Increase battery voltage with additional cells idea. Will this work?

[Shepsy]

Hi there

 

I've been thinking about ways I can increase the voltage in my guns that use NiHM batteries.

 

The problem

 

I've found that battery size and shape and the space in side AEG's is a frustrating issue, and I dislike external solutions like battery pouches and PEQ boxes. I also like guns that are small and agile, like my MP5k with folding stock, but they don't give a lot of room for nihm batteries with lots of cells for greater voltage.

 

If we pretend LiPos don't exist for this post, I think I have some up with a cool solution to get more voltage into my AEGs while making the most of the space inside the gun.

 

Currently my MP5k has a 7 cell, 8.4v (total) stick battery in the top and I'm struggling to find 9.6v batteries that will be short enough to fit inside the 19cm space in the gun.

 

But, there is enough space in the hand-guard for an additional cell. This led me to the following idea (solution):

 

Solution(?)

 

If I create a little battery extension out of an additional cell of the same mAh and voltage, could I add it into the electrical system as shown in the attached diagram? I would be wired with Deans for less resistance between 'batteries'.

 

 

Question I don't know

Is there a limit to how many cells you could essential chain together if voltage isn't an issue?

 

If it does work, could you charge the single cell separately or charge it with the larger battery all connected together?

 

if this does work, does anyone make them? If not I find this quite surprising as it could be a great idea for getting that additional bit of power.

 

 

[Lozart]

Why not just use LiPo?

 

Yes, in theory what you have suggested will work. Whether it actually makes any real difference is up for discussion though depending on what your end game is.

[Sitting Duck]

It is kinda going backwards in the end

 

not being funny but yes it would work

though I'd make sure the cells are same type/capacity and if possible same make

would be a right bollock-ache to change n charge but all cells should be charged at same time

 

mp5k I would suggest:

 

http://www.hobbyking.com/hobbyking/store/uh_viewitem.asp?idProduct=84544

change motor to long shs torque

fit the mosfet up in handguard with hop unit

fit actual mini deans as these still offer less resistance than small tamiya - and are very compact connectors

fit the battery ar$e end first with thin alpha eco wire and wires should squeeze in ok with connector near rear of v3 box

 

This is the type of stuff I'm looking to do on my Galaxy mp5k (in bits coz keep looking at other stuff & mods)

& the poxy G5M mofo with ris that has to be removed every time to change battery

(the ris Galaxy mp5 is a REALLY crap design)

I haven't done it myself yet but that is what I'm looking at doing - jeez the mp5k's have crap battery space I know

 

Gun would seriously kick ar$e then

and at £5 a battery - why pi$$ball about with nimah's

[Shepsy]

Ah cool. Thanks for the info..

 

So based on the answers so far... yes it will work but its a pain in the arse!

 

@sitting duck... I installed an SHS torque motor and 13:1 gearset in there last weekend. and it is totally awesome. I have an mosfet that I will be installing this weekend too

 

I have little experience with LiPo batteries... I played Airsoft a lot almost 10 years ago and am still used to Nihm batteries. I need to change my mentality...

 

One question regarding the battery you linked (http://www.hobbyking.com/hobbyking/store/uh_viewitem.asp?idProduct=84544) For essentially £5, is it any good? How is it so cheap?! Crazy!

[Sitting Duck]

get a mosfet in there asap - luckily v3's means the fet gets fitted without having to reopen box like on v2's

 

Lipo's really offer $hitloads more grunt which you will need on 13:1 gearing and the motor will draw as much juice as you can give it

so for sake of contacts in the trigger get that fet fitted sooner rather than later

 

http://www.firestormsystems.com/shop/electronics/mosfet-switch.html

 

is one of many good small fets out there - gate pico or airfet plus others

(could make your own but for 1 or 2 guns it really ain't worth it)

 

Lipo link was for HobbyKing EU

search around the UK HobbyKing now sells them "airsoft" batteries

normally buy from UK or EU HobbyKing as quicker and no chance of import duty

be careful very easy to click and end up buying stuff from HongKong so ensure you click UK or EU warehouse

 

apart from shipping costs - nobody should be paying silly money for batteries and nobody should spend £20 for a nimah

 

you will need a new charger a B3 or B6 type but yeah lipo's depending on type/style/format/cells you should easily get stuff under £10

on normal M4's it pays the measure your battery space and use HobbyKing's battery finder

Then you can see loads of options

If people got a fixed stubby or full stock they can fit really cheap block lipo's in there

 

you should buy a lipo with at least 20c - I'd say 25c tbh

if lipo says 25c-50c = 25c is what its real rating is I've been told

 

Turginy, Zippy are good brands of lipo's

the one I linked is a popular coz it is a nice stick lipo for AK's as well under the dust cover

you do not need a 11.1v lipo - your motor & gears should be hitting 26rps+ once fetted & rewired etc...

your spring in a 110mm - 140mm barrel is likely to be about a m110 if hitting 330-350fps

so you should not be getting overspin or little

go down 11.1v you will hit near 40rps and smash f*ck out of your gearbox with Pre Engagement

so unless you are a real nutter speed freak keep it in moderation

and coz of extra work involved many keep guns firing into the 20's

twenties is plenty as they say

yes you can go nutz - but faster guns need a lot more work and simply fail quicker

 

could waffle and repeat $hitloads - do a search on here for one of my war n peace novels on lipo's n warnings

but the real answer is drop nimah and go lipo (with mosfet)

[Shepsy]

Mate... thats some quality info there.... LiPo here I come!!!

 

I've done tons of research on the LiPos and how o handle them and how they work... But didnt think I would need to take the leap over to them yet... But it seems I really should of.

 

Thanks bro.

[Lozart]

Just FYI that's EXACTLY the battery I run in my MP5K (Classic Army). It just about fits OK but it's a bit of a wiggle....

[Sitting Duck]

Just FYI that's EXACTLY the battery I run in my MP5K (Classic Army). It just about fits OK but it's a bit of a wiggle....

 

Ian uses them in AK's

and yes it is still a bit tight - poxy mp5k's

 

do NOT be tempted to get a twin stick version it will be that bit fatter once you lay the 2 haribo lipo sticks together

they do a small 1200mah single stick one

but think the 166mm long mofo one linked to is the one many go for

 

just wish they made that battery tube just a smidge bigger just a smidge to say 20mm tube - make life so much easier