How To Charge And Store Airsoft Battery (With Safety Tips)

Batteries are extremely important in airsoft and sometimes they can make or break an AEG. As a matter of fact, batteries are amongst the first upgrades a player should think of when it comes to upgrading their airsoft gun, and knowing how to properly maintain them is of huge importance.

If this is your first time dealing with airsoft batteries you should know the fundamental rules when it comes to safety charging and how not to break one.

Batteries are sensitive, so whatever you do with them, do not rush them!

In short, you should know your battery type and research best practices for it, and use the right type of charger. I’ll be mostly talking about the best and most popular batteries used in airsoft, LiPo, and NiMH (you can read more on differences by following the link).

How long should you charge the battery?

To fully charge an airsoft battery you will need to divide the battery’s mAh (Milliam hours) with the charger’s mA (Miliams per hour) and charge it for that long.

BatterymAhCharger’s mACharging time in hours
NiMH 9.6 V20005004.8
NiMH 8.4 V 420050010.08
LiPo 7.4 V320010003.84
LiPo 11.1 V520010006.24
Refer to this table as an example

It might seem important to mention an average electricity efficiency loss which is usually between 10%-20%, so it may seem that it is better to charge the battery for a bit longer due to this reason (up to 20 minutes), however in practice the battery is rarely going to be so critically low that it is fully empty, so this should not be of a concern anyways.

However, if you ever charge it for a bit longer be careful if you see that the battery and charger are getting warmer than usual quit charging. None of this is a concern with smart chargers because they let you know exactly when the battery is fully charged.

If something is wrong with the charger or the battery, the efficiency loss may be ever greater above 40% and in which case you should consider either fixing the charger or getting a new one, or buying a new battery.

How to know when the battery is charged?

To know whether the battery is fully charged you will either have to guess based on the usual time that a battery takes to charge from the bottom to the top or simply use a smart charger that will indicate when the battery is full by switching from the red light to the green light.

This is the reason why in my opinion everyone should have a smart charger nowadays, they are not that expensive and they are really useful.

Without a smart charger, it is difficult to exactly say when the battery is fully charged because you do not know how much energy was still left when you took the battery out and started to charge it.

When you shoot from AEG and notice that it is slowing down, you can guess that the battery is getting low, so in theory, when you would continue to use it would eventually produce less and less energy until it would be completely discharged.

However, in practice no one does it and it would be counter-productive, so your best bet is to calculate that the battery is not completely discharged and is rather at 10%+ of total capacity.

So, you do not have to charge it for the exact time, but you can take it off a bit sooner because even if the battery is charged to 80% it will still work, just a bit less than usual if it were full.

What happens if you overcharge the battery?

If you leave a battery in the charger for an extended period after the battery was completely charged it may overheat the battery, destroy it and in some instances cause a fire and the leak of toxic chemicals.

However, this is only a thing with old charger types that continue to charge after the battery is fully charged.

Smart chargers do not have this issue because they can spot when the battery is full and they won’t continue to charge it.

It is also important to take into the equation what type of battery you use, some batteries (usually old battery designs) are more vulnerable and toxic, while modern battery designs such as modern LiPo would not cause much damage even if they broke.

In short, every battery no matter how modern the design may be is dangerous if it breaks, and it is just a matter of how serious the things may get or in other words, more or less of a leak and fire.

In case the battery starts to malfunction you should immediately throw it into the designated trash (avoid throwing them into the regular trash).

Tips for proper charging of a battery

Do not charge it if:

  1. The battery barely charges (It means that either the charger or the battery malfunctions and it is not smart to continue to use the charger or the battery in such a state. Usually, when a battery shows a sign of malfunctioning it’s usually good to forget about it and throw it because it can become dangerous, however, if the charger malfunctions it is possible to repair it.)
  2. The battery has a crack, looks bloated or it changed the color noticeably (it can easily start to leak and catch fire even outside of a charger, but especially within the charger)
  3. The charger does not match the battery type (Never attempt to charge a LiPo battery with a regular charger you would use for NiMh or some other battery, it won’t charge it properly at all and may cause a leak or explosion!)

Should I charge my airsoft battery overnight?

Charging a battery overnight or leaving a charging battery without supervision with a standard charger is never a smart decision because the battery can overcharge and get seriously damaged, while in some cases it can even catch fire.

However, If you own a smart charger you can feel comfortable leaving a battery charged because the battery will neither undercharge nor overcharge and it will be safe to leave it in an active charger for an extended period of time in most cases.

Yet, what I have learned is that it is not recommended to leave any technology in the electric supply without supervision for long periods of time because everything can malfunction no matter how extremely low the odds may seem.

This is especially concerning when it gets stormy outside and it is how many people I know, including my father lost precious technology such as PCs and speakers.

Electricity is a dangerous matter and sometimes the best safety, anti-thunder technology becomes useless when the static electricity levels get charged in the earth in case the lighting has crushed somewhere nearby.

Do airsoft batteries lose charge over time?

