Yep:
They can be overcharged, and thus may evaporate a good portion of the electrolite, so, they may not last as long as AGM/Gel types.
I use a battery box that is outside of my residence to power an APC Matrix 5000. It runs my computers and some critical loads inside the house. I am using the Everstart (Wal-Mart, god help me...).. 600CCA deep cycle batteries. 4 in series. Run time exceeds an hour at 90% load. (I don't know how long it will actually run or how long it takes to recharge)... All I can say is the run time is long enough for me to get my rotary backup generator online.
You will also need to insulate the battery housing if you keep it out in the cold like I do..
My only concern is the stress on the charging circuits in the UPS, but, have had no issues with it in over a year.
One other thing I should say. I have a spare Matrix with AGM packs as a standby solution, so, I don't have any issue with the current unit going T.U.... So, if you are using this on your only, critical and necessary UPS unit, I would think long and hard about doing this project...
Reply-to: netwraith@pcrd.net
thenetwraith (There is a picture here, but, you just can't see it!)