#1
so its been a while sence i got my esp ex-401 with active emg 81/85, and decided to try and switch the battery's, i had a battery i bought when i got the guitar and put it in after struggling to get out the original, this battery was bigger but i managed to both fit it in.. they were both 9v battery's so i assumed it wouldn't matter, i plugged in the guitar and it sounded like !@#$, so i through the old one back in and it went back to its normal sound. it was even harder to get this battery out.

i dont know what i should do :/ maybe a dumb question to many of you but i have no clue
#2
What brand battery is it? Maybe try and get the same brand that came with the guitar?
Guitars:
Agile PS900 Blue Flame: SD Blackouts, TonePros TOM, Grover Locking Mini-Rotomatic Tuners.
Amps:
Peavey 5150 Head w/Bias Mod.
Peavey Bandit 112
#5
Do you have a multimeter? Check the voltage level on one of these. It should be running above 8.8 volts to get the best sound. The lower it gets the more difference your gonna hear.
#6
you have to insulate the battery. You also should use alkaline batteries, not heavy duty.
Jackson RR5 ivory w/ EMG 81/85
Jackson DX6 w/ SD Distortion & Dimarzio Super Distortion
Fender Starcaster Sunburst
Mesa/Boogie DC-3
Johnson JT50 Mirage
Ibanez TS-9
Morley Bad Horsie 2
Boss CE-5

ISP Decimator
Boss DD-6
Korg Pitchblack
#7
alright. and by the way i took the dan electro battery outa my wah and it sounded the same as the stock battery, so is it just the 9v i bought?