Lynxmotion Tech Support

As I have mentioned several times before, I am reluctant to use standard lipo batteries due to safety concerns, but I like what I have read about lifepo4 batteries as they do not have the fire or explosion issues of liposuction, plus they can be recharged many more times...but I have a few questions.

Any one know a good source for them?

Is it safe to run hs645mg servos on 6.6v bateries or need to go through BEc? If so should you go to a 9.9v?

Lipo charger ok to charge or need other charger?

Kurt

Usually the only things affecting lipos safety would be severe over charging or a nasty puncture to the cell. Most chargers are good about not over charging and there are also battery with hardcases for pretection.

Either way. Check out www.hobbyking.com it looks like they have a decent selection of LiFePo4 batteries for decent prices. I'm pretty sure they ship internationally, too.

Kurt,

Take a look there
http://www.hobbyking.com/hobbyking/stor ... FePo4.html

I only use LiPo all the time for my Copter project.
Never got any problem but i take care of my battery.

_________________
Eric Nantel
Qc Canada

Always liked Robot... Now i am learning to make some...! Wonderfull...

Thanks,
Looks like I could order one from there. Also looks like the lipo charger I have (imax b6) can handle life... The last main question is can the 6v servos handle 6.6v battery? Suppose I could try it and see wha happens.

Kurt

Very interested in these Lifepo4 batteries. I'll certainly be looking into ordering some.

I have an 11.1v Lipo battery that has been totally abused when it comes to charging/discharging.
It has a 3 hour charge time and sometimes I've only charged it for an hour and used it. And sometimes it sits for months charged up or uncharged. Even a year at one point. Plus it's life is only dated to 2011. (Do battery really have a used by date) :/
I completely understand the explosive nature of lipos, and I have my reservations regarding their safely, but I'm wondering if there are any signs to look for 'so one knows when they have had enough.?
Be a shame to throw away a battery that performs well, just because it "might" be dangerous.

Again I understand the dangers so safely is paramount.

_________________
Jonny Poole,
Freelance Concept Art & Animatronics, 3D Art and 3D Modelling, as well as Physical Modelling, Mechanical design, and illustration.
http://www.innerbreed.co.uk
Create, Innovate, Inspire.

A sign that it may be going bad is if it starts puffing up. Then you'll probably want to dispose of it.

FYI - after interacting some with Nathan (AcidTech), I am feeling that it should work and I am going to try out a couple of these.

2x #Z36002S-30/20641 ZIPPY Flightmax 3600mAh 2S2P 30C LiFePo4 Pack (USA Warehouse) = $33.74

My main concern was/is how will the 645mg servos handle the standard voltage of about 6.6v especially when the battery pack is fully charged.

But my understanding now is that these should have about the same voltage as an nimh package. That is I belive that a fully charged LifePo4 cell is 3.6v so a 2S would have a top charge of 7.2v. Where a 5 cell NIMH battery, a fully charged cell is between 1.4 and 1.45v. If we assume 1.45, a 6v battery is 7.25v.

So again I thinking these should work, but I am keeping my fingers crossed.

Kurt

Curious what results you get.

_________________
Coleman Benson
Lynxmotion
Imagine it. Build it. Control it.™
http://www.Lynxmotion.com

They arrived, but I should have ordered some connectors/adapters... They come with 5.5mm Bullet-Connectors. I could hack it off and put another one on, like a Tamiya, off of one of my other battery packs... Or could buy adapters/connectors and make a conversion cable... May try that with at least one of them and see how well it does.

Kurt

I am finally in the process of using one of these. I am converting my T-Hex to run using a Raspberry Pi and thought I would configure over to using one of these.

I now have it all wired up, but still cleanup needed like, finding short USB cables or potentially cutting them down myself... 6'-10' cables to connect something a few inches apart is not the best

One thing I am still trying to figure out, is best way to charge these.

These are the Zippy 3600 30c series, The website says the max charge rate is 2c. I have an IMax B6 charger, which I believe can properly charge this battery, but still trying to figure out how to properly set it for the Balance charge for both the Charge rate and how to set the proper shutoff voltages.

Edit: I think I found the right way to set the battery type. Need to get to User->Program, then it shows Lipo/Life/.. Hit enter, shows Lipo, Hit dec or inc till shows life...

Kurt