Victron Energy 12V/200Ah AGM Telecomm Batt. (M8)

AGM technology
AGM stands for Absorbent Glass Mat. In these batteries the electrolyte is absorbed into a glass-fibre mat between the plates by capillary action.  

Low self-discharge
Because of the use of lead calcium grids and high purity materials, Victron VRLA batteries can be stored during long periods of time without recharge. The rate of self-discharge is less than 2% per month at 20°C. The self-discharge doubles for every increase in temperature with 10°C. 

Low internal resistance
Accepts very high charge and discharge rates. 

High cyclic life capability
More than 500 cycles at 50% depth of discharge.