A quick Question

[TommyGunner]

Okay my friend accidentally bought a large style 8.4V 1800mah battery for his MP-5 but didn't realize that is was too big

So he said he would sell it to me for what he paid $15. Now it is an 8.4V 1800mah battery but it is made by UTG (not known for there quality) Would it be unwise to use this battery as a backup for my Thompson or for people who's batteries go dead during an WW2AA event here?

Oh and dont worry since this post is so small Il delete it when my questions is answered to save bandwith.

TommyGunner

[Nimlas]

Sure you can use it!
A battery is a battery!

[TommyGunner]

Thats what I figured, but I thought Id play it safe and ask. So the Thompson can take an 1800mah battery? Awsome I thought the limit was a 1700mah, but I guess I was wrong.

TommyGunner

[Nimlas]

tommygunner said:

Thats what I figured, but I thought Id play it safe and ask. So the Thompson can take an 1800mah battery? Awsome I thought the limit was a 1700mah, but I guess I was wrong.

TommyGunner

I sure hope the limit isn't 1700mah, I've got an 1800mah battery and it runs just fine. I used a nine volt in there once and it worked fine.

[2nd Bat]

The mah rating is simply the amount of juice the battery is capable of storing. The higher the Mah rating the longer lasting the battery will be. Think of it as a larger fuel tank. It won't change your horsepower (Your batteries volt rating) but you can go farther on a tank of gas.

It'll make a perfectly adequate back up or loaner battery. One cautionary note is that a battery drains at a tiny trickle rate as it sets around so it's always a good idea to drain it virtually all the way down and then charge it just prior to your event (maybe the day before or so) That way if it's been months since you used it you won't be surprised that it doesn't have much of charge left. Incidently if its a Nihm battery draining it prior to giving it a full charge isn't neccessary as the Nihm batteries don't have the memory that Nicads seem to have.

[TommyGunner]

Hmmm......Now how would you go about draining it, they do sell battery drainers right?

Also since the subject is battery, I want to bring my Thompson to a more realistic rate of fire. I think with an 8.4v battery the rate of fire is far too high, maby something in the 7volt range perhaps, What do you guys think?

TommyGunner

[2nd Bat]

Battery drainers are quite cheap and a good investment. They typically are under $10.00 and consist of a clip so you can hook them up to your battery. They contain a light that draws power and you know the battery is sufficiently drained when the light goes out.

I agree that an 8.4 in a Thompson gives too high of a rate of fire so I use a 7.2 volt in my thompson. It gioves more of a thump thump thump that seems about right. I bought the batteries at Radio Shack and they were 3000 mah NiHm batteries. They were a bit wider and shorter then the typical 8.4s so I had to file the inner liner inside the stock a bit to get them to fit. I have been quite pleased with the batteries and use them in my AK-47s as well since their rate of fire seemed too high as well.

I think the lower voltage is easier on the gun although you can go too low in charge and cause the gun to lug a bit which is also hard on the motor as well. The 7.2 works fine in my un modified stock Thompsons and AKs.

[schmitty]

7.2volts should work fine but it may cause your gun to stop functioning before the battery is really dead. Especially with Nimh batteries because their voltage is slightly lower per cell than Ni-cads. TM airsoft AEG's are designed to run on 8.4Volts (7 cells). As a battery is drained its voltage drops gradually, depending on the exact gun and spring etc. at some point the voltage will become to low for the motor to cycle the gears and spring anymore. If you start out with 7.2v this will happen sooner even though the battery may still have plenty of juice (Mah or amperage)left in it. The larger the battery (in MAH) the less of a problem this will be because it will take much longer for the voltage to drop.

Spending a little more for a decent charger with a built in discharger (cycler) would be a wise move if you intend to stay in this sport for very long.

Nimh batteries also posses the so called "memory" effect that nicads are known for, it just isn't as pronounced therefore they don't require cycling or discharging as frequently.

Schmitty

[2nd Bat]

Great points Schmitty. With the 3000 mah capacity and the less rounds fired nature of Mil Sim events I've never had one of the Radio Shack batteries run out during an event. The heads up is a good one so obviously if you're going to run with a smaller volt battery then the design tolerances be sure it has a lot of Mahs and it's fully charged before you head out.

Incidently the Thompson had a pretty healthy ROF (especially the 1928) so actually an 8.4 isn't all that out of whack.

[29ththerealpimps]

I use a 7.2 and an 8.4 and both work fine. I really can't tell the difference.

[schmitty]

Is the 7.2 a nicad and the 8.4 a nimh?

Schmitty