Lithium Battery for your Aircraft
Has anyone installed one at annual, or when a new battery was needed in any model Cessna?
I am intersted. I see nearly all benefits with no drawbacks. Lighter weight, hotter spark translating to better start, longer term reliability, extremely low dissipation of the charge when not utilized.
If someone has done so I'd like to hear about it. Thank you.
Comments
Hi stratus11,
No personal installation experience, but a few points about the current crop of Lithium batteries for you to consider...
Most on the market today are for experimental aircraft. Those that are "approved" for normally certificated aircraft seem to have TSO approval for the battery itself, but not for the installation unless there is a specific STC for make and model or through a field approval and form 337 on file with the FAA. Some have found it difficult to navigate this process. Yes, for larger aircraft installations the situation is better, but at a very significant cost.
Price wise, after a quick search, you are looking in the neighborhood of $400 at the low end to over $4000 at the high end; ballpark. In terms of capacity, they raise in price as capacity goes up. The capacity of my Concorde is 35 amp hours. I had a hard time finding an approved battery to match this capacity which is important as this parameter sets the amount of time you have to navigate and get the aircraft on the ground safely in the event of an alternator failure.
Depending on where the battery is mounted, the significant weight difference will most certainly require the weight and balance data for the aircraft to be updated.
No doubt, over the coming years, this situation will improve but not sure I would want to be an early adopter. By the way, although the lithium battery will give you good cranking power, I cannot see how it is going to give you "hotter spark" for better starting. The magneto may be turning faster but the energy in the spark is dependent on other factors, not the least of which is the supply voltage which remains the same.
Regards,
Mike
Thanks Mike. I’ve replaced one Mag with the Surefly electronic ignition. That is providing better ignition spark, based on the specifications of the equipment. I’m sure you’re right on the Mag capabilities. Cranking power is extremely important as you know. I expect better crank power to translate into longer lasting starter equipment.
Like most things in aviation I believe this technology is beyond mature. The 787 had lithium batteries in the late 2000s. Sure it had its issues but that’s another story. I’m all in. I’m looking forward to it. Once I install, I’ll let people know how it goes. If it blows up airborne and I crash, I guess you will all know.
This technology should’ve been certified across the light civilian aircraft spectrum many years ago. I blame the FAA approval process for this very good technology delay.
This enhancement would also save fuel with the weight savings and reduce the number of batteries we burn through. Just my humble opinion.
The EarthX battery is approved for some Cessnas, those where the battery is mounted in the tail cone.
They do not approve mounting the battery in the engine compartment, on the firewall. It cannot tolerate the high temps.
Note that for a C172 the difference in weight is 18 lb, or about 3 gallons of gas.
Also the approved model in only 15 amp-hr vs 24 for a Concorde RG25xc.
So, I see no advantage in using a Li-ion battery...
I have an Earth-X, and I love it. Particularly for the smaller Cessna’s, it’s genius! It’ll spin the prop so fast, you can nearly take off on that alone. Lighter, safer, long lasting -
I did hear the Earth-X seminar in Oshkosh. It’s very impressive the amount of engineering in that little battery.
If it’s available for your plane, it’s a worth serious consideration.
I have just installed an Earth-X Li-ion in an Express 2000 which is an experimental and the owner loves it. We installed it using the certified models instructions and found there is quite a bit of work to do. We had to re-design the battery hold down system as the battery is much smaller and lighter than the original Concord RG25XC. We also had to plumb a complete vent system and because the battery has a monitoring circuit we mounted an amber lamp and a test button for the lamp in the cockpit. The BMS is a great system depending on how the advisory lamp blinks ie solid, fast flashing or slow flashing tells you what the fault is with the battery. Each battery has a PCB and pigtail to connect to the advisory lamp. One last thing, you need to buy a special battery charger if you need to charge the battery as your regular charger wont do it. All in all not a cheap exercise.
robert,
So you paid the $925 for the ETX900 STC kit vs a $400 RG-25xc ?
Or did you just buy the battery and filled the extra space ?
No just re-designed the hold down section inside the original battery box and filled in the extra space with high density foam. BTW when the customer is sold on a new technology battery, he gets a new technology battery. Sometimes economics doesn't come into it.