Freezing Batteries to Reduce Overload

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  • Updated 5 months ago
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I am having problems with the mower shutting off due to overload again in the thick patches in my back yard.  I have gotten used to it, but my new neighbor was really interested in the Ego mower (he was using a reel mower) until he saw it shutting off for 5 minutes after every minute or so of mowing.

I could write the book on maximizing battery life and performance, sharpening the blade every mow, mowing dry lawn twice per week, graphite coating on perfectly smooth underside of deck, etc.  I have also figured out that swapping batteries seems to make the mower recover faster and run longer before overloading again. 

Since both batteries were fully charged, and I noticed they come out of the mower much hotter than usual, I decided to stick the other one in the freezer when not in the mower as I swapped them out.  5 minutes in the freezer doesn't even get a hot battery down to room temperature, but much cooler than sitting in a 95 degree garage.  Cooling the battery for a few minutes doesn't keep the mower from overloading, but it does keep it working between shutoffs for a few precious seconds longer.

So, if a little cold is good, is a lot better?  Could I stick my fully charged batteries in the freezer overnight before mowing the next day, putting an ice cold battery in the mower instead of room temperature?  I don't know a lot about battery cells, but I do know that heat is bad so it seems like cold would help extend life and run time, as well as reducing overload shutoffs.
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David Cline

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Posted 5 years ago

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Blue Angel, Champion

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Official Response
David, most freezers would chill the Ego batteries well below the point of optimum performance.

However, a refrigerator usually stays a few degrees above freezing which is well within the operating range of the battery. Sticking your fully charged packs in the fridge over night might get you a little bit more mowing time before the cells get hot.

Do keep in mind, the mower has its own overload protection that will intervene regardless of battery temperature.