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Any experience with Lithiumax start batteries?

Flow

Member
Hi folks, has anyone had any experience with these batteries. We don't have access to EarthX downunder.

Specifically any comments on electrolyte decomposition / LiO2 or O2 generation and swelling / case cracking and the quality of the BMS of these items. (Could case swelling also be related to altitude?)

I am running an 'electric' aeroplane so the shut down mode would also be of interest!

They talk about a failure rate of less than 1% which seems very high to me.


https://www.lithiumax.com.au/shop
 
If flying had a 1% accident rate I'd find another hobby! :eek:
(not sure why anyone with an all electric airplane would also run an 'experimental' battery)
 
Earth x will auto disconnect under some circumstances to protect itself, probably not a desirable feature for electrically dependent AC.
 
If flying had a 1% accident rate I'd find another hobby! :eek:
(not sure why anyone with an all electric airplane would also run an 'experimental' battery)

+1 More common sense from Walt. It's the "Experimental" category but in reality it doesn't pay to get too experimental. I see the OP is from New Zealand....there's a LOT of very inhospitable terrain in the Land Of The Long White Cloud.
 
Thanks guys, it seems they have a number of these in aircraft in Aus at the moment including a number of Extras. These have been running for 5 year at this point. Small sample size but will have a chat with the operators shortly.

These have an 8V for the Race model and 85C cut out. Or an 11.5V cut out for the Restart. The ECU has a 10.5V cutout. I have a PC950 Odyssey in there at the moment but it only has a max operating temp of 45C while the LiPo have a 65 max continuous and 85 max peak. Cooler is better ofc. So I think this should be an improvement. I will be HTCing the exhaust soon and building an insulated battery box as well. I am also running a bus side capacitor and a switching R/R for open circuit battery cut offs.

Has anyone actually used these? I have seen all sorts of issues with the EarthX as well.
 
I have picked one of these up. https://www.lithiumax.com.au/produc...-ultra-light-engine-starter-battery-pre-order

I didn't go for the Restart 7 as it has an 11.5V cut out for under-volt protection. The ECU has a cut out at 10.5V so I would prefer to keep a bit more in the tank in case of an alternator failure. At 25A with everything running the 45AH Race 7 should give me a comfortable 60 min flight time without charging.

I have a question about how to potentially improve reliability of batteries with BMSs in the high vibration aviation environment.

What do we think about injecting an expanding fire retardant silicone foam or a silicone conformal coat like this into the casing. https://www.amazon.com/MG-Chemicals-422B-340G-Silicone-Conformal/dp/B008O9YGQI
 
I have picked one of these up. https://www.lithiumax.com.au/produc...-ultra-light-engine-starter-battery-pre-order

I didn't go for the Restart 7 as it has an 11.5V cut out for under-volt protection. The ECU has a cut out at 10.5V so I would prefer to keep a bit more in the tank in case of an alternator failure. At 25A with everything running the 45AH Race 7 should give me a comfortable 60 min flight time without charging.

I have a question about how to potentially improve reliability of batteries with BMSs in the high vibration aviation environment.

What do we think about injecting an expanding fire retardant silicone foam or a silicone conformal coat like this into the casing. https://www.amazon.com/MG-Chemicals-422B-340G-Silicone-Conformal/dp/B008O9YGQI
The aviation approved Lithium batteries (B787, Biz Jets) have their own vault or metal case to control a thermal runaway. I had a Samsung S5 cell phone. Loved i. You could pop the back off, put a battery in quickly. I had a few spares and could charge them outside the phone. However over time I noticed one starting to swell, It still worked and charged, but was leery of it. I stopped using it. For fun I went outside with a nail on a poll punctured it. As I stood back and a little smoke came out, then got more intense. Then it went into total conflagration. It was a spectacular release if energy. I have a new found respect.

With that said your idea of surrounding it with HT silicon, don't know. It is an interesting idea, with the Cons being more volume and weight, but might have merit. Would that make the battery run hotter? Would it contain a runaway lithium meltdown? I think any battery can have a bad day, so respect them. AGM or FLA batteries are a little less likely to melt down. By the time you add silicon or steel metal fire shields the weight advantage is gone.

You would have a real problem if you lost your electrical and had a raging lithium battery fire. As indicated by the commercial aviation industry (Bizz jets, Airlines) approved Lithium batteries are in metal cases. I don't know the material but it is likely steel (SS) or titanium.

As far as power for your critical items. ECU, you should have dual electrical system as you probably already know. The Li Ion would be for start and main bus. Your essential bus should run on an independent bus isolated from the main. If using one alternator you will have to charge the essential bus with that one alternator. There are ways to do that. One is a DC to DC battery charger. If you get fancy two alternators and two batteries is the best, but again adding weight and complexity.
 
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If flying had a 1% accident rate I'd find another hobby! :eek:
(not sure why anyone with an all electric airplane would also run an 'experimental' battery)

Sorry, Walt, it is obvious that you personally do not like EarthX...and that is fine.

You should, IMO, not cherry pick information. Yes, EarthX is "an experimental" battery in most cases. The DO have an FAA approved model as well.

