Lithium (LiFePO4) batteries

[4CA]

Hi all,

Has anyone experimented/fitted a Lithium battery for engine cranking and/or pre-rotator? I understand that there's potential issues with various alternator configurations and ability to charge at the higher rates etc, plus the fact that they all have a 'Battery Management System' that can technically isolate the battery if it detects an overcharge problem etc, but on the whole they seem like a viable option now and are so much lighter..

Full disclosure, I also have an issue with my current battery that when I hit the pre-rotator, it drops the voltage so low that the engine tries to die. Great for practicing rotor management, but I reckon there's a better solution out there.. either committing to an Odyssey C950 or going Lithium..

Interested in any feedback you may have?

Paul

[Waddles]

G'day Paul,

Paul C has a gyro for sale on this forum that has a Life Po4 lithium battery with BMS installed. He'd be the man to talk to.

Waddles.

[4CA]

Thanks Waddles,

I'll chase down a contact number for him.

Cheers

Paul

[RossM]

When I hit my pre-rotator it draws 400 amps. The volt meter drops back to nil. My gyro has an EA81 motor.
(after the rotor gets going the pre-rotator only draws 300 amps)
Yes LiFeP04 batteries would be good, as I believe that they can keep up the voltage when hitting ore-rotator. The battery management system should protect from overcharge, under voltage and heat. I do not think that they are to get wet either.

Rick may be able to add a comment, as he is aware of two installed on gyros heating and starting to smoke. I think that one of the European make gyros started to come with these batteries, but have stopped using them because of chance catching fire.

Regards...Rossco

[RickE]

Thanks Waddles,

I'll chase down a contact number for him.

Cheers

Paul

G’day Paul, I’ve just sent you Paul C’s mobile number via PM.

The Germans have put out a service bulletin recalling a specific brand of lithium battery from their gyros and I’m aware of a couple of Magni’s that had issues with lithium batteries as well.
I also know that there are many lithium batteries being used without a problem.

Cheers. Rick

[4CA]

Thanks Rick, appreciate that.

I had a good chat with Paul C yesterday arvo and he was able to give me some good intel on the LiFePO4 battery he has experience with.

Really hard to ignore the power to weight side of things, plus it looks like they don't suffer from the calcification issues the AGM batteries have if being stored for a while between usage etc. My only real concern is the continued use of the EJ22 alternator and it's regulator keeping the charge rate at around 13.6v which from most of what I have read is sitting right at the bottom end of what is good for the LI batteries.. that said, Paul C didn't seem to have any issues with that side of things.

I'll keep doing some research, but either way, I need a better solution that what I've got currently..

Paul

[4CA]

Sorry Rosco,

Forgot to thank you also. Appreciate the additional info. Yet to find out what the current draw might be at this end, but it's obviously substantial given yours and I can see why it kills batteries overtime.

Love the idea of using the LiFePO4, I just need to commit to it...

P.

[4CA]

Hi all,

Thought I would close the loop on this one. I ended up purchasing the Lithiumax RACE9+ LiFePO4 battery as recommended by PaulC.

Absolutely fantastic result.

It's significantly lighter than the AGM battery, and it pumps through the pre-rotator without any significant voltage drop causing issues with the EJ22.
The alternator keeps it at 13.6V, however pressing the LCD indicator after test flying, it was reading 14V. Very happy with the way it has turned out.

For info, it's definitely a more expensive option, costing around AUD$1,000 all up with the added charger and aluminium mount, but it was essentially a plug and play solution and has completely resolved the voltage drop issue I was having with the AGM battery.

Did an hour of test flying on Australia Day without any issues so couldn't be happier.

Cheers

Paul

[RossM]

Thanks for the update, Paul.
Did you have to do much for different battery mounting?
Keeping the battery dry, or any other precaution that may have to be taken when using a LiFePO4 battery.
Cheers...Rossco

[chook]

Hi Gents.
A couple of us in Bindoon W.A have been successfully using SPLFP-20R super sport Lithium (LiFe PO4) 360 CCA motor cycle batteries for over 2 years now in a couple of ELA's. They have been reliable and work straight off the Rotax charging systems without modification. I purchased mine in August 2021 for $250 but note now that they are at the $320 mark. They require a 14.4 - 14.8 charge voltage and between 3 and 12A max charge. Sorry I don't have the weight but probably less that 1.2 kg so very happy with them as they spin the Rotax's over very easily.

Just a caution - NEVER use a desulphation charger (eg CTEK) to charge these lithium batteries. These chargers incorporate a high voltage pulse stream which destroys the internal battery "smarts". An old battery charger with a heavy transformer which doesn't have higher volt and amp ratings that the battery can handle is fine for the odd "top up".

Rossco the battery comes with stick on foam patches which can be used if required to buffer the battery firmly within the original battery cage. Our batteries were fully sealed and had no protection from water requirements.

Regards........Chook.

[4CA]

Hey Chook,
Yeah, I bought a charger from Lithiumax at the same time as I read they needed a different charger. Haven't needed it yet as it seems to be holding it's resting charge without any internal losses which admittedly is one of their sales pitches for low usage equipment etc. My concern was that the alternator wasn't going to give it enough amps to keep a descent minimum charge so bought the charger to top it up each day if needed. So far so good though.

Rossco,
They didn't have anything in the paperwork about not getting the battery wet perse, and it all looks well sealed. I reckon it would be splash/rain resistant without any drama, but maybe they have issues with Jet Ski's or the like that may end up inverted etc? I've added a pic of it mounted on my machine using their aluminium mounting box/cage.. it's a nice tight fit when bolted down to the frame, without any movement. I had some foam around it originally, however it was such a snug fit in their box that I had to remove it.

The cranking power really is a cut above the other batteries I've had but it will be interesting to see how long the pre-rotator lasts. I'm still hand turning the blades before I jump in which definitely reduces the loads on the pre-rotator/controls/mast, and maybe a soft start would be the way to go in the future but for now I'm happy. I have been giving it a 3-4 second burst on the pre-rotator followed by a similar time between subsequent bursts for cooling.. seems to be the way to go.

I'm definitely a convert

Paul

[RossM]

Paul
900 CC should turn rotors no problem (I guess) without dropping voltage?
Rossco

[RossM]

Came across a sight all about batteries.
https://batteryuniversity.com/articles

Rossco