Biggest battery that'll fit in an M249 para handguard?

[Lollingsgrad]

I'm looking at this one,

https://rover.ebay.com/rover/0/0/0?mpre=https%3A%2F%2Fwww.ebay.co.uk%2Fulk%2Fitm%2F231988856225

Would it fit? Could I go bigger? I'm aware of the mod to get the battery in the box but I'd like to avoid any modifications till the warranty runs out.

 

[Esoterick]

That link goes to a selection for what battery type you would like. It would be helpful to specify which of the mAh ratings you are looking at.

 

[Lollingsgrad]

That link goes to a selection for what battery type you would like. It would be helpful to specify which of the mAh ratings you are looking at.

Click to shrink...

Sorry! It's the (S) 2600mAh 25C cranestock.