I have almost a dozen mods and a few dozen married battery sets but only a few get used regularly, the others just sit in my regulated mods until it's time to use them. Is this a good way to keep them? Would it be better to take them out of the mods? Leave them on chargers? Swap them into regular rotation on occasion?
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What's the best way to keep batteries in good condition?
- Thread starter urs1ne
- Start date
If you got 'em use 'em.
No battery improves with age. The projections for shelf life of lithium chemistry batteries is about 3 years before they start to deteriorate just by aging out. Mind you that loss of capacity is a slow process, but they don't remain "shelf stable" by just sitting there unused either.
Don't put them in the 'fridge and especially not the freezer. Longer life spans can be achieved by storing them at consistent room temperature. Extremes of cold or heat only makes things worse. Freezing can physically damage the batteries.
3.7 volts is the typically recommended voltage to keep them at for long term storage. Don't store them long term in a depleted state.
One of the worst things you can do to prematurely shorten the life span is to drain them too low. Although almost all IMR chemistry batteries can be safely drained as low as 2.5 volts, dropping them that low repeatedly will shorten their overall life span.
Don't keep them parked on a charger. Practically all lithium chargers still pass a small amount of current through the battery after the charge cycle is complete. (Some chargers are a lot worse at this than others.) Depending on how good - or bad - the charger is that could put the batteries over voltage if left in the charger in a matter of several hours to several days. So - just don't do that. Take 'em off the charger when the charge cycle is done.
http://batteryuniversity.com/
No battery improves with age. The projections for shelf life of lithium chemistry batteries is about 3 years before they start to deteriorate just by aging out. Mind you that loss of capacity is a slow process, but they don't remain "shelf stable" by just sitting there unused either.
Don't put them in the 'fridge and especially not the freezer. Longer life spans can be achieved by storing them at consistent room temperature. Extremes of cold or heat only makes things worse. Freezing can physically damage the batteries.
3.7 volts is the typically recommended voltage to keep them at for long term storage. Don't store them long term in a depleted state.
One of the worst things you can do to prematurely shorten the life span is to drain them too low. Although almost all IMR chemistry batteries can be safely drained as low as 2.5 volts, dropping them that low repeatedly will shorten their overall life span.
Don't keep them parked on a charger. Practically all lithium chargers still pass a small amount of current through the battery after the charge cycle is complete. (Some chargers are a lot worse at this than others.) Depending on how good - or bad - the charger is that could put the batteries over voltage if left in the charger in a matter of several hours to several days. So - just don't do that. Take 'em off the charger when the charge cycle is done.
http://batteryuniversity.com/
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From batteryuniversity.com:
BU-702: How to Store Batteries
Learn about storage temperatures and state-of-charge conditions.
The recommended storage temperature for most batteries is 15°C (59°F); the extreme allowable temperature is –40°C to 50°C (–40°C to 122°F) for most chemistries. While lead acid must always be kept at full charge during storage, nickel- and lithium-based chemistries should be stored at around a 40 percent state-of-charge (SoC). This minimizes age-related capacity loss while keeping the battery operational and allowing for some self-discharge.
3.7V does not equal 40%
Edit: SoC includes capacity, as well as voltage, so 3.7V is indeed the correct storage state. My apologies.
BU-702: How to Store Batteries
Learn about storage temperatures and state-of-charge conditions.
The recommended storage temperature for most batteries is 15°C (59°F); the extreme allowable temperature is –40°C to 50°C (–40°C to 122°F) for most chemistries. While lead acid must always be kept at full charge during storage, nickel- and lithium-based chemistries should be stored at around a 40 percent state-of-charge (SoC). This minimizes age-related capacity loss while keeping the battery operational and allowing for some self-discharge.
3.7V does not equal 40%
Edit: SoC includes capacity, as well as voltage, so 3.7V is indeed the correct storage state. My apologies.
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But manufacturing shipping charges are between 3.5 to 3.7v, not really recommended to keep a battery below 3.0v for long periods of time though they can be discharged down lowest at 2.5v, it is not really ideal to store them at that low a voltage as they sit they discharge very very slowly, go below 2.5 for to long, the anode and cathode break down, moment you recharge them the copper is diluted out into the electrolyte and you risk micro-arching internally from there on.
State of Charge (SOC) is an impractical thing for home users to actually measure. It is not equivalent to a simple voltage percentage. If you actually read the chart further down on the page referenced you would see battery university referencing a battery voltage of 3.82 volts as indicative of a lithium cobalt battery at 40% SOC. Your suggested storage voltage of 2.8 volts is pushing them too close to the discharge point where internal breakdown occurs.
In usage:
Don't reach or pass the batteries CDR.
Don't over drain or over charge the batteries.
Charge the batteries in an external charger.
Let the batteries rest for 10-15 min before charging and discharging them.
In storage:
Remove the batteries from the mod.
Keep them at nominal voltage.
Keep batteries at moderate temp.
Don't reach or pass the batteries CDR.
Don't over drain or over charge the batteries.
Charge the batteries in an external charger.
Let the batteries rest for 10-15 min before charging and discharging them.
In storage:
Remove the batteries from the mod.
Keep them at nominal voltage.
Keep batteries at moderate temp.
OP can just read the page for himself, here:
http://batteryuniversity.com/learn/article/how_to_store_batteries
I see that nominal voltage is the recommended storage charge. If I ever need to store any, that's what I'll be using. Throwing in the "SoC" crap was unnecessary and confusing. Glad I learned something today.
http://batteryuniversity.com/learn/article/how_to_store_batteries
I see that nominal voltage is the recommended storage charge. If I ever need to store any, that's what I'll be using. Throwing in the "SoC" crap was unnecessary and confusing. Glad I learned something today.
For very long term storage, you should check the battery voltage from time to time and charge back to nominal, since batteries loose their charge over time, even when not in use.
If a battery ever goes below 2V the best thing to do is to toss it, since it can dead short when charged again.
If a battery ever goes below 2V the best thing to do is to toss it, since it can dead short when charged again.
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Unbalanced mod charging is bad for battery life in two ways:
1. It can over charge one of the batteries above 4.2V
2. If both batteries don't have the same charge, then the battery with lower charge is going to be stressed more.
1. It can over charge one of the batteries above 4.2V
2. If both batteries don't have the same charge, then the battery with lower charge is going to be stressed more.
In a regulated mod, the lower the charge the higher the current which means the batteries are stressed more, so not letting batteries go completely empty (3.2V+-) before charging with lengthen their life.
The higher the charge current the shorter the battery life, so it's better to charge at 0.5A or 1A and not 2A unless you're in a hurry.
The higher the charge current the shorter the battery life, so it's better to charge at 0.5A or 1A and not 2A unless you're in a hurry.
With all that said you don't have to handle batteries with silk gloves just to get a few extra weeks out of.
Find a compromise between battery life and convenience that you can live with.
Batteries are cheap so when you feel they have lost capacity and it's time, just toss and replace them.
Find a compromise between battery life and convenience that you can live with.
Batteries are cheap so when you feel they have lost capacity and it's time, just toss and replace them.
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