Earth X battery?

[Low Pass]

One data point. Ran a Shorai LiFePO4 non BMS in my -8 for about 3 years and 250 hours. It performed excellent. Last fall, I began to notice issues. Long story short, it failed on a local flight. I first noticed a "sweet chemical" smell. Voltage wasn't quite right. Then it snapped - battery. Turned off the alternator field. I was near a field and landed within 2 minutes, shutdown, uncowled as fast as I could. The battery had swolen and pushed the top off the battery case. It wasn't hot or emitting a lot of gas at that time. But I did get it out of the plane with minimal delay. Had I not smelled the gas and kept motoring along, who knows.

Not an EarthX. No BMS. Just a LiFePO4 battery failure. Result - No heat damage, lots of gas, battery case failed. I am back to lead acid as my mission is reliability, not max performance.

I'm sharing this for people to understand what events may happen with an LiFePO4 battery failure. These batteries have unique characteristics and care needed for proper lifetime operation. I still highly recommend this brand. They will sell you a BMS or a non BMS battery (call the distributor). But make sure you know the details of maintaining and operating before installing.

 

[lr172]

lithium batteries (any chemistry) absolutely require a bms to charge correctly. The bms can be part of the charging system or integrated with the battery. The battery can be easiliy ruined by connecting it directly to a dumb power source like an alternator. When charging multiple cells in series, the first cell that reaches the cut off voltage stops the bulk charge and then the bms uses various techniques to balance the remaining cells . There is really no option not to use a bms with lithium unless you are trying to destroy things.

there are many non bms Li fe batteries sold without bms's and perform just fine without the cell balancing. Shorai sells a lot of them and several have posted here about installing them. Continue to believe that the key features for use in planes are those that prevent the things that can create issues, such as over volt, etc. Though i understand the long term benefits of cell balancing.

 

[lr172]

One data point. Ran a Shorai LiFePO4 non BMS in my -8 for about 3 years and 250 hours. It performed excellent. Last fall, I began to notice issues. Long story short, it failed on a local flight. I first noticed a "sweet chemical" smell. Voltage wasn't quite right. Then it snapped - battery. Turned off the alternator field. I was near a field and landed within 2 minutes, shutdown, uncowled as fast as I could. The battery had swolen and pushed the top off the battery case. It wasn't hot or emitting a lot of gas at that time. But I did get it out of the plane with minimal delay. Had I not smelled the gas and kept motoring along, who knows.

Not an EarthX. No BMS. Just a LiFePO4 battery failure. Result - No heat damage, lots of gas, battery case failed. I am back to lead acid as my mission is reliability, not max performance.

I'm sharing this for people to understand what events may happen with an LiFePO4 battery failure. These batteries have unique characteristics and care needed for proper lifetime operation. I still highly recommend this brand. They will sell you a BMS or a non BMS battery (call the distributor). But make sure you know the details of maintaining and operating before installing.

so glad this was a manageable isuue and no major damage. Good that you understood the risks and shut off the alternator.

 

[ve0kog]

there are many non bms Li fe batteries sold without bms's and perform just fine without the cell balancing. Shorai sells a lot of them and several have posted here about installing them. Continue to believe that the key features for use in planes are those that prevent the things that can create issues, such as over volt, etc. Though i understand the long term benefits of cell balancing.

balancing is a side benefit of bms. its main job is to prevent permanent damage from over charge or over discharge of any single cell in the battery pack. Shorai has all kinds of caveats regarding non-BMS batteries https://shoraipower.com/charging . they don't work "just fine" when connected to the alternator without the BMS. It's a death sentence for the battery

Shorai is probably happy to sell bunches of them though, due to wide spread damage from wrong type chargers and overdischarging.

 

[bjdecker]

balancing is a side benefit of bms. its main job is to prevent permanent damage from over charge or over discharge of any single cell in the battery pack. Shorai has all kinds of caveats regarding non-BMS batteries https://shoraipower.com/charging . they don't work "just fine" when connected to the alternator without the BMS. It's a death sentence for the battery

Shorai is probably happy to sell bunches of them though, due to wide spread damage from wrong type chargers and overdischarging.

What most people do *not* comprehend is how an alternator / generator recharges a battery vs a dedicated “charger.”

It’s not a slow, deliberate act by a charging circuit — it’s a violent, take as much current as the internal impedance of the battery will allow…and then keep on taking it — electrolyte and plate life be damned.

I would NEVER install a non-bms battery in any vehicle - especially one powered by an alternator. Dynamo/Generator - maybe - if the running voltage was as close to the float voltage as possible.