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Earthx lifepo etx680c mounted on firewall

gggflyer

Active Member
Just purchased an RV4 with an odyssey 625 mounted on the firewall. It has a high compression IO320 installed and this battery just doesnt have enough cranking power.

I would like to replace it with Earthx lifepo etx680c. My concern is temperature. It is rated for 60 degrees C but i think it might get hotter than that on the firewall. I live in phoenix so will be flying in 110 degree days so engine area seems to get toasty.

Anyone have one mounted on firewall? Any issues with it.

Thanks

G
 
Measure the temps, and if it's within spec get the EarthX. It tends to get hot on runup and a few minutes after shutdown as the cowling gets heatsoaked. Otherwise a new Odyssey should do the job. You can crank a 540 with a PC680 battery and it's not much bigger than the 625.
Permanent magnet starters need more juice to get going and crank much slower. Getting a Skytec 149-NL (or 122-NL depending on your ring gear setup) starter helps a lot too.

Lenny

i think it might get hotter than that on the firewall.
 
EarthX also sells the high polish insulated battery box to help with the firewall heating issues.

…get that polished insulated box with the bracket for clamping-in-place a blast tube from the engine baffle back wall to the battery. I’ve had zero trouble with battery temps.
 
Temps

I had issues with temperatures on my RV-7 until I added the 1” blast tube and put heat reflective material on the battery box. No issues since then. I also used the Dynon carb temperature probe to monitor the battery box temps.
 
EarthX won’t fit in the 680 Vans box….

You can make the earthx fit in the Vans 680 box with spacers, but it’s not pretty. The box from earthx is nice, except the nut plate edge distance of the design is close and the stainless (at least of mine) was tougher than expected to drill. The earthx does spin the prop with (Cartman inspired) authority.
 
…get that polished insulated box with the bracket for clamping-in-place a blast tube from the engine baffle back wall to the battery. I’ve had zero trouble with battery temps.
Scroll, how big a blast tube? Do you aim it at the top of the battery? Also has anyone tried putting a steel shield on the nearest exhaust stack to cut down on radiant heating of the battery?
 
Earth x does not fit battery box

One would think EarthX would wise up and produce a battery the same size as a PC680, incl current input limiter (say 20 or 30 Amps) to work with our alternators. The extra electronics would be trivial in cost compared to the battery cost. The larger box cost would also be trivial.


You can make the earthx fit in the Vans 680 box with spacers, but it’s not pretty. The box from earthx is nice, except the nut plate edge distance of the design is close and the stainless (at least of mine) was tougher than expected to drill. The earthx does spin the prop with (Cartman inspired) authority.
 
Battery

I have Odyssey 680 on firewall, 0 320 with 10-1 pistons. It cranks just fine. I have a ground from main airframe ground to starter. Non RV.
 
Scroll, how big a blast tube? Do you aim it at the top of the battery? Also has anyone tried putting a steel shield on the nearest exhaust stack to cut down on radiant heating of the battery?

It’s a 1” black plastic tube like Scott mentioned, aimed at the top of the battery.
 
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