EarthEx Lithium battery...are they safe?

Hey
I am considering a lithium battery for my RV-3. My Concorde RG25 is mounted aft of the seat behind a bulkhead, it weighs like 23 lbs. I would love to lighten up the plane, and also reduce weight aft of the CG. One of the EarthEx batteries of nearly the same current rating weighs only 2.5-3.5 lbs...that would shed nearly 20 lbs!
I have heard stories that lithium batteries can have problems if charged incorrectly, or if discharged too far. Several different companies make them, but the EarthEx batteries buy add space from the Vans Forums...I saw their adveretisement here while browsing. Has anyone used them? I would love to hear opinions and reviews.
Thanks
Dave

Hi Dave,

Do a search for "earthx" and you will find several current threads discussing this very thing.

Bevan

Nothing in life is “safe” … no such thing .. the question is .. is the “risk” you take acceptable to you ?
Low risk … insignificant risk .. high risk … But never “safe”

dacronwall said:

Hey
I am considering a lithium battery for my RV-3. My Concorde RG25 is mounted aft of the seat behind a bulkhead, it weighs like 23 lbs. I would love to lighten up the plane, and also reduce weight aft of the CG. One of the EarthEx batteries of nearly the same current rating weighs only 2.5-3.5 lbs...that would shed nearly 20 lbs!
I have heard stories that lithium batteries can have problems if charged incorrectly, or if discharged too far. Several different companies make them, but the EarthEx batteries buy add space from the Vans Forums...I saw their adveretisement here while browsing. Has anyone used them? I would love to hear opinions and reviews.
Thanks
Dave

Click to expand...

It seems, it SEEMS, that if you have a crowbar on your alternator to shut it down over 16.3 volts (that is the B&C device voltage limit) AND mount the battery in a relatively well sealed steel box (one that can get maybe 400F?), and a vent tube overboard should gasses escape, then you are probably OK.

This configuration is yet to be verified, but over voltage is root cause of failures, over temperatures are too, but in your case it would have to be generated internally, so less likely. The earth-x claims, and we have seen another brand do this, that a cell failure is contained in the case. There is possibility of gas venting and case melting both which need the enclosed, sealed and externally vented case.

If you read the hundreds of threads and other online factual information you will come to this conclusion. Again - it has not specifically been tested with the earth-x but covers the known and likely events.

Do your own homework on this and join the information sharing.

An Odyssey battery would save weight too over that 23#.

Fun and education!

Weight and Balance Change?

dacronwall said:

Hey
I am considering a lithium battery for my RV-3. My Concorde RG25 is mounted aft of the seat behind a bulkhead, it weighs like 23 lbs. I would love to lighten up the plane, and also reduce weight aft of the CG. One of the EarthEx batteries of nearly the same current rating weighs only 2.5-3.5 lbs...that would shed nearly 20 lbs!
I have heard stories that lithium batteries can have problems if charged incorrectly, or if discharged too far. Several different companies make them, but the EarthEx batteries buy add space from the Vans Forums...I saw their adveretisement here while browsing. Has anyone used them? I would love to hear opinions and reviews.
Thanks
Dave

Click to expand...

I can only answer the question with a question. What happens to the Center of Gravity with a lighter weight battery? (How does the weight change the weight and balance?) Others have already stated how to evaluate the change of chemistry.

Comment: A lighter weight battery may need to be mounted farther aft to keep weight and balance in an acceptable location. Mounting the battery farther aft will require additional wire weight. The additional wire could add a few pounds back.

I doubt anyone in here can say definitively whether or not they are safe. Battery inside with you? IF it fails...you will be in a very bad situation quickly. Do you wear a parachute and know how to use it?

The question is....would your family agree that 20lbs is worth your life. Then again, this is experimental aviation....someone has to experiment.

What is "safe"?

Lots of RVs out there flying with the small Odyssey PC680 battery, and it's got a proven safety record and weighs only 15.4 lbs.

Interestingly enough, the smaller, lighter (13.2 lbs) PC625 shows to have a little more current capacity

http://www.odysseybattery.com/extreme_battery_specs.aspx

About a year ago my son Peter began using the Aerovltz LiFePo4 battery in his Pitts S-1E. He did it as part of his weight reduction program for IAC competition.
The original lead acid battery was behind the seat. By mounting the LiFePo4 battery to the lower firewall, he reduced the weight of wire alone by nearly 2 pounds. The battery box is lighter, the battery is much lighter, and is right next to the air exit, able to vent directly overboard.
LiFePo4 batteries can be a little weak when cold, but this one gets pre heat with the engine, so that's covered as well.
It's a well thought out arrangement that takes advantage of the lightness and minimizes the risk.
So far, it's been fine.

SHIPCHIEF said:

LiFePo4 batteries can be a little weak when cold,

Click to expand...

If the LeFiPo batery is too cold to start the engine, it has been suggested to turn on a landing light (or other sustained heavy load) for maybe 30 seconds to warm the interior of the battery. When the chill has been reduced, the battery can produce much more cranking amps. This is opposite to how you would use a lead acid battery.

Bevan