In the world of airsoft one of the most common questions we receive here at Airgun Depot is, “How long do I charge my battery for?” Each battery is different, so there really is no concrete set of rules that apply to charge time of a battery and how many shots you will get off before you battery starts to really die out and slow down your rate of fire until there is just not enough electric energy left to actually perform a complete shot.
We’ll start with the different kind of airsoft batteries that you may encounter out there in the world of Airsoft but we will stick mainly to the ones we offer so as to not confuse you. Some of you may have already noticed that airsoft batteries are notoriously similar to RC batteries. Well as a matter of fact they are the exact same thing!
Nickel Metal Hydride (Ni-Mh) are the most common airsoft battery out there and come stock with most packaged guns as well as the most common aftermarket purchased batteries. Compared to others they are the safest, deal with cold weather excellently as well as are much smaller than there Ni-Cad cousins. The draw backs to them are is they tend to discharge much faster when than any other when left standing, in high discharge applications it can’t reach its full potential and quick charges (1.5 amps+) and quick discharges can damage the battery. Overall they are the preferred battery of any airsoft play for sheer reliability and even when overcharged if correctly discharged can be brought back to life.
Nickel Cadmium (Ni-Cad) batteries are much like the Ni-Mh batteries except they will be bulkier, heavier and not deal with extreme temperatures as good. There upside is they are excellent for quick charging and discharging with almost no damage done to the cells and are even better for guns that will use a large draw of energy and high rates of fire. These are more of an experts battery and can easily be ruined if overcharged even once. If overcharged the battery cells can split, leak and even cause fire so they should never be left alone even with a smart charger.
Lithium Polymer (Li-Po) are the most expensive, yet the most advanced batteries currently on the market. Ranging in only two voltages 7.2v and 11.2v they are great for upgraded AEGs that will be able to take the blistering rate of fire that these batteries produce. Li-Po batteries are not effected by extreme temperatures as well as have the longest charge time compared to others. However, they are extremely dangerous and require special charges that can cost $60+. If overcharged they can explode and cause chemical burns, fires and even in some cases death. With a price tag of $75 for just the battery and that $60 charger your looking at an investment. Research your makes and brands of batteries before you purchase them because there is a lot of fraudulent sellers out there that pedal incorrectly rated batteries that can even be more dangerous than they already are.
Alkaline are the oldies, but goodies. You don’t usually see this in airsoft or RC cars much more these days because they can not take the stress that Ni-Cad and Ni-Mh batteries can or put out the same rate of fire. However though, Alkaline batteries can last years at room temperature (70F), even longer if in a colder environment before loosing even a sliver of a charge and are very cheap. Due to there chemical property though, they really do not like to recharged numerous times and can not take the high voltage pull that some of these guns take. To top it off they can not have as much milliamps as the other three so you would be looking at a considerable less shooting time. These are rare to
see but some people do make there own batteries.
Here at Airgun Depot though we recommend sticking with Ni-Mh batteries for any application that calls for long duration with normal amperage loads and Ni-Cad for short situations with high amperage loads. We do not sell Li-Po batteries sadly because of there danger rating and cost to our customers.
Now that you have a better feel for each type of battery lets get into how long you should charge your battery for! We recommend using a smart charger if you can afford one, it takes a lot of hassle and danger out charging batteries and makes it so you don’t have to coddle and baby your batteries. If you can’t afford one though we do have a few tricks of the trade to help you find out if your battery is full charged and how long you should charge it.
The first step to make sure your battery is being charged correctly is that the converter is plugged directly into the wall, don’t use an extension cord or a power strip if you can help it. This can increase the charge time of your battery as well as if your power strip does not have a built in surge protector and when you have a lot of devices plugged into it and you get hit with a surge it can damage the battery. With a power strip you also have to worry about the power being split evenly into each device as well. Plugging it into the wall is the safest way to charge your battery and the way we recommend.
How long you should charge your battery is totally dependant upon how many milliamps or mA it has. If it has 1400mA it will charge much faster than a battery with 2800mA. Now look at your converter, you will notice several things on the sticker that will be affixed to it. We are looking for the output rating on it specifically. It usually says something like “OUTPUT: DC 8.4v 300mA” but changes from brand to brand and model to model. See that 300mA on the charge? That’s how many mA its charges per hour so if you have a 1500mA battery and a 300mA charger its just simple math from this point.
1500 / 300 = 5
So it will take 5 hours total to charge a completely dead/new battery to its full capacity. You simply divide the mA on the charge to the mA of your battery and you will get the time it should take to fully charge a completely drained battery. This does mean to set it and forget it though. In most cases your battery has already been charged once even if still new for quality control purposes so you really need to keep an eye on your battery still.
Trick of the Trade:
But how do you keep an eye on your battery and no its fully charged with a smart charge or a voltmeter on hand? Simple! You simply touch the battery from time to time with your hand to feel the temperature. If its warm, not luke warm, its fully charged! If it’s hot you may have damaged the battery, which is no good for you or the battery. You never want to leave your battery unattended. It’s like leaving the stove on and then going to see a movie, its just not safe.
Now this is a crude but effective way to check if your battery is charged but I never ever recommend relying on this %100 percent of the time. It’s not fool proof and even in some freak situations it may not work at all. If you plan on getting serious into airsoft a smart charger should be the first major investment and upgrade to your soon growing collection.