18' Series AGM Batteries in Expanda
- Thread starter Brad77
- Start date
If you have the Drifta panel I think you need to configure it with the additional capacity, otherwise it will think your battery is dead when you have only drained 1/2 of your capacity.
Unfortunately @Brad77 , the Setec will only charge (at 10 to 15 amps depending on model) to a max of 14.0 volts and this is below the optimum voltage for charging an AGM to its fullest storage capacity. AGMs need 14.4 to 14.7 volts as normally shown on side of AGM batteries for cyclic use. Setec is good for GEL batteries as they only need 14.0 to 14.4 volts - all figures refer to ambient temp of 25C. A multi stage "smart" charger will get the AGMs to the recommended voltage and the Setec will then do a good job of maintaining "float" (or maintenance) voltage after that if necessary. Incidentally, why limit yourself to only 100ah batteries when you can obtain good 130ah batteries for the same (or near) price and the same physical size too?? It may take a little longer to charge both batteries connected in parallel, but you can have 260ah capacity instead of only 200ah. Setec would have no problem keeping batteries at float voltage of approx 13.8 volts and would also be capable of charging both batteries to 14.0 volts, but above that, you need a "smart" charger. Suggest one with at least 15 amp capacity.
Also, depending on the quality and charge/float settings of your solar controller, you may find it will get the voltage up to close to these figures, better than the Setec. Check specs for controller.
Last edited: