LiFePo battery?

[EarthX Lithium]

Originally Posted by tomhanaway

Kathy,
I discussed the following with your associate at Oshkosh. He was going to check.

I understand that your batteries can operate at a higher temperature ( I believe it was up to 60C or 140F) than the odyssey pc-680.

My question was what temperature can they stand with no damage when the plane is sitting still? I.E., after shut down.

Without measuring, I suspect under cowl temps can easily rise to 170-180F. Will the LiPo battery suffer any damage at these temps (assuming shutdown, no load on battery)?

Thanks,
Tom H.

Hi Tom,

We have not forgot about you and this question and will let you know as soon as we have an answer. Sorry for the delay but engineer's do not take these important questions lightly and want to have a correct answer for you. Please be patient.

Kathy

[grayforge]

Tonight, I did some experimenting with voltages and what falls off when...

Everything's running at 12V+, of course.
At 10 volts, the Mini-B drops into Low Voltage Error Mode
At 8 volts, the G3X Touch AHRS drops off
At 7 volts, the G3X Touch display starts failing

Here's a sequence of images demonstrating this.

Everything Running:


Mini B dropped offline:


G3X AHRS about to fail:


Lowest voltage where the G3X display works:

[EarthX Lithium]

"I was able to get the battery installed in my RV10 today. There was only a little bit of work to do to get it to fit. Here are the notes and links to pictures."
http://tinyurl.com/nadnssd



1) The width of the ETX48E is an exact fit for the width of the Odyssey
PC925 - so anyone that is using that battery (most all RV10s), the existing angle piece in the battery tray works perfect to hold the aft end of the ETX48E.
2) The depth of the ETX48E is about 1-5/8" thinner than the PC925 (typically installed on its side). I used a piece of UMHD with some lightening holes to reduce weight to take up the extra room in the tray behind the ETX48E battery.
3) The stock battery tie-down lands on top of the battery but is off the back of the center built up area (where the EarthX label on top is). To fix this, I made a 6"x3/8" piece of UMHD and epoxied it to the top of the battery. The tie-down bar then fell equally on the UMHD block and the exposed battery top.
4) The existing wiring runs from the Master Relay and the Ground Wire were all a perfect length to reach the ETX48E when using the Terminal Adapters to move the attach points to the front of the battery from the top.
5) The screws to attach the Terminal Adapters were outfitted with a lock washer and a flat washer to secure the screws in place. The same thing was done to secure the battery cable lugs to the terminal adapters.
6) A MS25171-3S insulting rubber boot was installed over the top of the POSITIVE side of the battery terminal adapter to protect the exposed terminal. It also protects it from the nearby battery tie-down bar.
7) The change out took about 2 hours including fabricating the new spacers.
8) The battery worked great and it seems like the starter has a little more oomph than the Odyssey battery.


Thank you all who take the time to help out fellow builders and share with us your experiences!

Kathy

[EarthX Lithium]

We met a metal fabricator at the OSHKOSH show and he presented us with this adjustable battery tray idea made out of aluminum and weighs less than 2 pounds. This is a prototype but we thought we would ask all of you for your thoughts or opinions.

[IMG][/IMG]

[grayforge]

That looks pretty cool Kathy.

Thoughts:

1. "Under 2lbs" sounds a bit heavy. I would hope for under a pound.
2. The straps don't give me as good a feeling of security as bolts/tie-down
3. Aluminum will be more likely to stress crack than steel.

But it does hold promise. :-)

[EarthX Lithium]

Thanks for the quick response! Another response received is that Nylon is not very flame resistant and in the event of a fire, having a strap that would not melt off and set the battery "free" is a better idea. Or even better yet, an aluminum case that encloses the battery all together in the event of a fire so it is protected from flames is the best solution. I agree! The width is always the same, the height and length can differ depending on which model is used.

Kathy

[KRviator]

That looks good.

I personally wouldn't have a problem with the nylon straps, particularly for a lightweight lithium battery. I've got a pair of nylon straps that hold the battery in place in my 4WD and it doesn't move an inch and the battery is a heck of a lot bigger & heavier than the Shorai I've got in the -9.

[EarthX Lithium]

Thank you so much for your input and I am sharing everyone's ideas with the metal fabricator as the ideas have been great!

Kathy

[scard]

Again, that has no place on the firewall of an airplane. Surely for comedic relief only.

[David Paule]

Personally, I'd prefer a full enclosure of stainless steel, with a vent opening that can be ducted outside the aircraft. The material can be the same as the firewall.

I have no idea how to design the various openings for cables or access, though.

Dave