need bigger battery for futaba 9ch

[markg]

i have a 9chp and need a battery with more run time.

have found a ni metal hydride one at 2700 mah, and a 3s li pol at about 2500 mah, so they are about the same capacity vs. the oem 700mah.

any pros/cons about using either? i assume the niMhy can be charged via the standard charger, though it might take a couple days, while the li pol may need to be removed and charged each time. but not sure.

recommendations?

mark

[Pinecone]

Lipo shuld be removed to charge, or you could lose your radio.

Lipo will be lighter. But they do deliver a bit more voltage when fully charged.

[BarracudaHockey]

Get a NiMH and treat yourself to a decent charger, I use an accucycle elite, I have 1650 pack in my 9c and can fly all weekend.

[markg]

lighter is nice; and i already have a thunderpower 1010c charger that will do lithiums, but nothing for nimh (assuming i need an external charger for that), so lithium it is!

thanks for the inputs

mark

[PaulH]

The owner of Hangtimes Hobbies used to work for SR Batteries. The packs he builds are comparable to those available from SR Batteries, but at half the price. Check out his transmitter packs: http://www.hangtimes.com/txpacks.html

The 2700 mAh NiMH battery pack is an excellent choice. I have been using a home-made 2300 mAh pack for two years now. I can't tell you how many hours I get out of it because I have never run it down while at the field! I can tell you that I have completely set up a helicopter (90 minutes or more) and then put a few flights on it. My receiver pack usually needs topping off somewhere along the line, but the transmitter is still going strong.

I would recommend buying the wall-wart charger that Hangtimes sells. You will find it on the same page that I linked above. It will trickle charge the transmitter pack at C/20 without removing the pack. Because of the slow rate, it's gentle on the cells. You can leave the transmitter plugged in to the charger all week long and it will be ready to go when you need it. And, if necessary, you can always fast charge it at the field.

The lithium transmitter packs are nice, but in my opinion the NiMH pack balances the transmitter better. I use a neck strap, if it makes a difference. Also, if you do not already have a lithium charger, you would have to buy one that is 3S capable.

[jgunpilot]

I've got a 1650 pack, but it doesn't seem to last all that long. PaulH, thanks for the tip on where to find a 2700mAh pack.

[GimbalFan]

The packs he builds are comparable to those available from SR Batteries, but at half the price.

Second that. Good packs.

[PaulH]

I see at least eight battery packs in my future. I intend to get all of them from Hantimes Hobbies. My winter project is a SIG Four-Star 120 (just picked it up!) that will receive an EI gas engine. That will need three packs (two for receiver, one for ignition). My second Intrepid Gasser will need two for receiver. My original Intrepid is going to get two new receiver packs. On top of that, I'd like to get one of his transmitter packs.

The reason I say two receiver packs is that I like using a fully redundant setup. A pair of 1800-2000 mAh packs together running through two separate switches and into the receiver doesn't weigh that much more than a single high-capacity (3700+ mAh) sub-C pack. The best case scenario is that I double my flight time and halve my pack's internal impedance. The worst case is that something fails and I find it between flights, but it won't cause a crash.