What Battery Do You Use?

[colekingx]

I'm in the process of selecting a battery (likely an AGM). In reviewing the batteries mentioned in this forum, I'm am surprised at no mention of using a Yuasa as these seem to be almost the default battery on motorcycles.
Is anyone using Yuasa or have rationale for not using one?

[Shadowrider]

Earthx. kitfox sells them and the battery tray for them.

[jrevens]

I use a Deka ETX-14 AGM battery. It was the original one offered with my kit by Kitfox. For me it doesn’t make much sense to use a light Lithium battery. I could buy 4 of the Deka batteries for the cost of the Earth-X. I have a relatively low total electrical load, and my airplane is already fairly light. A little extra weight firewall forward is actually desirable for my CG. That’s just my airplane. I built my own battery box.

[Andy Battman]

I see from the Kitfox parts catalog, the earthx is going for $379. I would think Kitfox owners would get a discount. .. no ?
So, $379 + $60 for the bracket = $439 total... What justifies this kind of price ? compared to the other lithium aircraft battery available ?

[Dave S]

Odyssey PC 680 AGM over here. Even with the poundage of the old odyssey, we load the plane with myself, my wife, full fuel and 140# of camping gear/baggage within W/B. The AGM batteries aren't fancy or hi-tech or anything, but seem to be long lived, quite durable and get along with little attention and survive period of disuse with little/no loss of charge. Don't know anything about other AGM brands. Also, others experience and mileage may vary.

[avidflyer]

On the cheaper side, I run a 300 CCA lawn tractor battery. It spins the 912 over in my Kitfox 4 just fine. Same one in the Avid Flyer and Jabiru engine. Cost is about $30. JImChuk

[109JB]

https://www.amazon.com/gp/product/B091P96DDB/ref=ppx_yo_dt_b_search_asin_title?ie=UTF8&psc=1

Cranks incredibly fast on my 582. The 582 needs pretty good cranking speed to start in cold weather. This beat an AGM by a long shot. No problems.

[Andy Battman]

Does noco have any customer service if any issues arise ? amazon shows $161.96.. wow, that's cheap ! 7Ah capacity is all thats needed apparently. 600A starting current, wow again..
I wonder how much starting current is actually needed to start my 912 ? I dont read anything about any balancing capabilities in the BMS. For something so fantastic, and so cheap, why are there ANY bad reviews? , I tend to believe them more so...

[109JB]

Does noco have any customer service if any issues arise ? amazon shows $161.96.. wow, that's cheap ! 7Ah capacity is all thats needed apparently. 600A starting current, wow again..
I wonder how much starting current is actually needed to start my 912 ? I dont read anything about any balancing capabilities in the BMS. For something so fantastic, and so cheap, why are there ANY bad reviews? , I tend to believe them more so...

Don't know about service because I haven't had a problem.

[jiott]

I use EarthX for these reasons in spite of its high cost:

Fully built-in, proven cell balancing and safety circuitry.
Now certified for use in certified aircraft.
Lithium-Iron technology-safer than Lithium-Poly.
10# weight savings compared to AGM.
Great cranking power.
No need for trickle charger.
Panel mounted fault light.

I don't think you can get all these features in the cheaper RV/motorcycle batteries.

[Andy Battman]

agreed, I'll be using Aerolithium for the same reasons except for the ' certified ' part which I dont care about and they are a little less costly.

[Delta Whisky]

PC-680. Long shelf life and if needed, almost any battery charger will work. Readily available.

[Eric Page]

7Ah capacity is all thats needed apparently.
As Jim suggested above, there’s more to choosing a battery than its cranking ability and price tag. Consider a few questions:


Are you using an engine with one alternator, or two?
Is your engine self-sustaining, or does it require electricity to run?
How do you plan to use the airplane (VFR or IFR, back-country, cross country or local)?
What is your ship’s running airframe electrical load?
What are you willing to turn off to shed electrical load if all power generators fail?
How much battery-only endurance do you want to achieve?
How hyper-focused are you on minimizing empty weight?

Your battery capacity and chemistry preferences will be different depending on how you answer those questions.

For a Rotax engine, check the electrical section (chapter 24) of the engine installation manual (https://www.rotax-owner.com/en/support-topmenu/engine-manuals). For all of the 900-series engines Rotax recommends a battery with at least 16Ah capacity and 350CCA, but the capacity will obviously be more critical for an electrically dependent engine like the 912iS or 915iS, for which a dead battery = no thrust. The same consideration would apply to any automotive conversion with high pressure fuel pumps, electronic ignition and an ECU.

As an example, I’m using a 912iS in a plane that will be used for day/night VFR and some back-country flying. I plan to use an EarthX ETX-900 (15.6Ah, 400CCA). My plane will be configured to aggressively load shed if I lose both alternators and have to run the engine on battery only. The entire Dynon suite, transponder, ADS-B and most lights will be shut off. I’ll finish the flight using a standby instrument (combined altimeter, airspeed and VSI), comm radio, landing and cabin lights (only as needed) and pitch trim. All of that adds up to a few hundred miiliamps of average load. Finally, I’ll test the battery at least annually to verify its capacity.

[109JB]

I respect everyone's own decision but want to put in my reasoning for going with a powersport lithium battery rather than EarthX. Obviously the big one is cost. I spent $160 from Amazon for the NOCO battery I chose versus $380 for the EarthX. The EarthX is certainly a proven option, but having used lithium powersport batteries in motorcycles for a few years I had some experience with them. Eric brough up some points about the EarthX that I compared to what you get with a powersport lithium battery below. Everyone has to weigh the pros and cons of every selection on building an airplane. For me the cost, the fact that the Kitfox is a VFR airplane, and my previous experience led me to save the $200+ and I don't regret it. For others the differences may be such that you feel more comfortable with the EarthX and that is fine. Just giving my view.




Fully built-in, proven cell balancing and safety circuitry.(All lithium batteries require some kind of BMS. At least the NOCO I have and the antigravity do have BMS with over-discharge, over-charge, thermal protection and cell balancing.)
Now certified for use in certified aircraft.(EarthX has the corner on this but homebuilts don't need certified products.)
Lithium-Iron technology-safer than Lithium-Poly. (Virtually all powersport batteries are Lithium iron phosphate, not Lithium polymer so I don't see how this is a factor)
10# weight savings compared to AGM.(You get this with powersport lithium batteries too)
Great cranking power. (Same with powersport lithium batteries)
No need for trickle charger. (Haven't needed one on my 582 powered Kitfox with powersport lithium battery either and the 582 has a weak charging system compared to even a 912UL.)
Panel mounted fault light. (The powersport batteries don't have this, but then again a standard battery doesn't either. For a vfr airplane I don't see this as a huge deal.)