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-   -   Picked up an earthX LiFePo4 battery at Oshkosh (http://www.vansairforce.com/community/showthread.php?t=127942)

schristo@mac.com 07-25-2015 08:53 PM

Picked up an earthX LiFePo4 battery at Oshkosh
 
I picked up a LiFePO4 battery at Oshkosh from earthX, model ETX680. I Installed it at the show and now have a bit of time with it for evaluation.

It is amazingly lightweight... 4.12 pounds on my scale! This replaces my 14.4 pound PC680 AGM battery. A real savings of more than 10 pounds. Crazy.

The form factor is very close to the PC680 and the idea is to use the existing battery box. This works with a couple of notes. The earthX battery is about an inch narrower and just a smidgen thicker and when first installed I had to rock it back and forth in the box to get it in and could not get it to seat all the way to the bottom. Initially it looked like it might not ever come out!

After flying nearly nine hours home it worked itself into the box and now slides in and out just fine.

The terminals are center mounted so I had to fabricate new hold downs. I made a couple of tabs out of .063 using the existing nut plates. This worked out great.

The battery from right out of the box had a strong charge and delivered around 12.8 volts to the bus. During my departure the alternator was flowing around 25 amps to charge, that dropped off gradually and after 40 minutes or so it was fully charged. Pulled from the plane with a full charge my meter shows 13.7 volts.

The chemistry for this battery is quite a bit different than a traditinoal lead acid. The battery will not fade voltage as it discharges or comes under heavy load. It will hold and deliver close to the rated voltage until it nears the end of its capacity. Very different... even cranking the starter the voltage on the bus was above 12!

Apparently, any lithium based chemistry is based on 3.3 volts per cell and there are 4 to make up a 12volt pack; actually 13.2. It is critical that these individual cells be managed for charging. EarthX uses redundant built in charge management circuits within the outer case and includes a remote status indicator and contact. The indicator or the case faces the firewall and I have not yet connected the contact to my panel.

There has been quite a bit of discussion about the safety of Lithium batteries in general... the advantage of the iron phosphate derivative is its thermal and chemical stability.

https://en.wikipedia.org/wiki/Lithiu...sphate_battery

Fly Low, Go Fast, Turn Left ;)








blahphish 07-27-2015 02:53 PM

Just wanted to put another data point out there. We have been flying with the EarthX for almost a year now and it is solid. No complaints at all and the weight savings is great especially in the back of the -10 where aft CG issues can be a challenge sometimes.

chazking 07-27-2015 06:34 PM

Batt used
 
Brian,

What size EarthX battery did you use? What Battery did you replace?

Chas

blahphish 07-28-2015 02:43 PM

I went with the ETX36 because at the time the ETX900 didnt exist. If I were to do it again now I would do the 900 since it has redundant electronics and a fault monitor and a little more power too. I previously had the Odysey 925.

To make the battery fit I cut the two bolts that hold the battery down and re-tapped them and then I drilled a couple holes in the bottom of the battery box and pop riveted on a piece of angled aluminum right up against the new battery to make it fit nice and snug. I think you could make any battery fit pretty well and pretty easily this way in my opinion.

RAFRich 07-29-2015 11:27 AM

Quick question for everyone here.

I was also at the show and saw a few lithium companies, but I wanted to find out some things about them first.

Biggest question for me is where the battery is built. I have purchased lithium batteries in the past, and for the most part they've been built in China or Korea - and those didn't do well. I've come across some companies that put "Made in the USA" but it was really made in China despite that claim, they only put stickers on it or some other nonsense.

I can't find a definite street address, just a PO Box from them, and the only address I did find was for someone's house.

Can anyone help me to verify these guys so I can feel confident about them over other companies? I'm looking around, would like to feel safe about losing that weight.

Thanks!

Mike S 07-29-2015 11:32 AM

Welcome to VAF!
 
Rich, welcome aboard the good ship VAF:D

RAFRich 07-29-2015 12:38 PM

Thanks, Mike!

Lan Vinh Do 07-29-2015 07:01 PM

[quote=blahphish;1001253]I went with the ETX36 because at the time the ETX900 didnt exist. If I were to do it again now I would do the 900 since it has redundant electronics and a fault monitor and a little more power too. I previously had the Odysey 925.


Hi Brian. I will probably go with the 900. Just want to know, Does it swing the prop of the io-540 well or you feel it's underpowered?

Aggie78 07-29-2015 07:33 PM

Thanks for the review.

I swung by Earth-X a few times at the show as well, but just couldn't put a bullet in my old 680 yet as it still swings the prop with gusto. I hate putting something that still works well out to pasture, but when it gives me the slightest inkling of starting to croak, Earth-X's product will be at the top of my list...

Now, if only it was as easy for me to lose 10 ugly pounds with one swipe of the credit card as it is for the RV!

Please keep us updated on your experiences...pro and especially, con.

Thanks,

Rob

RV8iator 07-29-2015 08:31 PM

A year later
 
AirVenture 2014 i bought two earthX 36d's and installed them in my 8. A year later I am completely satisfied.

I replaced a PC680 and a smaller 9 amphour standby battery. I had a contactor fail one time and the brain in the earthX shut it off as advertised. Went through the reset procedure and in a couple hours back to good as new.

I installed a temp monitor between the batteries for added peace of mind.

The cranking power is notably better than the 680. I think I could taxi on just the starter...

Just another data point.


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