aznriptide859 Posted May 10, 2015 Report Share Posted May 10, 2015 So I recently acquired a CA M249, and I'm looking for ways to fit a larger high-capacity lipo in the gun. The gun came with two full stocks, but I'm looking to switch to the stubby retractable stock used on the Mk46. Of course this eliminates my ability to use a large battery, so I'm stuck between two options: 1. Wiring the battery to the front under the handguard 2. Wiring the battery to the free space within the box mag I'm tempted towards #2, but it means swapping box mags is a bit more annoying. #1 is preferred, although the battery space is much more limited. Last option is to keep the full stock of course...but that thing's huge lol. How do you guys wire your 249's? Link to post Share on other sites
3vi1-D4n Posted May 10, 2015 Report Share Posted May 10, 2015 Front. The issue is that It can only hold an 11.1v 1500mah 25C and thats as big as it goes. You could get a battery box and increase the capacity to about 2100mah but thats about it. It depends how much you spam and your motor. I put an ok Torque up motor on it and on the 11.1v 1500mah at max we have fired 3000 rounds with no loss in ROF. But I can imagine most people fire a lot more from their LSW/SAW Link to post Share on other sites
aznriptide859 Posted May 10, 2015 Author Report Share Posted May 10, 2015 Front. The issue is that It can only hold an 11.1v 1500mah 25C and thats as big as it goes. You could get a battery box and increase the capacity to about 2100mah but thats about it. It depends how much you spam and your motor. I put an ok Torque up motor on it and on the 11.1v 1500mah at max we have fired 3000 rounds with no loss in ROF. But I can imagine most people fire a lot more from their LSW/SAW Unlike most of my other builds, I want to go for sustained fire, so I'm staying with 7.4v. But yea, after searching HobbyKing I couldn't find anything past 1800mah that would fit in that tiny space. Do you just remove your barrel when you want to swap batteries? Link to post Share on other sites
3vi1-D4n Posted May 10, 2015 Report Share Posted May 10, 2015 Yeah I have to remove the barrel for battery. Since this is shooting around 460fps I do have to run 11.1v for the ROF. Link to post Share on other sites
aznriptide859 Posted May 10, 2015 Author Report Share Posted May 10, 2015 Gotcha. Do you wire your box mag in-line with your main firing circuit as well? I'm still trying to figure out if I need a resistor in the circuit or not. Link to post Share on other sites
evansy Posted May 10, 2015 Report Share Posted May 10, 2015 I use one of these in the front of mine. http://www.componentshop.co.uk/7-4v-2200mah-35c-continuous-discharge-lipo-battery.html It's about as big as I can fit with the lower ris. Link to post Share on other sites
T3CH Posted May 10, 2015 Report Share Posted May 10, 2015 Gotcha. Do you wire your box mag in-line with your main firing circuit as well? I'm still trying to figure out if I need a resistor in the circuit or not. You could put one in I suppose, but if you're not planning on running anything above a 7.4v you probably wont need to. Mine is directly wired to the motor and has no problems running with a 9.9v LiFe. Link to post Share on other sites
3vi1-D4n Posted May 10, 2015 Report Share Posted May 10, 2015 I use an A&K sound activated boxmag so it autofeeds. On the CA mag I have always just used the button at the bottom. On the Mk43 I do wire the motor directly to battery, but I use a 10w resistor to limit the voltage. Link to post Share on other sites
ED-SKaR Posted May 10, 2015 Report Share Posted May 10, 2015 I wired and modded yet another lsw recently. The requirements was to cut a larger hole inside the boxmag so the user could poor BBs directly from a bottle into the attached magazine (IE, you don't remove the magazine to reload) With a silly large battery in the boxmag(4ah, 12v nimh)* she can pretty much fire forever. *not a lipo but we still used a mosfet to prevent the high voltage from melting the trigger contacts. The magazines motor was wired in series with the gearbox motor, it lowers ROF a tiny tiny bit and reduces battery life but it means you don't ever have to think about the magazine until it runs out of BBs. Link to post Share on other sites
Yoroiden Posted May 10, 2015 Report Share Posted May 10, 2015 I started copying this guy a few years ago: http://arniesairsoft.co.uk/forums/index.php?/topic/193724-boxmag-wiring/&do=findComment&comment=2422857 http://arniesairsoft.co.uk/forums/index.php?/topic/193724-boxmag-wiring/&do=findComment&comment=2422996 I've modded quite a few M249s, M60s, and a even a few PKMs with his diagram, and they all work just fine. I have found if you hack out the original 9v battery compartment, it opens up more space for some massive lipo batteries. I had no trouble fitting this inside: http://www.hobbyking.com/hobbyking/store/__21942__Turnigy_nano_tech_7600mah_2S_40_80C_Lipo_Pack_TRA2869_Summit_E_Revo_E_Maxx_.html I believe it is possible to fit even larger than that inside a modded M249 box. Link to post Share on other sites
aznriptide859 Posted May 10, 2015 Author Report Share Posted May 10, 2015 So it seems that the previous owner already wired his 249 for use of powering the box mag by the main circuit, but he's wired it in parallel rather than series. I guess it's for one box mag that will run off the main leads, and the other one that's push button only. Will this last on either a 7.4v or a 11.1v powered setup? Link to post Share on other sites
kojak Posted May 12, 2015 Report Share Posted May 12, 2015 I use the MAG 100rd style boxmag (modified to load from the top) with a collapsible stock, so front wiring is the only way. I've managed to fit a 2000maH 11.1v battery under the barrel, just barely. It isn't pretty, but if I think I'll be in a bad situation if the battery runs out I've ziptied a second lipo above the barrel: Link to post Share on other sites
Recommended Posts
Archived
This topic is now archived and is closed to further replies.