Adding external battery pack, should the batteries in the head UPS unit be replaced as well?

[Anonymous user]

I am getting a SMX120RMBP2U to extend the runtime of SMX2000RMLV2U, just wondering if the batteries in the UPS should be replaced as well, to make 3 RBC pack to be matched in age, make, etc. ? I know that is not a good idea to mix batteries in series, but since they are parallel (does not make sense to have 3 120V DC in series) it should be more forgivable? Does these external battery units have designs in place to compensate variations between multiple RBCs?

[BillP]

Hi Ender - 

The general rule of thumb is that if the batteries in the main UPS are more than a year old they should be replaced at the same time as adding the external battery packs. 

Liam

[Anonymous user · Accepted solution]

On 1/28/2019 9:42 AM, Liam said:

Hi Ender - 

The general rule of thumb is that if the batteries in the main UPS are more than a year old they should be replaced at the same time as adding the external battery packs. 

Liam

Thank you Liam. Is it 1 year since battery manufacture or 1 year since it was put into service?