adding battery bank to existing battery bank to increase battery hours

[markthespark]

Hi guys one of my clients is asking me to fit extra batteries to his existing battery set and I am not sure that this is going to achieve the results that he is requiring. He feels that because the existing batteries may not cope with the continuous load shedding experienced now that adding the batteries will give him the extra hours that he requires. Am I correct in saying that even with the extra batteries they still all require at least a 6 hour chance to recharge, and how would this affect the charger if it has to charge an extra 2 batteries?

[Isetech]

You will increase the battery capacity, but unless you have the additional charge capacity you wasting your money.

If it is a lithium battery and your inverter has a big enough charger to support the addition batteries then it should be fine.

IF they are lead acid batteries, best you check you recommended charge rate. It is recommended that you charge them at 10 %.

If you have a 100 amp/hr battery, you would use a 10 amp charger, it will take 10 hours to charge the battery, if you add one battery you will have 200 amp/hr and you can increase the charge rate to 20 amps, it will take 10 hours to charge. After chatting to a few lads from other Provinces, it sounds like the guys are getting hammered with the load shedding, some talking 4 hours twice a day.

Be very very careful you dont let your batteries discharge lower then 11.5 VDC if you have lead acid or AGM's. We lost a 4 pack of 240 amp/hr batteries within a year because the installer left the inverter at 10.5 VDC default on the inverter.