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The EarthX experimental aviation batteries are so much more expensive than powersports batteries because they have a dual-redundant battery management system that protects against over-voltage/over charge, over-discharge protection (leave the master on accidentally and totally discharge an unprotected lithium battery and you'll kill it - permanently), over-heating protection (from cranking the engine too long), fault-light indicator, and automatically balance-charges the cells for optimum life and performance. I initially did use a "Ballistic" brand powersports battery with my Jab 3300 and it worked great, but periodically, the cells had to be manually balance-charged for optimum performance and cell life. (Luckily I already had a cell balance charger!) The Jab uses a Kubota regulator and the Ballistic had no problems with it. However, the balance-charging was too much of a hassle for me and I put the Ballistic battery in my infrequently-used motorcycle and went to the EarthX for all the advantages it provides. I've got several hundred hours on the EarthX and it works great and requires zero maintenance.
All that being said, if you go with a powersports battery, be sure it is a LiFePO4 (lithium iron phosphate) chemistry since these batteries will not spontaneously combust as do lithium polymer batteries.
(not affiliated with EarthX, just an obviously satisfied customer!)
Ditto for going EarthX for the all the safety features and smart circuitry. After only three months I inadvertently left the master on while doing maintenance and left the aircraft for a week in the hangar. Fortunately for me the battery was smarter than me and shut itself down at around 11 volts and went to sleep. I bought a LIfepo4 charger and just now put it on the battery and by the morning it will be back to normal.
In the 100 dollar range and usable in cockpit or firewall forward, odyssey pc545 or 680 agm.
I think the 545 is five pounds or so heavier than the earthx
Thanks folks. I now have an Odyssey PC925, which weighs about 24 pounds, starting an O200 in the South East. I should probably opt for the EarthX, but $400 for a battery just plain hurts. No pun intended.
We have two EarthX 680C batteries, a total weight 8 lbs. Since our Viking 130 engine is dependent on electrical power, we decided paying a premium for a light, powerful, and reliable battery is worthwhile investment. Our aircraft is stored outdoors, and last winter we tested the batteries by starting the engine with only one battery at a time; outdoor temperature was around 20ºf. The engine started right up, which speaks well for the engine, as well as battery.
Loren: How did you switch between batteries?
A battery relay is attached to each battery, and each relay has its own toggle switch. Below is our engines wire diagram showing how the batteries are connected. We use locking toggle switches for critical components such as batteries and fuel pumps. More can be seen at www.facebook.com/Experimental750ES
I'll join the bandwagon. EarthX is expensive for a reason - it is worth it. A "normal" lithium battery can be destroyed by mismanagement. Even worse, it has the chance or running away and damaging or destroying your airplane.
If you wanna go lithium go EarthX, in my opinion. Note - like John Austin I have no relationship with EarthX other than satisfied customer, I run one in my 1500 CC motorcycle and it is wonderful! When my Zenith is built it will have EarthX also.
By the way, the higher cost of the EarthX is partially offset by the fact that it should outlast a lead acid battery, lasting two or three times longer (or even more) than a lead acid battery. So your larger upfront cost gets spread out over many more years before replacement time comes along. At least, that is the theory. Time will tell.
If you wanna go cheap, do not go with a lower grade of Lithium, the downsides are too big. Go with a good old fashioned lead acid battery and eat the weight penalty. At least gong cheap will only cost you weight, not other problems.
My two cents for what it is worth...........
Worth a bit more than $0.02..thanks