Note: I originally wrote this review to go on the website I purchased the battery from, so forgive me for reiterating basic airsoft information that could of been left out.
Link to battery: http://www.batteryspace.com/index.as...OD&ProdID=2905
When I purchased my JG Mp5 it came with a cheap Chinese made 8.4 volt 1200 mah battery that would last, at most, 1000 rounds, which was simply not enough for day long games. So I looked into buying a longer lasting battery. Many airsoft sites offer a wide selection of batteries, some having the exact same specs but a different name and price, making it very confusing for someone like me. After further research, I came to find that some batteries sold on these sites cannot hold a charge for very long, because of their bad quality. When I learned this I decided to avoid the overpriced batteries of airsoft sites. With a simple search, I found many sites, some advertising airsoft batteries, but none meeting my battery and price requirements, except for one, which I found after slowly moving through unorganized sites with conflicting information on batteries. On the front page of batteryspace was my answer; displayed in wonderful words 'Airsoft Batteries.' I immediately went to that section and found the highest capacity battery that suited my need, a 4200 Mah 8.4v Nimh battery. When comparing the specifications of my newly found battery to that of a similar battery found on an airsoft site, I was amazed at the price of Batteryspace’s battery. A similar battery would of cost me at least $60 dollars if I had bought it on another site. I looked around for reviews on other sites, and after finding none, I was a little weary of trying an un-reviewed product, but I went ahead and purchased it and no little that a week later I had the battery in my hands. My first thought was 'OH, this is a heavy battery!' When I pushed the battery in my full stock, I realized that the cells were much larger than lower capacity china batteries, but it still fit in the stock! (Which was not a problem because of the usually forgiving amount of room given in airsoft guns.) After charging for the appropriate amount of time, I plugged it into my gun and test fired. I was in for a surprise! The rate of fire (which in airsoft guns is increase by the voltage of the battery) was boosted 3 or 4 rounds per minute from the stock battery! Even with the same voltage, as I learned later because it had so much more capacity than the original battery, it pushed out energy even faster! Went I went to a game later that week, I now had superior rate of fire that amazed my friends. And even better, the battery has so much capacity that I have charged the battery fully, attended a game the next day, the another a week later, and then target shot for a month afterwards before have to charge the battery! I am amazing, and to this day I have recommended batteryspace to all my fellow airsofters.
Price is considerable lower than other batteries of it's class.
Amazing capacity! It lasts thousands of rounds and multiple games!
Great rate of fire compared to stock battery.
Durable wiring and shrink-wrap, made to last.
Thick gauge wiring, good for a low-resistance setup.
Better than average discharge rate.
It's a heavy battery! (Can be a pro for someone looking to balance their gun)
The cells are bigger than lower capacity cells (again not a problem for me, but someone with extremely tight space tolerances may have a problem)