We have two of them - used quite often over last 3 years.
Not a bad piece of kit but have had A/D failures on both so can't rave about reliability too much. Time/cost to repair isn't too good either.
However, when properly set up you do get a fairly good report to baffle the Customer which includes intercell impedences which can be very helpful in locating poor connections. Good feature is the testing setup which can be programmed as to the battery bank being tested and then allows you to march along the string without needing to go back to the meter again - it just 'knows' when you have read the cell and are moving on. Watch this one though as a couple of retries to get a good connection on a cell can get teh unit thinking you've moved on. On the poor side is the lack of ability to program in multiple strings. We have sites with 12 strings of batteries in parallel and in order to get meaningful titles to the reports you have to set the same details up 12 times.
All in all a reasonably good piece of kit - though they aren't cheap!
I guess you mean swelling and deformity? If so is most likely a mismatch between the capacity required and the capacity of cell/s you are using. When used near typical short circuit currents cheaper cells will fail. A SLA batery will typically give you 20x AH capacity when short circuited. Batteries built to correct standards are type tested to withstand a short circuit for 1 minute without bursting or leaking - I suspect that the ones you are using are not to this type of standard as well as being too small for the task.
Is anyone familiar with the On-Line Monitoring/BTech battery monitor? I have heard that it is easier to install and more cost effective than the others