Battery Fire Today

[Low Pass]

Always amuses me how some go to such great lengths to convince the entire group to conform to their level of risk tolerance, while they themselves fly in a plane that tens of thousands of certificated pilots wouldn't set foot. It's all personal preference, and thankfully, for a while yet, we in the US live in a country where the individual has the right to decide what level of risk is right for them. And further, someone's got to put the time on the new products so all the low risk people will feel comfortable using the new technology! ! Why are you trying to stop us?

[Lionclaw]

Confirmation bias.

https://en.wikipedia.org/wiki/Confirmation_bias

Originally Posted by Low Pass

Always amuses me how some go to such great lengths to convince the entire group to conform to their level of risk tolerance, while they themselves fly in a plane that tens of thousands of certificated pilots wouldn't set foot. It's all personal preference, and thankfully, for a while yet, we in the US live in a country where the individual has the right to decide what level of risk is right for them. And further, someone's got to put the time on the new products so all the low risk people will feel comfortable using the new technology! ! Why are you trying to stop us?

[F1R]

Originally Posted by V111Pilot

Hmmmm. As I have earlier questioned L-ion battery safety, and was met with enthusiasm over EarthX (I own one) but I am still weary. Some say that because of their chemistry and protective circuitry they are safe.

Have a look at this though:

http://www.avidfoxflyers.com/index.p...ttery-warning/

Thoughts?

Read post #21 - The first paragraph clearly states that lithium batteries should not be used on a Rotax 503.

"There are many details not here to evaluate all the factors that lead up to this event but ANY lithium battery used with a Rotax 503 should not be used as they are not compatible due to the how crude the charging system are in these engines. To compensate for the design issues, Rotax uses a large capacity lead acid battery with this system (minimum of 16Ah) as a lead acid battery is much more tolerant to voltage irregularly. I would suspect the lithium battery used here was also severely undersized but I do not know that for a fact. "

[BillL]

Originally Posted by F1R

Read post #21 - The first paragraph clearly states that lithium batteries should not be used on a Rotax 503.

"There are many details not here to evaluate all the factors that lead up to this event but ANY lithium battery used with a Rotax 503 should not be used as they are not compatible due to the how crude the charging system are in these engines. To compensate for the design issues, Rotax uses a large capacity lead acid battery with this system (minimum of 16Ah) as a lead acid battery is much more tolerant to voltage irregularly. I would suspect the lithium battery used here was also severely undersized but I do not know that for a fact. "

Just where is this magic list of "approved" applications for EarthX - This clip is taken from their marketing brochure. I did not find any limitations or warnings in this document. It certainly implies ROTAX is approved. So, just what is a "bad" charging system, how long does a diode have to be bad in a good one to switch "smoke on" . This subject has not been adequately addressed - YET.

So which statement is clear??

EDIT: Searching EarthX website - it is clear that some applications are not compatible with a LiFeP battery of any brand. EarthX states this in several places. They also recommend that you contact them to discuss your system to see if any incompatibility exists. This is sound advice. I was stuck on the " approved" term and mistakenly so, as EarthX does NOT use that term in reference to experimental applications. I apologize for getting this off in the weeds with this particular issue.

[rmartingt]

Originally Posted by BillL

Just where is this magic list of "approved" applications for EarthX - This clip is taken from their marketing brochure. I did not find any limitations or warnings in this document. It certainly implies ROTAX is approved.

Rotax makes a lot of different engines. The batteries in question may be approved with a 912iS (for example) but not on one of the two-stroke models. Approval for any given one of a manufacturer's products doesn't grant unlimited approval for all of that manufacturer's products.

[BillL]

Originally Posted by rmartingt

Rotax makes a lot of different engines. The batteries in question may be approved with a 912iS (for example) but not on one of the two-stroke models. Approval for any given one of a manufacturer's products doesn't grant unlimited approval for all of that manufacturer's products.

Yes, but EarthX talked about "approved" - I went back and looked at the website http://earthxbatteries.com/engine-ch...hium-batteries

This link addresses the AC content that is ok and not-ok. I would suggest that the marketing literature is misleading and worst, and just inaccurate at best.

Kudos for EarthX to have posted the waveform issues, now they can let us know about what happens with a failed diode on a 3 phase alternator.

[EarthX Lithium]

Originally Posted by BillL

Just where is this magic list of "approved" applications for EarthX - This clip is taken from their marketing brochure. I did not find any limitations or warnings in this document. It certainly implies ROTAX is approved. So, just what is a "bad" charging system, how long does a diode have to be bad in a good one to switch "smoke on" . This subject has not been adequately addressed - YET.

