Naturally the new batteries should have the same technical specification as old ones to ensure full compatibility. The only exception is the most critical parameter – energy capacity given in ampere hour (Ah), this may be the same, bigger or under some conditions even smaller than existing batteries. If you insist to install batteries of smaller capacity, please consult with us. Attention: Always replace all batteries inside the UPS at the time, never mix old and new ones. Use only one type of batteries, never install mixed types of batteries.