Back when I carried a Walkie-Talkie full time, the radios used NiCads which are similar to NiMh... I found that the battery life was maximized by having (at least) two battery packs. Put a fresh one on the radio, run it until it went dead while the other pack was on a 14hour (not fast) 0.1C charge. Swap batteries, and repeat.
I used a rotary 120Vac timer set to 1 hour out of 24h to turn off the charger. It was just a matter of rotating the dial on the timer so it would click off 14h after I dropped the dead battery into the charger. After that, the timer would charge the battery for 1h every 24h thereafter, until the other battery needed charging...
Lead-Acid batteries are much easier to deal with than NiCad or NiMh. Read the charging guidance on either BU or Powerstream
I used a rotary 120Vac timer set to 1 hour out of 24h to turn off the charger. It was just a matter of rotating the dial on the timer so it would click off 14h after I dropped the dead battery into the charger. After that, the timer would charge the battery for 1h every 24h thereafter, until the other battery needed charging...
Lead-Acid batteries are much easier to deal with than NiCad or NiMh. Read the charging guidance on either BU or Powerstream