Lithium batteries power many of our everyday devices. But like any battery, lithium batteries degrade over time and use. And a failing lithium battery can cause device performance issues or even become a safety risk if left unchecked. So how do you know when it’s time to replace your lithium battery? As a professional lithium battery packs manufacturer, I will share what to look for.
Signs Your Lithium Battery Is Failing
The first signs of lithium battery failure often show up during daily use of your device. Be on the lookout for these common red flags:
Longer Charging Times
If your lithium-powered device is taking significantly longer to charge, it likely indicates the battery is wearing out. Healthy lithium batteries should charge in about the same time they always have.
Gradually increasing charge times points to diminished battery capacity and efficiency. And that downward trend will continue as the battery further degrades. Prolonged charging compared to when the battery was newer is an early clue a replacement is around the corner.
Greatly Reduced Battery Life
Another everyday symptom of a struggling lithium battery is greatly reduced runtime once fully charged. For example, if your smartphone’s battery life has dropped from 18 hours to just 8 hours, it means the battery isn’t holding nearly as much juice as it could when newer.
Rapid discharge of a fully charged battery often correlates with high internal resistance preventing the stored energy from being utilized. Shortened runtime is a clear indicator a lithium battery is wearing thin.
Loss of Runtime Consistency
While batteries lose overall capacity as they age, runtime is typically consistent at various charge levels if the battery remains healthy.
For instance, you may estimate a runtime of 90 minutes when your smartphone battery is at 50%. If that expected 90 minutes suddenly drops to 40 minutes at the same 50% charge, it likely signals impending lithium battery failure.
Inconsistency in projected runtime points to battery issues preventing proper energy output as charge decreases.
Device Function Problems
If you begin experiencing device performance problems like lagging, freezing, forced restarts or sudden shutdowns, the root cause may be a failing lithium battery.
As battery health declines, voltage inconsistencies and maximum current issues can develop. Those battery defects can negatively impact overall device functionality.
So while bugs or outdated software can also cause glitches, think about testing the battery if your gadget starts acting up out of the blue.
Not Powering On
Once a rechargeable lithium battery reaches the end of its useful existence, a complete inability to power on your device is common.
If your device won’t start up at all even after an overnight charge, it’s very likely the battery has called it quits. No signs of life even after lengthy charging suggests your lithium power source has completely stopped working.
Testing Lithium Battery Health
Catching failing battery symptoms during everyday device use is handy. However, you can also use diagnostic testing to gain more definitive insight on your lithium battery’s current state of health.
Let’s look at some DIY ways to quantitatively assess whether or not it’s time to swap out an aging lithium battery.
Check Initial Voltage
Using a voltmeter, you can measure your lithium battery’s output and determine if it’s gone bad. This method works well for assessing the overall health of rechargeable multi-cell battery packs.
Start by fully charging your battery. Then connect your voltmeter leads across the positive and negative terminals to take a reading. Compare your voltage measurement to the battery’s rated level.
Significant deviation lower than optimal voltage strongly suggests degradation or failure. For example, a flagged 3.4-3.6V reading from a lithium pack rated for 3.7V.
Analyze Discharge Curve
You can also plot a lithium battery’s voltage discharge curve using a voltmeter. This tests power output over time and helps identify faulty batteries.
After fully charging, connect your battery to the voltmeter. Add a small current load comparable to typical device usage levels. Track and record voltage decreases over several hours until fully depleted.
Plot voltage against time. A failing lithium battery will show inconsistencies like overly rapid drops or irregular discharge slopes versus a healthy battery’s gradual downward curvature.
Reviewing discharge curves can diagnose issues like high internal resistance or dropping capacity.
Perform Capacity Testing
Capacity represents a lithium battery’s maximum energy storage potential. And batteries lose overall capacity as they degrade.
Using specialized battery testing equipment, you can quantitatively determine your battery’s total current capacity compared to its original rating. Capacity retention actually defines state of health.
Capacity testing first fully charges the battery. Then controlled discharge testing follows while measuring current over time until the battery is empty. Current and time data translates to capacity.
Batteries retaining 80% or less of their new capacity exhibit markedly reduced performance and imminent failure risk.
Extending Lithium Battery Lifespan
You can’t prevent lithium battery failure forever. But you can take steps to slow the inevitable capacity loss through proper use and care. Here are 5 lithium battery longevity tips:
1. Avoid Hot Environments
Exposing lithium batteries to high ambient heat degrades performance and shortens overall lifespan. For longer viability, keep lithium powered devices away from heat as much as possible.
Ideally, try not to use or apply charging in hot conditions exceeding 90°F whenever you can avoid it. And absolutely never leave devices with lithium batteries inside hot cars or direct sunlight.
2. Stay Between 20%-80% Charge
Fully charging lithium batteries actually adds stress, accelerating aging effects. Instead allow your device flexibility to cycle between around 20% to 80% charged during everyday use rather than constantly keeping it fully topped off.
The 20-80% buffer avoids both minimal charge and full charge extremes to minimize battery wear over time. Just plug in your device whenever convenient to stay within that approximate state of charge window.
3. Use a Charger Made Specifically For Your Device
Avoid cheap chargers that aren’t specifically designed for your make and model device. Cut-rate charging accessories often apply higher uncontrolled voltages stressing batteries.
Pay a little extra for an OEM smart charger that optimizes voltage and current to properly charge your device’s lithium battery. Proper charging goes a long way towards battery longevity.
4. Don’t Let Batteries Fully Discharge
Allowing lithium batteries to drop below around 20% charge on a regular basis strains battery health. Never fully discharging down to zero if avoidable is far better for longevity.
As with overcharging, deep discharges accelerate aging effects leading to earlier failure. Always recharge well before batteries empty completely whenever possible.
5. Store Properly When Not In Use
During prolonged device inactivity, be sure to store lithium batteries properly. Keep batteries around 40% state of charge rather than fully charged or discharged. Remove batteries from devices and allow open-circuit rest if the inactive duration exceeds a few weeks.
And remember to keep batteries out of temperature extremes during storage. Cool, dry locations are ideal for maintaining battery health when not used regularly. Proper ongoing storage preserves overall lifespan.
When To Replace Lithium Batteries
If you notice any of the end-of-life symptoms described earlier, it’s probably time to replace your lithium battery:
- Charging takes significantly longer
- Greatly reduced runtime per charge
- Inconsistent remaining runtime projections
- Performance issues like lagging or restarting
- Fails to power device on when charged
Battery testing can also confirm replacement need if your lithium battery shows:
- Depleted initial voltage
- Discharge profiles deviating from normal
- Total capacity at or under 80% rating
Swapping out fading lithium batteries restores device performance and usability. And replacing them before complete failure provides you reliable service moving forward.