Every battery will lose its charge over time, so it is not smart to charge a battery and leave it for the next month thinking it will work as intended.

Some batteries lose charge after a week and some will lose the same amount only after a month or so, you can further check your battery model and see what the instructions say.

Do airsoft batteries come charged?

Some traders might charge the batteries before they sell them, however, the practice with manufacturers is that they almost never charge the battery more than it is required for the battery to stay healthy while in storage which is usually around 30% when they arrive at your place.

Therefore, you should always charge the battery fully when you get it for the first time prior to using it.

How to store airsoft batteries

Not all batteries are the same, but usually, every battery likes to be used at least from time to time so it doesn’t turn bad.

If you leave the battery in storage without touching it and recharging it for a few months, you can expect that such practice may compromise its efficiency and effectiveness, so try to use it at least once in a while, just like you should take care of your other airsoft gear.

Maintenance is extremely important in airsoft, so pay attention to it.

A few more tips that will prolong your battery lifespan are:

  1. Keep the battery in a secured bag ( You can use any bag such as zip locks, but for LiPo batteries, it is recommended to store them in a LiPo bag that is fireproof. They are extremely affordable and important for maintenance.)
  2. Store them under stable temperature (The temperature should never be lower than -20
  3. Keep the storage dry (any exposure to moisture can break the battery seriously)
  4. Do not mix the storage where you hold the battery with other metal objects
  5. Always charge batteries at least to 70% before storing them for a long time, LiPo should never reach critical 0% in storage while other battery types such as Nickel-based ones may get away with it but will still enjoy being maintained at least above 30%

Can you leave a battery in an airsoft gun?

You can leave the most batteries in your airsoft gun without any issues as long you take care of your battery by not leaving them completely empty for an extended period of time (usually for more than a few weeks).

If you charge your battery and leave it within your airsoft gun it will remain safe just as it would outside of it.

However, LiPo batteries are more sensitive, so while you could get away for longer than a few weeks with other batteries, I would at least unplug the LiPo in order to prevent the discharging.

You do not want a LiPo to get fully discharged and stay that way because it may destroy it.

We could additionally find the argument that if somehow the battery gets damaged and starts to leak it could additionally compromise the gun as well, but batteries do not randomly break out of nowhere, so just pay attention that your battery is healthy before placing it in your gun anyways and pay additional attention to it if it’s a LiPo.

Types of chargers you can use

Standard charger

Standard chargers are the most common chargers and due to different models, some are better and some are worse. We could say that a decent standard charger should be at least able to spot overheating and prevent it, but there are many standard chargers that do not have this ability.

Standard chargers work perfectly fine for their purpose, but they are not made for any kind of calibration, so they work plain stupid, charge for a programmed period of time, and shut down without giving you any helpful insights into charging levels.

As you can see, standard chargers will require from you some guessing and understanding of what battery type you own to optimize its charging time, so it does not end up undercharged or overcharged.

Smart Charger

Smart charges are here to save the day, they fix the disadvantages of standard charges at cost of the increased price.

They are more expensive than standard chargers but with a smart charger, you will always be at peace feeling safe.

A smart charger will give you insights into charging levels and will always calibrate the battery charge to its full potential.

In other words, if your battery was at 30% when you placed it into the charger, the smart charger will know that it needs to charge at only 70% for the battery to be full.

Whether it’s 10 minutes in case the battery was almost full and just needed s small energy support to get full or it is an hour, smart chargers will always finish the job at the right time and give you a green light as a sign that everything went as planned!

If you leave the charger in the electricity supply, it won’t overheat or destroy the battery either.

LiPo charger

Due to a specific LiPo technology that differentiates it from other batteries, LiPo batteries require a charger that comes with the ability to balance.

LiPo battery needs to be equally charged within each cell, so it does not malfunction when it comes to discharging.

A LiPo battery is amazing and it’s my choice every day, but it can not be recharged with any charger, so you must always check out that your charger supports LiPo batteries!

Best chargers (Recommended)

Here are two smart chargers I can recommend which will work great for NimH and LiPo batteries.

Tenergy Balance LiPo Charger

Tenergy LiPo charger works for all LiPo batteries and you shouldn’t use it for any other type of battery. It will fully charge 11.1 v LiPo in 2 hours, has a LED signal to show you the energy levels in a battery so you know when it’s complete and it’s made to prevent overcharging and possible accidents. It also comes with the LiPo protection bag you should use for safely storing the battery.

Warranty of 12 months and the affordable price for the quality it brings makes this among the best balance LiPo chargers on the market.

NiMH Smart Charger Ocean Loong

This NiMH smart charger is compatible with both, the mini and standard size tamiya connectors and will fully charge any NiMH battery starting from 8.4V to 9.6 V in less than 2 hours.

The protection feature automatically stops the charging after 6 hours to prevent overheating and damage in case you forget about it.

This charger is super simple to use, shows the green light during charging and looks just like your phone charger, nothing fancy but works perfectly, has safety features and doesn’t cost much.


Dino is a thrill seeker who loves to share what he learns about his favorite hobbies.

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