Why do some manufacturers say that 90% initial capacity is OK, while others claim 100%?
It is normal for lead-acid batteries to show an increase in capacity over the first year of two of operation. Normal factory formation procedures result in a battery that is capable of delivering somewhere between 90 and 100% of nameplate capacity, and most manufacturers deliver lead-acid batteries in this condition. The available capacity for a vented battery will generally rise to a peak of 106-110% over time. At least one manufacturer carries out additional cycling to bring all batteries to 100% of rating, and this is also done with some higher-quality VRLA batteries. Some users are not confident that the full capacity increase will be realized, and specify 100% capacity upon delivery. However, depending on the manufacturer, they may pay extra for this. Generally speaking, it is best to build up a track record with a particular manufacturer: if the available capacity typically rises to over 100% after shipment at 90%+, there is little to be gained by specifying 100% on delivery. Nic
