Just found some batteries on “unman” thanks to you guys on here but not sure, is there a capacity limit on what you can use.
Looked on the Ifight web site and they state 850mah for my protek 25 but Iv seen some 1300.
Surely as long as there 4S with a XT30 connector is doesn’t make a difference, just extra fuel in the tank??.
Extra fuel comes at a cost of extra weight a 1300mah pack will be significantly bigger than an 850mah and will weigh alot more. Depending on your motors and the thrust generated by them will depend if your quad is capable of lifting the extra weight or not.
Hope this helps 
Size difference:
Left a 850mah 4s
And Right 1500mah 4s
The three main things that make a quad fly efficiently is the Motor Prop and Battery. And the thrust to weight ratio. Bigger tank doesn’t equal longer flight time because your quad will need to work harder to lift the extra weight therefore will use “fuel” at a faster rate.
It’s also a fine balance between efficiency and handling a more aggressive prop will give you a more grippy feel in the turns and will be more snappy good for freestyle but at a cost of efficiency so your flight time will be reduced.
A less aggressive prop will give you more of a flowing feel and will be far more efficient giving you longer flight time so is more suited to long range cruising style quads or cinematic style flying.
Cheers buddy I see what your saying, looking at that 1500 I’m not sure it would even fit mine 
That said they say mine can carry a naked go pro 
I’m not sure il be doing any free styling at the mo as I’m still in trainer mode …lol. I think ill stick to the 850, just have to keep looking on the net see what I can find…
Bloody minefield this, try to find a good quality battery and at a reasonable price as everything seems to of gone up or out of stock 
…
I tend to put myself on the email list at HobbyRC for my batteries they generally get new stock every couple of weeks and they pretty much fly off the shelf as soon as they come in so the email list is a must
Thanks for your help and advice mate much appreciated, well iv just done some Math and the 1300 weighs comes in at 149g and an 850 at 96g.
Add a naked go pro which Iflight claims mine will take at 96g and I will be under by 43g using 1300 battery.
Christ is this what my Saturdays have come too …lol
So like you said it might slow my quad down a bit but not a bad thing while I’m still learning, and at some point I would love to invest into a larger freestyle so could use the batteries on that 
agree or disagree ???
But that wont be for a while as I shit meself flying my cinewhoop … 
Yeah they will work on a bigger freestyle quad as long as its 4s as well personally I’d buy 1 to start with to see how it flys with the extra weight so if it doesn’t fly so good you’ve only lost £20 rather than much more if you buy 4 or 5 packs. Test one if it flys ok then pick up more
Or alternatively buy a bigger quad🙂 That way you don’t loose £20 but gain another quad. And you can never have too many quads.
Well another 1 if not 2 are on the horizon 
Fancy 1 of those TinyHawk 2 or a Trans Tec Beetle for flying round my close, but also something bigger for free style.
Tooooo many to choose from
Yep makes scene to me il get one ordered, I want 1 of those foam liners for me goggles as well, getting delicate in my old age…
Il be wearing Hush puppies before I know it
