I have a FX5. I picked up rechargeable AA batteries when I could get a good deal on them$$$$$. I have 4 each Foxpro battery holders and 4 sets of 8 each chargeable mAh batteries. All have a mAh rating of 2400 or better. I have them all charged and when I feel the power pack is getting sluggish I remove the FX battery holder and inset a new one with fresh batteries..
If for some reason I do not use one of the pre-charged battery packs after a month or so...I recharge them again since mAh batteries lose power fast. if the mAh rating is less then 2400 I do not even use those batteries in the FX5. I will use them in other flash lights and such..
I also have two battery packs that are used to run small appliance, electronics, and or jump a car battery...I have used this type of storage battery to run my FX5...This has been used but the battery of course is big but is mobile and has a handle on it.. Just might use this if I was going to power the Jack In The Box also with the FX5. FP also sales a battery like this that will last longer then 8 AA's.
Remember... The FP FX5 or FX3 will work at 250 yards away with a remote. However make sure if your going to do this that your batteries have been recharged recently. also all remote caller should be elevated when using a remote.. Hang it on a hook from a tree branch, place it on some old farm equipment, or on a bale of hay etc etc etc so that the command goes right to the caller.. placing the FX series calls on the ground for long distance calling can result in failure and you not calling anything in..
By the way elevating remote caller pertains to them all Scorpions, FX_ Fury, Powerdogg, JS Preymasters etc etc etc..
Also stay away from the FP charger that will charge in the car lighter and in the house (Dual purpose)... Purchase the one that you charge direct to the caller in the house only. IT seems to perform a better charge then the Cigarette's Lighter and in house attachment charger.
Actually I use those Wall Charger that comes with the AA batteries..The Energiser charger works excellent for FP charging.. However of the AA batteries the AA Energiser batteries are not my favorite brand.