Batboard

We are going to start deploying a couple SLR 1000 repeaters in a rainy and wet area. Has anybody found a good outdoor solution for a battery backup?

Just my opinion but a pair of known good car type batteries in parallel with a solar battery charger
would be a good start with the solar charger keeping the batteries topped off.

PS - The battery box would of course have to be for outdoor use and weather sealed.

Note: You did not say whether these repeaters will be wall or pole mounted.