You can see which battery pack Traxxas recommends for your vehicle here:

F949-5 Landings-hjul - reservedel til F949 fjernstyret fly

outdrives (XP032) - original spare part for Volcano XP4

and anything else that requires a USB port for charging

Avoid breathing in vapors—make sure there's plenty of fresh air

Batteri AAA (4 stk.) Hammer You can see which batteryGP Super Alkaline 4 pcs. AAA alkaline batteries with high performance, perfect for your radio transmitter! These batteries strike a great balance between high output and performance. You'll get the best performance in your RC control by using alkaline batteries instead of rechargeables. Alkaline batteries offer higher output (1. 5V vs. 1. 2V) and maintain power longer.