Lithium-Ion Battery Maintenance News & Opinion

Lithium-Ion Battery Maintenance: 5 Performance Killers

I like to test the limits of tools, and yeah, the occasional explosion is fun for me as well. So when it comes to the issue of damage, I’m your man to talk about it. In this segment, we’re talking about Lithium-Ion battery maintenance; specifically some things that can damage your battery.

Cordless power tools have come a long way since they first came out. They’re more powerful, run longer, and some are giving corded tools a run for their money. Technology has improved the cordless tool itself and perhaps the most obvious is in the Lithium-Ion battery that powers it. Cordless convenience has always come at a cost, so protecting the investment you or your business has in its tools is important. That includes being sure that you are using proper Lithium-Ion battery maintenance . On that note, let’s look at 5 things that hurt Lithium-Ion battery performance.


Lithium-Ion Battery Maintenance: The Top 5 Things that Hurt Run Time, Power, and Life


Heat is the number one killer of batteries and the biggest challenge in Lithium-Ion battery maintenance. Heat is generated when the chemicals inside the battery cell are charging or discharging. The pack cools down when the reactions are stable. The highest temperatures are generated during the aggressive discharge of more powerful tools. It’s not a linear curve of more power = less run time. A 4.0 amp hour battery may reach 99% of its run time potential on a work light, 95% on a drill, and only 90% on a rotary hammer. This is simply the result of the amount of heat being built up.



On the other side of the coin, a lack of heat can also affect the run time of a battery in a negative way.Users that work in cold climates typically won’t get the run time or power that their warm weather brethren do. Check out our 12V Impact Driver Shootout where we performed a cold weather test. The drivers we tested were limited to 60% – 80% of their normal speed after bring exposed to -10 degree temperatures for an extended time.


If you break open a cordless tool battery pack, you find what looks like a bunch of oversized AA batteries in there. These are the battery cells that power the pack. They’re made up of mainly a Lithium-Ion coating, the cathode, and the anode. Vibration of these cells will negatively affect the life of your battery. With really aggressive tools like reciprocating saws and rotary hammers, a lot of vibration is introduced and the life of the battery tends to be reduced in these tools.



We all know that water and electricity don’t mix. That’s true inside batteries as well. While most batteries can handle humidity well, direct moisture can be a major problem. Once inside the pack, packs built with poor quality materials can easily and quickly corrode, rendering your battery useless in a matter of days. Even the best batteries can’t stand up to water forever though.

Depth of Discharge

While Lithium-Ion Batteries do not have “battery memory” like their predecessors, the level of discharge does affect the lifespan. A study published by Cadex Electronics stated that a typical Lithium-Ion battery would have a 50% longer lifespan if it were charged after 50% discharge instead of fully discharging. Charging following only a 25% discharge resulted in a 67% longer lifespan over over full discharge.

*Note – this study was performed on laptop batteries. While both laptops and tools run on the same technology the build is different. I would not expect the lifespan to mirror the laptop study exactly, but it does serve to show how varying the Lithium-Ion battery maintenance in terms of discharge can affect the life of the battery.

While I let you digest these major sources of damage to your Lithium-Ion batteries, I’ll be working on the second part of this article – Lithium-Ion Battery Maintenance Tips. Be on the lookout for that article in the next couple of weeks to see some practical ways that you can extend the life of your investment.

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David, great article and I’m looking forward to the next. Could you possibly clear something up for me? This is probably false thinking but I always thought there was some sort of cycle life a lithium ion battery has, like after approximately 1000 or 2000 clicks on the charger things would start to degrade.. my thinking is that if you charge them always at 50% then you are just gonna reach that charge cycle limit sooner.
Also is there truly no memory effect if you never let the battery run down?