Lithium batteries

[ykachuro]

Brian, thanks a lot for sharing a picture if your install! I see a couple of innovating ideas in this implementation and have a couple of questions.
— what’s the insullating material you are using?
— is the bonze/copper bracket to the negative terminal meant to be the main ground connection to the airframe? Is it meant to also help with retaining the battery in the box?
— which model EarthX battery is this? Is this the box EarthX sells?
— why two grounding bands to the engine?

Would you mind sharing a few more pictures of your engine install, including your alternator installation, the air induction box, firewall penetrations)?

Thanks!

And Happy New Year!

[rv10builder]

Photo attached of my EarthX installation. Not yet flying, but the O-320B2B cranking power is crazy. Failure mode of this brand is smoke, though that concerned me enough to place on engine side of the firewall. SD8 alternator with crowbar OV protection should be a non-issue for damage, but temperature wise I located where I believed to be the best while also insulating the battery box.

[JimParker256]

To me, the one area where a battery "shut-down" due to low voltage might be a real issue is if it happened at a remote location with no services. Without a way to recharge the battery, one might be stranded. But then I read about the EarthX "Jump Pack", which would completely mitigate that concern. (See it here: https://earthxbatteries.com/shop/earthx-jump-pack) At $129, carrying one as a "backup" for emergencies like this seems like a no-brainer, and you can also use it in your car, or to keep your cell phone, tablet, GPS, whatever charged up.

On "another forum", I read about a whole bunch of guys who fly Super Cubs up in Alaska, using a "jump pack" like like this as their ONLY source of electrical power. They have no electrical charging system in their airplane, specifically so they can be exempt from the transponder requirements, etc. (Questionable logic in my opinion, but...?) One guy claims he routinely makes 6-8 engine starts off his (he has an O-320) before even bothering to recharge the jump pack. Personally, I'd be a lot more conservative than that, but every one of the guys who are using them swear by them!

[ykachuro]

Colin, thanks! Good link to a cubcrafters discussion. I take it back what I said that these are meant to be plug and play. They are and they are not at the same time. The choice to use this fairly new tech need to be an educated one. I am trying to do just that. I should’ve aded to my analysis that my airplane will not be flight dependent on power and will be day VFR only. I will have dual pmags, mechanical fuel pump and probably a built in backup battery for the airspeed/altitude/attitude indicator. If the lights go out, I should be able to continue my flight to a nearest safe landing strip. Right now, I don’t see how I can possibly have a catastrophic failure of a lithium battery with the set up that I have in mind — crowbar protection is guaranteed to take the alternator offline if it/the regulator start misbehaving and I will have plenty of time to complete my flight in a safe manner. Btw, the crowbar trigger won’t take the battery offline, just the alternator.
However, putting the battery behind the firewall so that the smoke can vent if that ever happens might be a good idea in any case and it costs nothing. Or have the battery in a containment box vented outside if I put it in the cockpit.
The cubcrafters discussion underlined one point that I was making as well — it may be a big disadventage to have a battery with a built in BMS that takes the battery offline when its voltage is getting low. Especuially if the airplane is as electrical power dependent as the CC. Shorai and other batteries that are lacking built in discharge protection should stay on until their ultimate demise from being over discharged.

[JimParker256]

There was an excellent article by Jared Yates in Kitplanes published Dec 2017. Well researched, and in-depth, but easily understandable by us laymen. You may have to be a Kitplanes subscriber to access the link, but here it is anyway:.
Understanding Lithium Batteries: http://www.kitplanes.com/issues/34_12/b ... 972-1.html

[MyronNCallaham]

I’ve had really good service with the Odyssey

[colin]

The Boeing 787 battery uses cobalt Li IOn batteries which is the chemistry in our cell phones and laptops and is more spectacular event when it fails that phosphate . Phosphate Li ion failures don't look like flares going off like our cell phones (Samsung 7) but still burn . The charging is controlled at the cell level in any Li Ion battery pack of any chemistry or voltage. I'm sure the Earth X built in controllers have all the safety precautions or they would be in the news allot. The individual cell voltage is controlled between 4.2 and 1.2 volts. Going over 4.2 causes an "event" and going below 1.2 kills the cell. Individual cell temperature is also monitored for high heat. If you have a Light Speed or electronic ignition see the link below . So I would have to confirm with EarthX how much overvoltage their built in charger can handle. It may or may not be an issue. That being said over voltage protection is a good idea in any case.

http://forum.cubcrafters.com/showthread ... y-Cautions

[Barry]

My 2 cents,

I have used the Odyssey 680 in 3 different aircraft, RV6, RV6A and Avid Magnum. The RV6 was installed on the cold side of the firewall and the Magnum on the hot side. No issues either way and great life from both. Plenty of cranking power for any O320-360. Cold starts without preheat was iffy, but I try never to be in that situation. I maintain with a Battery Tender which is also a great product.

The specs of the EarthX are impressive such as weight and more CCA. But very pricey.

Both are great products, but I feel bang for buck goes to Odyssey.

Barry

[jamesmil]

At the risk of sounding like a smart—- I like to use the KISS method as much as possible on things, the odyssey is a totally sealed conventional battery that uses standard chargers and charging systems and has proven to be trouble free , I have used them in airplanes and race cars with good service. Also the B/C 8 amp alt, comes with the regulator and crowbar.
Again not trying to stir up any confusion just throwing in my 2 cents worth which the last time I checked it was worth 2 cents

[ykachuro]

The containment box vented outside the airframe is a good idea. This is what EarthX recommends for installs on the cold side of the firewall. I may do it if I go with a lithium battery in the cockpit.