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Lithium battery cycle life in power tools

Cap'n Steve

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Mar 13, 2021
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The warranty of lithium batteries in power tools is two years or 500 to 1000 cycles. That doesn't seem to support the notion of a high cycle life for lithium. That is a short life at a high cost. Why the disrepancy,,?
 
The warranty of lithium batteries in power tools is two years or 500 to 1000 cycles. That doesn't seem to support the notion of a high cycle life for lithium. That is a short life at a high cost. Why the disrepancy,,?
What discrepancy are you referring to?

The lithium batteries in cordless tools is like NMC which is the explodey lithium chemistry.

Solar systems are using LFP which has 2500 to 5000 cycles but is not as energy dense as NMC plus LFP is heavier which is not an issue in solar battery storage.

Jackery and most solar generators also mostly use NMC with that 500 to 1000 life cycles to 80% capacity.
 
Also, powertools are mostly Li-ion, not LFP.

LFP has a longer lifespan, but is also not capable of providing high currents. Most LFP cells are max 1-3C. For stationary use with big capacity cells not an issue (1C at a 280Ah cell is still 280A) but powertools have much smaller cells, eg 3Ah (3000mAh). They are quite power hungry, especially under load, so it does require cells who can provide higher currents
That's why those mostly are Li-ion (A decent Li-ion cell can handle 5-10C no problem)
 
Still no reason why the cycle life is so low given all the hype about high cycle life for lithium.
 
Ok.
Lipo 500 cycle life is a vast improvement over nicad or nimh or lead acid.
Sure, it isn't infinite, but 500 is 100% usage.
If only 95% usage, it goes up to 1000 or so, if 80% usage, it becomes nearly 10,000...
 
Still no reason why the cycle life is so low given all the hype about high cycle life for lithium.

No reason you're aware of.

The high cycle life "hype" is only for LFP and LTO chemistries. This website deals primarily with LFP to an overwhelming degree. Lithium chemistries in cell phones, cordless tools and most consumer products are NOT LFP or LTO chemistry and have cycle life measured in the 100s, not 1000s.

Review the following if you'd like to educate yourself:

 
Thanks. That helps explain the variation in cycle life. However AC power tools are much cheaper to buy and operate.
 
Thanks. That helps explain the variation in cycle life. However AC power tools are much cheaper to buy and operate.

Right, but they lack portability and require an AC source - completely useless without it. There are costs and penalties associated with the added features.

I hired a guy to build a small pool deck. He shows up, and I point out the outlets and asked if he'd need power off another circuit. The only thing he needed the AC for was his fan and a Lithium charger. He had a complete collection of DeWalt cordless tools with interchangeable batteries. He was proud of them and raved about them being the best set of tools he's ever owned, and he loved the flexibility of cordless operation.

I'm a cheapskate and am very price driven, but I'll pay for value. Sometimes battery power represents a better value. I have 3 regularly used cordless tools - 2X Makita impact drivers and a DeWalt cordless impact wrench - think for installing/removing lug nuts. None of their batteries are interchangeable, but they were all acquired incrementally due to my evolving needs. They are used remotely, and AC powered or pneumatic versions would be useless to me.
 
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