LiPo in the Tx

Dumb Thumbs · Posted: Sat Oct 23, 2010 7:26 am Post subject: LiPo in the Tx

Word to the wise for anyone using a LiPo to power your Tx; Pull the battery to check the voltage, don't go by the Tx battery gauge to wait to charge. My Dx7 with a fully charged LiPo of only a few hours read FULL charge. I checked the battery with a tester and it was like over 75% drained. It's just how LiPo's discharge vs Ni-MH bats discharge I guess.

Crashagain · Posted: Sat Oct 23, 2010 10:54 am Post subject:

My Futaba displays the voltage. If you have a graph type bar then you won't get an accurate reading.
Also do not let the voltage go below 11.1V Lipo's don't discharge at a slow rate like nicad's, a lipo will reach a certain point then drop off, fast enough that you won't get a warning beep from you radio telling you that your voltage is low.

Dumb Thumbs · Posted: Sun Oct 24, 2010 7:12 am Post subject:

Thanks Crash, The Dx7 displays the volts and a bar graph, but I always just looked at the graph when I had Nm battery in the Tx. Now I'll keep an eye on the volts for sure! I'm hoping after a few cycles the LiPo will hold a charge a bit longer. Only other thing is I'll have to make double sure that the Tx is off before I put it away. Don't want to over drain the LiPo and kill it.

Crashagain · Posted: Sun Oct 24, 2010 1:31 pm Post subject:

I fly every weekend. Sat and Sun, and I charge my lipo once a month.
It's a 2600mah 4C pack. I have been very happy with it. When ti comes time to change it out, I am going with the Hyperion pack. I forget what the battery type is, but it's similar to the A123 Life packs. Instead of starting at 12V it starts at 9.6V and last every bit as long as a lipo, but it does a slower drain so you will get a low battery warning from your radio.
The advantage is, it won't void your warranty by using, you can charge it like a lipo or thru the radio with your stock charger.
Here is the link for it.
http://www.hyperion-world.com/products/product/HP-FG305-2100-3S

Dumb Thumbs · Posted: Sun Oct 31, 2010 11:50 am Post subject:

Well I seem to have something going wrong. I just checked the battery
(an NRG 2500 mAh) after about hour & 1/2 use. Good thing I did check when I did, it was 50% dead. It's charging now and has taken 990 mA already and has a way to go. I don't understand why this LiPo drains so fast as opposed to the Ni-MH bats that would last a month or more.
OK just finished charging just now and took back 1014mA total. That's a lot for 1 & 1/2 hours in a Tx I'd think, or am I wrong?

Crashagain · Posted: Sun Oct 31, 2010 1:15 pm Post subject:

That does not sound right to me.
The most I put back is around 860mah.

Crashagain · Posted: Mon Nov 08, 2010 9:32 am Post subject:

Update..
This week I got my new battery for my TX. I bought the Hyperion pack that you can see in my previous post.
This thing rocks. They come pretty much fully charged, it only held 180mah to top it off. I left the radio on for a few minutes and then plugged in my wall charger to test it out. It took about 10 minutes to top off the pack again and then it shutt off like it does with the stock nicad pack. Way cool...
I went flying yesterday, and I flew over a gallon thru my bird and the battery is still sitting at 9.9V
It never moved. My buddy said that he left his radio on and it took over 12 hours before it shut off. thats alot of flying time if you are only in the air for 5 to 10 minutes at a time.

Dumb Thumbs · Posted: Tue Nov 09, 2010 4:25 am Post subject:

Thanks for the info Crash, I'm gonna have to get one. Wish I knew about these batts before I got a LiPo for my Tx.

solentlife · Posted: Fri Dec 31, 2010 9:49 pm Post subject:

I use standard over counter NiMH AA's .... rated at 2600mAH

I get near 13hrs out of my FlySky 9X and over 15hrs out of my 6ch Heli Tx.

All charged via normal radio socket and charger.

Dumb Thumbs · Posted: Mon Feb 07, 2011 8:47 am Post subject:

So I just got myself a Hyperion LiFe pack for my DX7, but I have a question. After charging in the Tx over night (I don't have a Hyperion balance board for my Bantam chargers) the Tx display reads 10.1 Volts but the bar graph shows less then 1/2 charge left. Is that normal?

Crashagain · Posted: Mon Feb 07, 2011 12:40 pm Post subject:

I would trust the numbers and not the graph. It will start out an 10.1V for a few minutes and then it will drop down to 9.9 and stay there for a long time.
I just charged mine last night for the first time in 5 weeks. It held 1200mah. That is less then half, pretty good considering how much I fly.

Dumb Thumbs · Posted: Tue Feb 08, 2011 8:03 am Post subject:

Thanks for clearing that up, thought I might have gotten a bum batt. I guess different type batteries not are rated the same way. I just checked a Spektrum Ni-MH 9.6V Tx pack that was 3/4 drained according to the bar graph in the Tx. It reads 9.9V on a 9.6V batt Rolling Eyes

. When I put in the LiFe 9.9V pack it reads 10.1V. So I assume that NiMH batts are rated at a nominal charge value vs LiFe rated at max Volts. Good to know, thanks again!