Bite The Bullet
Fuse Removal - Does it matter? (2005-12-30)What is the fuse for?
Tokyo Marui and several other manufacturers include a small 15A fuse in their guns to protect the motor and other electrical components from electrical surges. The fuse is set to a low amperage level such that there is a large safety margin. Once the fuse blows, all electricity to the motor and trigger assembly will cut off, and the gun will no longer fire.
How often do these electrical surges occur?
These surges certainly do not occur often, and in our experience only occur in very rare situations and happen in less than 0.1% of the guns we sell. There are many reasons that such a surge could occur, including:
- If you install a high voltage or high amperage battery in your gun, then the amount of electricity it generates could blow the fuse immediately.
- Other times, your gearbox may jam and the operator may keep his finger on the trigger in a futile attempt to "unjam" the gears. This may also cause a power surge.
- Using cheap knockoff batteries may cause sudden power surges
What will happen if I do not have a fuse and such a power surge occurs?
Power surges are not good for the AEG motor and trigger assembly. Short periods of power surges won't cause any major damage to your gun and it will indeed keep running after the surge subsides. Pro-longed power surges will cause the motor brushes to wear out much faster, or melt your gearbox electrical wiring. But pro-longed power surges are a result of the following:
- You are using a battery with way too much voltage and amperage
- Your gearbox jams and you keep your finger on the trigger for more than 5 seconds in a futile attempt to unjam it. The motor will get very hot and you should be able to feel it through the grip.
Why then would I need to remove the fuse?
Clearly the fuse has its benefits, but removal of the fuse is necessary in some upgrades due to the following reasons:
- A high power upgrade requires a very high powered battery which exceeds the fuse's tolerance. However the battery does not exceed the motor's maximum tolerance, so the fuse then becomes a liability and inhibitor more than a protector. (or course installing a higher Amperage fuse would be acceptable)
- Installing custom internal batteries in tight foregrips and stocks, where the battery would not have enough room to fit unless the fuse is removed.
Can't I find a way to keep the fuse and run my high power upgrade, and keep the battery stored internally?
Unfortunately on some guns, you simply "can't have your cake and eat it too". If you opt to upgrade your gun, then you basically need to accept the fact that you are altering the specifications of the gun to outside of the factory's original intended configuration. Doing so will reduce the longevity and reliability of the parts within the gun. If you upgrade to 400fps, then you'll simply have to accept that you need to run a much large battery with higher voltage. With or without a fuse, this higher voltage is going to wear the motor brushes and internal circuitry down much faster than in a normal stock gun.
Then what is the optimal configuration that keeps my gun running for the longest time?
On Marui guns, Tokyo Marui had designed its circuitry around 7.2v 600mah and 8.4v 1200mah batteries as standard. Unfortunately these low powered batteries deliver such low performance that most people find it unacceptable. As a result, people tend to run 8.4, 9.6v, or even 12v batteries to achieve a higher rate of fire, or to drive hard hitting upgrades. Again, moving up to beyond the standard batteries will immediately start to wear down your gun's motor and electrical circuitry. If you want longevity, then stick with a 7.2v or 8.4v battery. But understand that these batteries are incapable of driving any kind of upgrade.
I want to upgrade my gun and keep my fuse!
We cater to this but in many instances, that means you will need to carry your battery externally in a battery bag. Keeping the fuse box in many cases will take up too much space in the grips, and therefore you will not be able to fit your entire custom battery inside the gun. Again, this is a tradeoff that you must decide upon. Our recommendation is to simply remove the fuse and store the battery internally. Our historical data shows that only a very small percentage of upgraded guns will suffer a major motor malfunction due to the fuse removal. Our own technicians feel that this risk is worth taking for most people who want high power upgrades that still look good.
Does keeping the fuse make my gun "live" longer
Again, the fuse only protects the gun against sudden electrical surges that might burn out the motor faster. But in an upgraded gun where a fuse removal is necessary, this is probably the least of your worries. In an upgraded gun, the gears, pistons, cylinder, nozzle, etc all tend to wear out much faster than the motor. You may need to go through several changes of gears and other gearbox components before your motor starts showing signs of requiring change. Again, this is just the tradeoff you must accept whenever you upgrade guns. You simply cannot expect to upgrade a gun and have it run as durably and reliably as a stock gun. Guns are like cars. If you upgrade them, then expect to change out parts more frequently from accelerated wear-and-tear!
We hope this article clears the air a bit on the topic of fuses.