"Following discharge, constant current charge the CR-165 battery at 20 amperes until the battery voltage measures 2.42 volts per cell (9.68 volts open circuit voltage)."
Sorry I see from the fax that it said 6v. This doesn't square with the 9.68v that you quote . For 6v the figure should be 7.26v for 3 cells at 2.42v.
Manufacturers give charge details based on the assumption that you charge them in one go with no discharge taking place at the time. They normally give details of a bulk charge, then an absorption phase at constant voltage and when the current drops to a certain level they consider it fully charged and normally drop to a lower float charge to maintain the state.
What I meant about recent history was that if you have charging and discharging going on together as in any normal active system, the charge algorithms are completely messed up. It is far more difficult to decide on the state of charge. Various controllers have different approaches to this, none of which I think get that close to the ideal but we have to live with it.
For normal operation the best you can reasonably do is get the things charged through the bulk phase as quickly as your input will allow, The longer they stay discharged the more likely they are to sulphate. You can't rush the final stage and it is in this final stage that the previous charge/discharge history messes up your prospects of deciding the point at which they are finally charged.
With wind there are often far from ideal conditions. If you discharge to 70% then it would be nice to get them back to less than 50% discharge quickly but if there is no wind for a week this is something you have to live with.
The data in the fax looks normal.Those batteries seem to be 220Ah at C20 rate. If you are pulling significant current with inverters they will be way below this. At typical inverter loads that many use you may be down to the 130Ah figure for 2 hour discharge if you continue loading at that rate.
Flux
