What is the best course of action (till I get a better charger and a connector matching the batteries)?

A. Store them after charging them
B. Store them after I'm done flying (I fly till LVC cutoff)
C. go through the enormous hassle of charging and measuring the voltage with a multimeter in intervals.

BTW, If any of you know what is the JST part name (and gender) I need to get so I can connect this to a regular charger - please post it.

Hi tshoval!

To answer your question about the connector the battery has an E flight male ultra micro plug. So you would need a female E flight ultra micro connector to hook it up to your charger.

The general rule of thumb is to store your lipo batteries at around 3.85V. This seems to be the voltage that the polymers will not break down and is in fact what a manufacturer ships them at. If you are planning on storing your batteries for longer than a week, I would recommend charging them up or discharging them down to the 3.85V. If however you are continually using them I would not bother and just fully charge them every time. The only condition I would not recommend is to leave them at the LVCO voltage. LiPo batteries do not like low voltages. They get mad and puff up. Now the tiny cells probably won't puff up much if at all but the capacity will drop like a rock when internal damage occurs.

 

[tshoval]

More info

Hi,
I've taken all the info provided in the answers to my original post into account.
The course of action I've chosen is:
First, don't fly till LVC. Fly for 5 minutes and land.
Second, get a proper charger and make connectors to charge to storage voltage as I should.

I'm using a Turnigy 9x with the ER9X firmware set to run the timer only when the throttle is above zero. Not very accurate, but assuming I fly indoors and play with the throttle a lot, I think the most 5 minute sessions will use the same amount of mAh.

So I've tested. And here are the results:
Battery 1 - flown to LVC - 3.72v
Battery 2 - flown to LVC - 3.58v
Battery 3 - flown to LVC - 3.65v
Battery 4 - flown 5 min - 3.72v
Battery 1 - flown 5 min - 3.70v

As you can see, flying to LVC (till the Nano QX starts flashing red & blue and lands) does not drain the batteries to an unacceptable low voltage.
Flying to LVC, in my case, means flying for about 6 minutes and 20 seconds (on average).
There is little or no difference between flying to LVC and stopping on the 5 minute mark.

So, what now?
Are you interested in seeing more measurments?
What do you think about charging a battery and then flying till the voltage is down to storage voltage? Is it a good practice (battery life wise. flight length is obviously shorter)?

 

[krinaman]

As you can see, flying to LVC (till the Nano QX starts flashing red & blue and lands) does not drain the batteries to an unacceptable low voltage.

Yep, LVC kicks in before you hurt your batteries. When you get in trouble is when you keep flying after the LVC warning (not even possible on your quad).

If you are flying daily I wouldn't worry about storage charging them either. My guess is you just got a bad battery or the USB charger is overcharging them.

 

[Fyathyrio]

Here's one example of a way to connect your real charger to nQX cells.