Technical question: Is this normal on all batteries?

[andres1227]

Hi all,

Today I noticed that my SoC displayed and the real SoC of the battery when it got down to 36-ish % where pretty much the same.
I went to a fast charging station (Tesla…BTW those short cables are the worst) and payed attention to these values and the displayed one started going back higher than the real SoC.
Here’s a graph of it.

Can anybody speak to it?

TIA!

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[potato]

Yes, there is a buffer on both the bottom and top end to protect the battery. So 100% displayed is less than 100% actual, and 0% displayed is more than 0% actual. (Though we cannot use the buffer... if you hit 0% displayed, you're done driving lol)

So it is a mathematical certainty that the actual and displayed values will be the same somewhere in the middle.

 

[chriserx]

(Though we cannot use the buffer... if you hit 0% displayed, you're done driving lol)

Anyone ever put their batteries in the freezer to get more juice out of em?

 

[ZSC100]

Anyone ever put their batteries in the freezer to get more juice out of em?

Batteries in the freezer does not "get more juice out of em"

Cooling down batteries slows down the electro-chemical reactions so it could help preserve them in an unused state, but otherwise hurts their performance and wastes energy.

 

[SSNutz]

Anyone ever put their batteries in the freezer to get more juice out of em?

Yeah,.I live in WI.... battery energy does work the way you think.

 

[bc1]

Anyone ever put their batteries in the freezer to get more juice out of em?

Yep. I park mine out in the freezer every night this winter. Can't say I see help. Sorry Chris, couldn't resist the obvious. Tried it with old camera and craftsman tool batteries with various restoration attempts with no great success.

 

[chriserx]

Batteries in the freezer does not "get more juice out of em"

Cooling down batteries slows down the electro-chemical reactions so it could help preserve them in an unused state, but otherwise hurts their performance and wastes energy.

It 'worked' for 1990s era alkalines esp in IR remote controls. But the thread reminded me to look up why it could work, cuz I didn't believe it back then, yet it worked most times. Granted we're talking maybe a week of extra use, nothing crazy ¯\_(ツ)_/¯

 

[Maquis]

Batteries in the freezer does not "get more juice out of em"

Cooling down batteries slows down the electro-chemical reactions so it could help preserve them in an unused state, but otherwise hurts their performance and wastes energy.

I built a deck in 1999 using one of Milwaukee’s earliest battery drills. The batteries were Ni-Cad. I had 3 batteries and the only way they could keep up driving screws was to cycle the batteries from the drill to the freezer to the charger then back to the tool. The depleted battery coming out of the tool would not charge because it was too hot. We laid a 400+ sqft deck without stopping.

 

[ZSC100]

I built a deck in 1999 using one of Milwaukee’s earliest battery drills. The batteries were Ni-Cad. I had 3 batteries and the only way they could keep up driving screws was to cycle the batteries from the drill to the freezer to the charger then back to the tool. The depleted battery coming out of the tool would not charge because it was too hot. We laid a 400+ sqft deck without stopping.

Okay, this is a unique case and by cooling the battery you were able to charge it, per limits and safeties that were put into place by the manufacturer. It's the opposite with current lithium ion, I ran into a similar case recently where I had to warm up my batteries because my brother and I were working outside and had about six batteries between three tools being used and after depletion they were too cold to charge. Similar to your situation, the chargers have a thermistor that looks at the temperature before it allows charging. For DeWalt it's for too hot or too cold.

 

[Maquis]

Okay, this is a unique case and by cooling the battery you were able to charge it, per limits and safeties that were put into place by the manufacturer. It's the opposite with current lithium ion, I ran into a similar case recently where I had to warm up my batteries because my brother and I were working outside and had about six batteries between three tools being used and after depletion they were too cold to charge. Similar to your situation, the chargers have a thermistor that looks at the temperature before it allows charging. For DeWalt it's for too hot or too cold.

It also illustrates one of the reasons Ni-Cads are pretty much extinct!

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