I walked into my shop which has no windows so until I turn on the light it is completely dark.
I opened the other day and saw a green glow on the shelf that has never been there. So I walked over and it was one of my batteries and the green light on the side was spinning.
The battery was not on a tool nor was it on the charger just sitting on a metal shelf.
I picked up the battery and it was really really hot. Not burn your hand hot but hot enough that I did not want to hold it.
I pushed the green button and it stopped spinning and shut off.
I put the battery outside for an hour or so and it was no longer hot.
Had not used the battery in a week or so and had not touched the battery since.
Not had a chance to call EGO but that was rather concerning.

I certainly would be interested in their response. I have a few of those in my garage!

My neighbor and I were both having battery issues. I keep mine on the charger in my yard shed. The green light kept flashing, meaning that the battery was too hot. I sat it in the basement fridge for an hour, then it worked fine. I moved the chargers into the basement which is always cool. The problem has somewhat cleared up, but at times the charge seems to run out prematurely. The price for a new 7.5amp/hour battery is as much as I paid for the mower, battery and charger all together. My mower is two years old, if that means anything. I'm experiencing the same issue with the 5 Amp battery to my ego chainsaw.

Possibly thermal runaway?

https://ul.org/research/electr...what-thermal-runaway

I had a battery issue under warranty. The battery fully charged would run the mower for 5 minutes then shut down I would have to wait for a minute or so hen run it another 5 minutes. EGO replaced the battery.

How hot was your shop getting around that time? Some of us have found tool batterys do not like to be stored in an excessive heat environment.

quote:

Originally posted by Jelly:
How hot was your shop getting around that time? Some of us have found tool batterys do not like to be stored in an excessive heat environment.

Shop does not get over 70 degrees unless I have the garage door open for extended period of time.
It’s below ground.

I have the older style that doesn't have the spinning charge level, just green/yellow/red LEDs. I have 1 battery that a transistor failed on the BMS board & caused it to go into a 'long term storage discharge' state constantly. I could charge it, take it off the charger & the green LED would flash constantly & the battery would be dead after 12-24hrs.
I found a youtube guy that narrowed the issue down, bought a couple transistors for ~$3 off ebay & swapped it out. That battery is dated from 2017, and this was 2-3yrs ago.
Sounds like something similar, but your battery also has different electronics than mine, so I didn't dig up the specifics.

Ego batteries have a self maintenance program that runs if a battery is off charger and has been sitting a while, a flashing green light indicates this is happening, maybe that was it.

You can post a question to EGO directly

Link

quote:

Originally posted by HRK:
Ego batteries have a self maintenance program that runs if a battery is off charger and has been sitting a while, a flashing green light indicates this is happening, maybe that was it.

You can post a question to EGO directly

Link

This. If you haven't used the battery in a while, they will self discharge to approximately 40%. Nothing wrong with them. You actually want that, since a fully charged 10 lb lithium battery on your shelf is likely to self immolate.

Thanks. I bet that is exactly what it was doing. Very well could have been flashing rather than spinning.

quote:

Originally posted by Black92LX:
Thanks. I bet that is exactly what it was doing. Very well could have been flashing rather than spinning.

The storage-mode self-discharge is normal, getting hot may not be & is a serious concern with lithium batteries.

I'd be checking the warranty, 56v*2.5Ahr can be pretty energetic if it goes poof - these aren't double-As. On the one that was acting up, it would start self-discharging immediately after charging & would get a little warm. Even when I run the blower in turbo until the battery croaks, they don't get hot.