You also state, in another post, that the EarthX BMS will disconnect under certain conditions. That is true, however, that should not happen until 16 volts is sensed...and the over voltage protection should have already taken the alternator off line.

I have spoken with B&C and EarthX about this recently, as I have dual EarthX batteries and dual B&C alternators/regulators. The B&C regulators, with built in OV protection, should trip the Alt field circuit around 15.6 volts and the response time is in the tens of milliseconds. The EarthX BMS takes the battery offline at 16 volts, AFTER a TWO SECOND delay. So, in a normal system, the OV protection will trip that circuit long before the BMS will disconnect.

I know of one case where it did not happen this way, and damage was caused. I have not heard of anyone explaining, definitively, why it happened...I would really like to know.

Point is, maybe it would be better to present all the facts and let people decide for themselves instead of presenting some of the facts to support a specific bias.
 
SNIP

You also state, in another post, that the EarthX BMS will disconnect under certain conditions. That is true, however, that should not happen until 16 volts is sensed...and the over voltage protection should have already taken the alternator off line.

Yep - that is what is supposed to happen. My one experinece with an alternator wired to an external output soleniod that was set to trip on over voltage was that this protective function failed when needed. The plane had two PC-625 batteries on line so they absorbed the voltage/current spike long enough for me to recognize what was going on (and this took a lot longer than I care to admit) - in short I was the over voltage protection that day.

The batteries provided 2+ hours of IFR flight without the alternator, so this was, as are most alternator failures if you still have a battery(s), a non-event.

I too consider the EarthX BMS tripping the battery off line as a weak link. I assume (but don’t know) the BMS resets once the over voltage condition is removed, but for an electrically dependent engine and/or all electric panel in IFR, the power disruption will be problematic. I suggest if you are using an EarthX you isolate the avionics and other voltage sensitive equipment and test (if possible) your alternator over voltage trip. I suspect this will be difficult for most running an alternator that has this protective function built into the internal regulator.

If you cannot test this feature and have an electrically dependent engine, I recommend looking at additional backup power to keep the fan running. I say this even though I carefully design backup batteries out of my airplanes.


Carl
 
Bottom line, everyone is looking to Lithium to save a few pounds.
Gotta ask yourself... is the reward worth the risk?

I think it was Dick VanGrunsven that said, easiest way to reduce the weight of your aircraft is to go on a diet :eek:
 
More info

After additional research, it looks like B&C changed the OV threshold on the new LR3D regulator to 16.25 volts.

I would be curious to see if the this was the regulator being used in the case of BMS disconnect.

If this regulator was used, then it is possible that the BMS COULD disconnect before the OV protection, yielding the failure in that system.

I will try to reach out and report back...
 
... I suggest if you are using an EarthX you isolate the avionics and other voltage sensitive equipment and test (if possible) your alternator over voltage trip. I suspect this will be difficult for most running an alternator that has this protective function built into the internal regulator.
...
Carl, indeed, this is a good idea. I wonder if this could be tested even with an internally regulated alternator on the ground with an external power supply. My PP documentation says it has an internal crowbar overvoltage protection system. Unfortunately it doesn't say the voltage it uses to trip the crowbar.

https://planepower.aero/wp-content/uploads/2020/06/AL12-EI60-B-Install-Instructions-1 said:
Troubleshooting Instructions
Alternator is equipped with an intemal crowbar over-voltage protection circuit which will disable alternator if an over-voltage condition is sensed.
If 5-amp enable circuit breaker trips from an over-voltage condition in the alternator:
1. Reset 5-amp enable circuit breaker and continue operation.
2.lf 5-amp enable circuit breaker trips again, land as soon as possible and investigate cause.

Seems like if the alternator is on, and you have a bench power supply hooked up to the system, and you start increasing the voltage, the alternator's ovp should trigger. I'm not planning on trying this, cuz I'm chicken, but perhaps a call to PP would let us know a way to test this.
 
Plane Power OV works...

As an FYI - I accidentally created a scenario resulting in a rapid load shed/dump and the PP Alternator OV Crowbar circuit responded as hoped -- tripped field breaker off at ~15.723 Vdc. < 150mS.

PP Alternator -- ALT 5020T / 99-1012
 
BMS does NOT disconnect battery for an Over voltage situation

Sorry for not seeing this post last year but I was searching for another topic when I saw this. Please note, the BMS does not disconnect for over voltage with an EarthX battery, however, some brands do so it is important to understand what the BMS does. The BMS disconnects when the battery has been drained of 95-98% of its energy (which means less than a minute before 100% drained). This is no different than you have used all of your fuel, when it is gone, it is gone. Details on how the BMS works is located at www.earthxbatteries.com.

If you are experiencing over 16V, your regulator has failed. In an over voltage situation, your charging system has over voltage protection which is designed to save all of your electronics, including your battery. If this voltage climbs, your over voltage protection has failed. In the event this fails, the battery itself has the ability to limit the current coming into it but still remain part of the system. Again, it does not disconnect. If your voltage climbs over 40V, you will damage all of your electronics in your aircraft (very expensive lesson) if you as the pilot, the last resort, do not take your alternator offline.
 
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