Hi Terry,

I feel the 123's will become the battery of choice in due time. Only in our usage for about 2.5 years. Size and weight might of prompted the usage for IMAC but they are ok for 40-60 size. They do require a compatable charger
. There is good info at www.hangtimes.com which is NoBs Batteries website or also at FMA. The cost is reasonable and with no fear of fires.
Just noticed another source; www.sincityjets.com
John