OT: SLA batteries

[vqdriver]

anyone know about sealed lead acid batteries?

i have like dozens of these in emergency lighting fixtures in our buildings and every time the power goes out they all deplete and don't seem to want to recharge. when new, they'll run for about an hour. thereafter, the batteries last about 10 minutes and done. new batteries solves this but obviously that defeats the purpose of 'rechargeable' batteries.
the fixtures themselves are actual ul listed emergency light fixtures.
ideas?

[OldCrank]

Don't know your particulars but I used to struggle with fluorescents and badly-written requirements.
Most backups constantly overcharge (and thus dry out) batteries pretty quickly. Add high temperatures to that and the only winners are battery manufacturers.

[Mark McM]

I'd look at the chargers. SLAs like to have a continuous trickle charge - not too much, and not too little. Perhaps the chargers aren't working, or are under/oversized for the battery.