Yup tks! I actually did the Google search already and it seems the consensus is that you can charge a LiFe with the Lipo setting, but you just need to be very careful about manually ending the charge at 3.3V (rather than the default Lipo setting of 4.2V). I just wanted to confirm that this is true

Also since both HS82MG and HS85MG servos are rated for 6V, I assume they won't burn up with the 6.6V LiFe pack?

Best,
Kevin

Well, I had a beautiful maiden flight and it flew like a dream.

Until the end...

E-Flite Habu 32 Crash - Maiden Flight Meets Light Pole (0 min 48 sec)

Oh man... It hit that post hard on the wing I guess, sucks! Sorry

Yeah, frustrating that it was so close to missing all together. Probably only nicked 1cm or so on the tip of the wing. I should have flown higher on the go around I guess. Oh well. I'll rebuild it and try again next week

Originally Posted by kchen95

Yup tks! I actually did the Google search already and it seems the consensus is that you can charge a LiFe with the Lipo setting, but you just need to be very careful about manually ending the charge at 3.3V (rather than the default Lipo setting of 4.2V). I just wanted to confirm that this is true

Also since both HS82MG and HS85MG servos are rated for 6V, I assume they won't burn up with the 6.6V LiFe pack?

Best,
Kevin

Actually, 3.3V is the nominal voltage and I believe LiFe/A123 packs normally terminate at 3.6V/cell. Almost all chargers have a LiFe setting, do your self a favor and take the time to figure out how to get your charger configured correctly for Life/A123..

As for your servos, look up the ratings, if they say 4.8V - 6.0V (4 or 5 cell) operation they should be fine with an 2S LiFe pack which has the same voltage characteristics as a 5 cell NiMH pack..

Originally Posted by kchen95

Yup tks! I actually did the Google search already and it seems the consensus is that you can charge a LiFe with the Lipo setting, but you just need to be very careful about manually ending the charge at 3.3V (rather than the default Lipo setting of 4.2V). I just wanted to confirm that this is true

Also since both HS82MG and HS85MG servos are rated for 6V, I assume they won't burn up with the 6.6V LiFe pack?

Best,
Kevin

You can use one of these on your LiPo charger to charge LiFe packs. I had one for awhile before I bought my FMA charger. They basically cutoff at the proper voltage just as you are thinking. Problem is, at $40, it's almost better to get a charger if you are planning on using LiFe cells going forward. Hot off a charger, a LiFe pack is charged to 3.65 volts/cell but they drop fairly quickly to 3.45 volts/cell. Problem is, they stay at that level or very close to it until falling off a table. So your servos see fairly high voltage for the entire discharge cycle. I've used 6V rated servos with LiFe packs but it is a little hard on them.

I use a life on all my jets, my receiver puts out 6 volts , regardless of weather it's fully charged or not, fully charged is 7.2 volts. I have telemetry Hooked up and you can see volts on receiver . HK has some really nice nanos 20-40c http://www.hobbyking.com/hobbyking/s...dProduct=28656, I've found that almost all chargers will charge life batteries, the cheap one from eBay works great $20.

New Habu up and running with tamjets struts and servo controlled front gear door

Originally Posted by Sit-N-Fly

You can use one of these on your LiPo charger to charge LiFe packs. I had one for awhile before I bought my FMA charger. They basically cutoff at the proper voltage just as you are thinking. Problem is, at $40, it's almost better to get a charger if you are planning on using LiFe cells going forward. Hot off a charger, a LiFe pack is charged to 3.65 volts/cell but they drop fairly quickly to 3.45 volts/cell. Problem is, they stay at that level or very close to it until falling off a table. So your servos see fairly high voltage for the entire discharge cycle. I've used 6V rated servos with LiFe packs but it is a little hard on them.

OK looks like I figured it out - my charger does have a specific LiFe setting I feel like I've read this somewhere before, but to make it perfectly safe on the servos that are rated for 6V, can I just not charge the LiFe fully to 3.6/3.65 and instead stop it at 3.0-3.3V? Or does this not make any difference?

Kevin

No difference , I've been flying Habu 32 for a year and F4 for 6 months on life and stock servos , not one problem.

Originally Posted by mulicheng

Well, I had a beautiful maiden flight and it flew like a dream
Until the end...

Ouch! Sorry to hear about your Habu. I agree, they fly like a dream! Your next one will be even better.

Originally Posted by kchen95

OK looks like I figured it out - my charger does have a specific LiFe setting I feel like I've read this somewhere before, but to make it perfectly safe on the servos that are rated for 6V, can I just not charge the LiFe fully to 3.6/3.65 and instead stop it at 3.0-3.3V? Or does this not make any difference?

Kevin

LiFe's are tricky to charge. I think you will find you only have 20-30% of the full capacity if you only charge to 3.0 v. Most of the capacity of the pack will be delivered on discharge before you notice much drop in voltage at all. My LiFe's charge to 3.6 V. As soon as you take them off the charger they drop to 3.3V. I haven't had any equipment fail on 6.6v. (Doesn't mean you couldn't, but I haven't seen it) If you are afraid to deliver 6.6v to your stuff I would find some other solution.

Originally Posted by jwjohnson

LiFe's are tricky to charge. I think you will find you only have 20-30% of the full capacity if you only charge to 3.0 v. Most of the capacity of the pack will be delivered on discharge before you notice much drop in voltage at all. My LiFe's charge to 3.6 V. As soon as you take them off the charger they drop to 3.3V. I haven't had any equipment fail on 6.6v. (Doesn't mean you couldn't, but I haven't seen it) If you are afraid to deliver 6.6v to your stuff I would find some other solution.

Tks again for all the valuable advice from everyone! When storing a LiFe, should I maintain a particular voltage level? I know Lipo's should be stored around 3.8V; is there an equivalent for LiFe?

Kevin

I know this is product specific but go here (http://www.lifesourcebatteries.com/receiver-packs.html) and pull up one of the manuals. It should help you with the care and use of LiFe batteries. I have used a LiFeSource battery to power a 50 size heli for a couple of years now. Only problem I had is it fried a Futaba servo that was rated at 4.8v. All my other servos that are rated at 6.0v are not having any problems. Just food for thought. Todd

It's worth checking your voltage out of your Rx. I put 6.6 nominal in and the RX steps it down by about 1to 1.2 volts. That puts most servos in the range.

Originally Posted by Tealc

I know this is product specific but go here (http://www.lifesourcebatteries.com/receiver-packs.html) and pull up one of the manuals. It should help you with the care and use of LiFe batteries. I have used a LiFeSource battery to power a 50 size heli for a couple of years now. Only problem I had is it fried a Futaba servo that was rated at 4.8v. All my other servos that are rated at 6.0v are not having any problems. Just food for thought. Todd

Tks so much; this was exactly what I needed!

Kevin