Thinking of upgrading to Lithium EarthX battery to go with my UL350i engine. Any suggestions as to model (battery size) and suggestions of what to avoid?

Reason for upgrade is weight savings and because it sounds interesting.



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Thanks for all the feedback! I talked to Kathy at EarthX, decided on a 900 series battery and new box. Ordered the warning light for install now and will order the battery as spring time flying season approaches to maximize warranty.  Won’t be flying much until then and there is no use in just letting a new battery just sit.


Hi Ralph,

First is switching to lithium battery really an upgrade?  Sure they are lighter.  When I performed my weight and balance after switching to the much lighter UL Power I wished I had the two lead acid batteries rather than two lithium ones.  By switching back to lead acid I was able to markedly increase my useful pay load by having more weight up front. That is another reason why I fabricated a permanent tool box to attach to the engine mount. By shifting 20 lbs of weight that I might normally carry to the engine mount toolbox increases the baggage limit by about 50 lbs!  Next, and this is anecdotal, but I later developed rapid  voltage fluctuations  within my system after about three years of use. The cycling was so fast as to not show on the voltage regulator but sensitive systems like my PS Engineering audio panel would reboot itself frequently through a flight. I contacted the manufacturer of the batteries about this an the answer I received was they have never heard of this. Nonetheless, after changing to a lead acid battery system the problem resolved and has not been seen since. Lithium batteries incorporate electronics within them to protect the battery. And, they are difficult to trouble without sophistication testing equipment.  I feel much more confident in the dinosaur system that I can field test than a mystery black box. Just my humble opinion 



I have to confess, the switch is not really an upgrade, it’s for the fun of it. That said, the potential change in w&b is concerning. When I plugged minor changes (10-20 lbs nose reduction) into my worksheet it gave me some interesting results. The issue is not the nose reduction, the major change is that I dropped 35 pounds since I last ran a comprehensive w&b check. Before I almost could not put my plane out of balance, now with lighter pilot and low fuel red flags go up. I will have to review my Excell sheet and review the issue before I go fly again. There just might been a reason to keep my beer gut after all...

Now for the real bad news, I compared my w&b on my iPad to my Excel worksheet on my pc, the results are rather different. Time to do some serious debugging.

Thanks for bringing the w&b issue up, it has helped me spot this programing issue.


Hahaha!!  I'm going to try to see if I can make that one work with my wife.

"Honey, I really would like to start that exercise program.  I really would.  But, Gary showed me how that would throw my w&b off.  So...."


On my cruzer with the Viking 130emgine I found the EarthX batteries failing on the shelf. I installed Ballistic the kind used on snow machine s. These are lithium bit no electronics in them. These are terrific at holding a charge and seems to no popular with the snow crowd.

Like any battery, even with EarthX you should check shelf life to ensure you're getting the latest and greatest.  We purchased our EarthX directly fro the company and have been very happy with their performance, even in temperatures as low as 20ºf.


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