Try to use devices that take the same size battery. I use a gazillion Eneloop AA rechargeable batteries, I no longer use anything in d or c size. Before a trip I put freshly charged eneloops in all my devices - my am/fm radio, 2-3 good Cree torches, headlamp, mini led lantern I use in the toilet tent, my kid's nightlight & remote control toys, my police scanner which i take camping... You get the idea. I also take about 8 spare charged ones so i can swap out discharged AA's straight away and my 8 bay 12 volt charger so I can charge with my solar setup, takes about 2 hrs to fully charge 8. I charge via the camper trailer's solar at home too so for the $4 initial purchase price of the eneloop I now have 2000 recharges for free per battery. I used to spend heaps on batteries every year until I jumped on the eneloop revolution. And because I have a small solar setup it's free power for my toys!
Cheers