SonexBuilders.net

While at OSH, I saw several battery options. I was curious what everyone recommends if you were to be buying new as part of your build.

One in particular stood out, due to its lightweight and size: EarthX LiFePO4 Battery.

Model Price Nominal Volts Ah
(1C rate) Crank Amps (PCA/CCA) Weight Case Size (L x W x H)
ETX12A $169 13.2 4 220/135 1.3 lb (.6Kg) 4.5” x 2.6” x 3.7”
ETX18B $219 13.2 6.2 340/230 2.2 lb (1.0Kg) 5.3” x 2.6” x 4.1”
ETX24C $259 13.2 8 420/270 2.6 lb (1.2Kg) 5.9” x 3.4” x 4.5”
ETX36C* $349 13.2 12.4 680/320 3.9 lb(1.8Kg) 5.9” x 3.4” x 4.5”
ETX680* $379 13.2 12.4 680/320 3.9 lb (1.8Kg) 6.5” x 3.1” x 6.6”


Any thoughts on these or have other recommendations for a light, powerful battery?

Thanks,
Josh

I stopped by the EarthX booth at Oshkosh and the salesperson told me that their batteries had internal circuitry that would prevent the battery from being discharged to the point where it would damage the battery. That's something to consider as LiFePo4 batteries can become paperweights if they are discharged below a certain level.

I purchased a EarthX battery specifically because of the safety device that prevents over discharge. It may have paid off today....I found that I had left the EIS switch on after flying last week and the battery didn't even have enough voltage to turn on the EIS screen. I plugged it into my charger and it seems to be charging OK.

The idea of saving 8 founds by swapping my lead acid battery for LiFePo is attractive. But folks with a light engine (non-turbo Aerovee, Jab 2200) may find that there's little useable improvement in useful load due to CG factors. My plane, with two aboard, is already biased a bit toward tail heavy, and the full 40 lbs can't be put in the baggage area or I'll exceed the aft CG limit. While losing 8 lbs of battery weight improve climb performance a tiny (imperceptible) bit when flying solo, it would decrease the amount of baggage I can carry. I'm sticking with lead acid (AGM) technology for now . . .

I had the same problem (different plane though, RV8A) With the light battery I had an aft CG with a backseat passenger over 160. I moved whatever I could forward. The biggest gain was from moving the ELT forward. Those little suckers are heavy!

All you kids rushing to get the new lithiums from Sonex, care to sell your old school battery to someone who still needs the weight up front? My Odyssey is reaching its life end and will be needing a fresh one.

I have the 680. I have to say it's incredible. I have it mounted on it side so it slides straight out the left side of the plane with the earthx battery case. The safety circuit saved me once already. And it cranks really well. Being a turbo Tri gear it's a nice 11lb knocked off the front.

The company line:
https://www.youtube.com/watch?v=wzuysON9ey8
Certainly sounds attractive, other than the price. Almost 4 times the cost of the Odyssey.

How many CCA is required for an Aerovee? Is the ETX12A enough battery?