Battery
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Battery Types and Charging Information
Ni-Cad or NiCad (Nickel Cadium) Description
A single cell is 1.2volts, so if 7 2400mAh cells are made into a pack the result is 7 x 1.2 = 8.4 volts. This would be a large battery. Large batteries just mean they usually fit into full stock guns, e.g. M16 or MP5A4. Although some full stock guns can fit a 9.6 volt battery which would consist of 8 cells, or even 10.8volt batteries, which consist of 9 cells. Small batteries have the same layout as large batteries but on a smaller scale. The most you can get out a small NiCad cell is 600mAh, where as the most you can get out of a large NiCad cell is 2400mAh. NiCad's have a constant level of power and then very suddenly drop off and die. This means your gun has a constant rate of fire right up until the end. NiCad's have to be discharged fully after use to stop the formation of crystals, these crystals shorten the life of your battery. This is also know as when a battery develops a memory.
NiMH (Nickel Metal Hydride) Description
Nickel metal hydride cells typically have more capacity than NiCad's however this comes at a price. The most you can get out of a large NiMH cell is 4300mAh, although these are very rare and 3300 is more common, the most you'll get out of a small NiMH cell is 1400mAh. As I said more capacity does not mean a better battery, this penalty is that, unlike NiCad's, NiMH's slowly lose power until they finally die. This means after a while your guns rate of fire will slowly start to decrease until it becomes hopelessly slow. NiMH do not need to be discharged although it can still be done, for the user to know how long he needs to charge from. However, I’ve heard discharging a NiHM too much can cause damage to the battery. TM Dischargers do not totally discharge batteries for safety reasons.
NiCad Charging
If you have a Nickel Cadium battery you need to use the following equation:
Battery capacity x 1.4 / Charger Output
For example:
For a 600mAh small battery on a 250mah charger: 600 x 1.4 / 250 = 3.36 hours
For a 2400mAh large battery on a variable charger charging at 120: 2400 x 1.4 / 120 = 28 hours
NIMH Charging
Nickel Metal Hydride batteries are less charging efficient and use the following equation:
Battery capacity x 1.5 / Charger Output
For example:
For a 1050mAh small battery on a 250mah charger: 1050 x 1.5 / 250 = 6.3 hours
For a 3300mAh large battery on a variable charger charging at 120: 3300 x 1.5 / 120 = 41.25 hours
Originally posted by Demoncase
Battery Capacity
For every mAh of your fully charged and healthy battery you can expect to fire around 2 to 2.5 BBs.
So: mAh x 2 = rough lower amount of rounds per charge mAh x 2.5 = rough upper amount of rounds per charge
So: a 600mAh battery will allow you to fire between 1200 and 1500 rounds a 1000mAh battery will allow you to fire between 2000 and 2500 rounds a 1700mAh battery will allow you to fire between 3400 and 4250 rounds a 3000mAh battery will allow you to fire between 6000 and 7500 rounds
Assumptions
The above assumes your gun is a standard/ Stock TM AEG The above also assumes your battery is an 8.4V battery. The Above assumes you have correctly trickle charged your battery The above assumes you are shooting at above 8°C.
Variations
Upgraded guns and more powerful stock guns (CA, GnG etc) will draw more power, therefore an 8.4v battery will not last as long as the above. This is unknown variation due to the level of upgrade- as an example some users have found a CA m4 operating at 328fps to use a 600 mah 8.4v battery in less than 700 rounds. Others don't suffer as badly but typically you can reduce 25% from the amount of rounds you will shoot from the above calculations. Generally if your gun is operating at 328fps then go for a 9.6v or 10.8v battery to come back into line with the above calculation
The older a battery gets, the less effectively it delivers and receives charge. If you are getting less and less rounds before recharging then consider renewing your battery.
Likewise 'fast' charging freqeuntly 'ages' your battery, resulting in the holding of less charge.
Colder conditions, below 8°C in particular, play havoc with the batteries we use: particularly the smaller packs. It's typical to have to knock 15 to 20% off your expected upper round limit per charge.
Firing Full auto is also bad for battery life: Short controlled bursts gives better amount of rounds per charge.
Charge dissapates over time: you can expect to lose between 5-10% off the rough upper round limit for every day since you charged it.
Caveats
This is a very rough guide indeed- if you take into the account the weather, a worn battery, charging 3 days in advance and a couple of minor upgrades you can't predict whether a 600mah will give you 900 rounds or 1500 rounds.
So how many batteries will I need?
Most of the noobs with hireguns at the site I go to shoot between 1500 and 3500 rounds in a single day.
So if you have your own gun you'll need 2-3 600mah minipacks/ sticks or a 1700mah, dependant upon which gun it is.
Note: Trying to connect 2 or more batteries in parallel or in series is a very bad idea.
Buy one with a higher voltage to make your AEG fire faster or one with a larger capacity to make it fire for longer between charges.