Dear BillL,

I am sorry the marketing brochure is unclear and this is not our intentions. It is impossible to have everything about a product listed in a small brochure.

We do list Rotax engines has approved our batteries but they have many, many engines that span years of production and the 503 is one that is not approved for use which we clearly state on our website in BOLD RED PRINT, also stated in the manual, and we also have a detailed Fact Sheet to outline why to clarify the reasons as we do try and provide information to our potential customers to help make an informed decision. http://earthxbatteries.com/engine-ch...hium-batteries


We also have Continental Motors that have approved our batteries for use and they have many, many, engines that span years of production including certified engines. Saying that Continental Motors approves our batteries does not mean you can use the experimental batteries with your certified engine as a bypass for FAA approval in a certified aircraft.

We also have many original equipment manufacturers (OEM's) that use the EarthX line in their experimental aircrafts but saying they approve the EarthX brand does not mean you can then put them in a certified aircraft from the same manufacturer.

The charging system of any aircraft is a very important component and no matter what manufacturer or part you use, it is very wise to research the application in depth before using it. This includes your alternator, regulator, and the battery, etc. You can always contact a manufacturer prior to purchase or use of their product to verify the application is correct for your system.

Hope this helps clarify things.

[ChiefPilot]

The key item I don't understand is how the BMS failed to protect the battery.

I accept that the Rotax charging system is outside the parameters for what EarthX considers acceptable. I'd add that a runaway/overvoltage charging system on a Lycoming seems like it would be outside those parameters and would be one reason why the BMS is in place.

I have no dog in this discussion - I do not have or intend to purchase an EarthX battery for a variety of reasons - but find the engineering questions interesting.

[EarthX Lithium]

Originally Posted by ChiefPilot

The key item I don't understand is how the BMS failed to protect the battery.

I accept that the Rotax charging system is outside the parameters for what EarthX considers acceptable. I'd add that a runaway/overvoltage charging system on a Lycoming seems like it would be outside those parameters and would be one reason why the BMS is in place.

I have no dog in this discussion - I do not have or intend to purchase an EarthX battery for a variety of reasons - but find the engineering questions interesting.

Thank you for the question as this illustrates perfectly why it is so important to educate yourself about using a product and it's applications.

If you are referring to this particular issue at the beginning of this thread, we have no idea what brand of battery, the spec's or any details about any type of built in protection, if any, with the battery that had an issue. But all products are built with limitations and that is why, especially in the battery world, there are application charts as one size battery does not fit all applications.

If you are referring to the thread where the EarthX battery was used in the Rotax 503 which caused a cell to rupture and the electrolyte came into contact with the plastic and caused a chemical reaction which made the plastic appeared melted, I can address that:

1- The battery used was 4 times smaller in capacity than the recommended lead acid battery for the engine by Rotax and also not one of the aircraft specific batteries that are recommended at EarthX for aircraft use. Using an undersized battery for any application causes extreme stress to the battery, whether it is lead acid or lithium. The reason for application charts is based on the ability and design of the limitations of a battery.

2- The user did not heed all warnings from EarthX's website to not use any lithium battery with this engine and charging system.

3- The electrical wiring on the plane was done incorrectly.

So your question is, why did the BMS not protect the battery even when all else failed? The BMS in this battery was designed for a motorcycle back in 2014 when this occurred. The rate or speed of voltage irregularities was too quick for the BMS to block and too erratic (which is why we warn not to use it). Add the amount of over stressing due to being such an undersized battery did not help.

Even with all the misuses (or abuses) here, the battery did not catch fire, did not "explode" nor did it cause smoke. This is what we would consider a catastrophic failure and a cell ruptured inside which released the electrolyte which once in contact with the plastic, will cause it to appear melted.


As a manufacturer, you have no control over what someone does with your product. The best you can do is try diligently to explain it's used and limitations. If you ever have questions about a product and it's use in your system, call the manufacturer and get clarifications.

[jj13]

Originally Posted by ChiefPilot

The key item I don't understand is how the BMS failed to protect the battery.

I accept that the Rotax charging system is outside the parameters for what EarthX considers acceptable. I'd add that a runaway/overvoltage charging system on a Lycoming seems like it would be outside those parameters and would be one reason why the BMS is in place.

I have no dog in this discussion - I do not have or intend to purchase an EarthX battery for a variety of reasons - but find the engineering questions interesting.

I'm not sure how the BMS would protect the battery except by disconnecting itself from the buss. That would then allow the voltage to go even higher possibly damaging expensive AV equipment. Having over voltage protection built into plane's electrical system maybe a better solution.