Umarex(rebranded src) mp5 and 11.1v li-po?

[Fewik]

As the title states, is it ok to run my mp5 with an 11.1v 30c lipo? I've seen Various sources claim motors burning out and trigger contacts wearing out to an issue with the gear setup? The motor shouldn't burn out to my knowledge and I don't believe the gun has a MOSFET, I have tested the battery and it seems fine, I don't intend to run it full auto ever so I fail to see how this will negatively impact my guns performance or lifespan?

[Cannonfodder]

I always laugh a little whenever someone posts about how guns must be upgraded to take LiPos as I've been using them in stock guns for years with no problems

[BigStew]

11 minutes ago, Cannonfodder said:

I always laugh a little whenever someone posts about how guns must be upgraded to take LiPos as I've been using them in stock guns for years with no problems

7.4v yeah they don't need touching but the OP is talking about 11 1v with out a mosfet. You'll at least risk over spin in semi. Maybe damage trigger contacts.

[Cannonfodder]

5 minutes ago, BigStew said:

7.4v yeah they don't need touching but the OP is talking about 11 1v with out a mosfet. You'll at least risk over spin in semi. Maybe damage trigger contacts.

I've been using both 7.4 and 11. 1 volt LiPos for a few years (probably 50/50 semi or full auto) with no issues 

Edited June 6, 2022 by Cannonfodder

[Fewik]

19 hours ago, Cannonfodder said:

I've been using both 7.4 and 11. 1 volt LiPos for a few years (probably 50/50 semi or full auto) with no issues 

Oh that's good news considering I bought the battery already, a quick question about charging it however.

 

I have a balance charger for lipos that came with an RC helicopter of mine, it has both a 7.4v and 11.1v charging plug, all my other batteries charge just fine, however my new 11.1v will charge, before the balance charger does a sort of reset, powers back on and charges for approximately 5 seconds before repeating over and over, it would suggest to me there's a short or the battery is drawing more than what my balance charger is capable? Can I still use this or look to invest into a new charger? Considering the voltage output is rated much higher it's confusing me.

19 hours ago, BigStew said:

7.4v yeah they don't need touching but the OP is talking about 11 1v with out a mosfet. You'll at least risk over spin in semi. Maybe damage trigger contacts.

How big of a problem is overspin? My gun has a trigger that is only effective up to a certain pull, what I'm saying is I pull my trigger and it reaches a point where it goes no further, once the gun has completed a cycle however I catch or something is released allowing the trigger to follow all the way through, after that point the motor and everything seems to stop very quickly, or is this the standard for aegs? I'm new if you couldn't tell

[Rogerborg]

That's rather concerning.  Do you have a multimeter that you can use to test the battery voltages, across each cell (using the balance connector) and across the whole battery (at the Deans / Tamiya connector)?

 

As to using 11.1V, go for it.  Everything in airsoft guns is consumable.  If you're not getting overspin and double-taps on semi, enjoy the win.  You'll be getting more arcing across the trigger contacts, but that's a £5 part.  Adding a cheap diode to the motor can (it seems) help it survive.  I've put them on mine for ritual purposes.

 

 

[Fewik]

On 07/06/2022 at 10:37, Rogerborg said:

That's rather concerning.  Do you have a multimeter that you can use to test the battery voltages, across each cell (using the balance connector) and across the whole battery (at the Deans / Tamiya connector)?

 

As to using 11.1V, go for it.  Everything in airsoft guns is consumable.  If you're not getting overspin and double-taps on semi, enjoy the win.  You'll be getting more arcing across the trigger contacts, but that's a £5 part.  Adding a cheap diode to the motor can (it seems) help it survive.  I've put them on mine for ritual purposes.

 

 

So after some testing the battery and charger are in spec, neither are fluctuating at all, both rock solid where they should be, the charger does say however after digging through the manual 2 and 3 cell lipos only, my battery has 4 so that is likely the cause although I don't actually understand how cells affect the ability to charge but here we are.

 

I appreciate the advice and help you've given me, as for the diode I'll pass, I'm a very casual player, looking for a bit of fun dressing up as John wick and James bond on occasion, so I'll give that a pass but you've helped me out a lot, I really appreciate it, enjoy yourself on the field of course.

Felix

[Rogerborg]

9 hours ago, Fewik said:

the charger does say however after digging through the manual 2 and 3 cell lipos only, my battery has 4

 

I'd hope not.  Lithium cells are (nominally) 3.7V each.  2 cell = 7.4V, 3 cell = 11.1V.  A 4 cell lipo or li-ion battery would be 14.8V.

 

If you're looking at the number of terminals and wires on the balance port, that'll be cells+1, e.g.:

 

[Fewik]

45 minutes ago, Rogerborg said:

 

I'd hope not.  Lithium cells are (nominally) 3.7V each.  2 cell = 7.4V, 3 cell = 11.1V.  A 4 cell lipo or li-ion battery would be 14.8V.

 

If you're looking at the number of terminals and wires on the balance port, that'll be cells+1, e.g.:

 

My cell is I believe what you call a block? Pictured below is what I have but as I stated it doesn't appear to be doing anything wrong. There's a video of the charging sequence too.

Just now, Fewik said:

My cell is I believe what you call a block? Pictured below is what I have but as I stated it doesn't appear to be doing anything wrong. There's a video of the charging sequence too.

For some reason just the music I'm listening too is present not the video sorry

4 minutes ago, Fewik said:

My cell is I believe what you call a block? Pictured below is what I have but as I stated it doesn't appear to be doing anything wrong. There's a video of the charging sequence too.

For some reason just the music I'm listening too is present not the video sorry

https://youtu.be/tOFln2-n1S0

[Rogerborg]

13 hours ago, Fewik said:

My cell is I believe what you call a block? Pictured below is what I have but as I stated it doesn't appear to be doing anything wrong

 

That's fine, it's a 3-cell 11.1V lipo.  Perfectly reasonable for airsoft use.