AGM Maintenance Questions
I've replaced the OEM batteries (looked more like starter batteries then deep cycle) in our new fifth wheel with Trojan T-105 AGM batteries (4 each in 2 12 volt banks so voltages below are 2 in series.) I'd like these to last as long as possible due to cost, thus some questions. I also replaced the WFCO charger with a Samlex 50 amp charger. I picked that charger partly because I can set dip switches to determine the charging profile as I plug the trailer into shore power after a day of discharging.
1) Another thread implied that it was important to absorption charge AGMs at 14.4 volts. Trojan recommends that voltage. How important is this for battery health as opposed to 14.0 volts or 13.5 volts which the Samplex may be set up for?
2) Trojan recommends absorption at 14.4 v for a maximum of 2 hours. The Samlex may be set for a maximum absorption charge of either 4 or 8 hours. Obviously I have picked the 4 hour maximum, but will that be a problem exceeding Trojan's recommendation?
3) Since a maximum absorption charging time is probably related to heat, would 14.0 volts at a maximum time of 4 hours be safer? I do have a temperature monitoring probe from the Samplex installed in one battery bank.
4) Samlex recommends that the absorption mode (dip switch settable) be skipped entirely when load such as in an RV is attached, because the charger will never see a low current flow that signals the end of absorption and a switch to float (13.5). In other words, Samplex says to set the dip switches to go straight to float of 13.5 volts at the end of bulk. Because of other indications that an absorption period of 14.4 is important, I'm reluctant to do this. The Samplex will drop out of absorption when current drops to 5 amps. This is pretty easy to accomplish by not turning on many lights in the RV, and that triggers the drop to 13.5 float. So, should I just program the 14.4 absorption for max 4 hours, assume the temperature probe will protect the batteries, and trigger float by turning off lights when I see that my battery monitor says the batteries are 100%?
Thanks
1) Another thread implied that it was important to absorption charge AGMs at 14.4 volts. Trojan recommends that voltage. How important is this for battery health as opposed to 14.0 volts or 13.5 volts which the Samplex may be set up for?
2) Trojan recommends absorption at 14.4 v for a maximum of 2 hours. The Samlex may be set for a maximum absorption charge of either 4 or 8 hours. Obviously I have picked the 4 hour maximum, but will that be a problem exceeding Trojan's recommendation?
3) Since a maximum absorption charging time is probably related to heat, would 14.0 volts at a maximum time of 4 hours be safer? I do have a temperature monitoring probe from the Samplex installed in one battery bank.
4) Samlex recommends that the absorption mode (dip switch settable) be skipped entirely when load such as in an RV is attached, because the charger will never see a low current flow that signals the end of absorption and a switch to float (13.5). In other words, Samplex says to set the dip switches to go straight to float of 13.5 volts at the end of bulk. Because of other indications that an absorption period of 14.4 is important, I'm reluctant to do this. The Samplex will drop out of absorption when current drops to 5 amps. This is pretty easy to accomplish by not turning on many lights in the RV, and that triggers the drop to 13.5 float. So, should I just program the 14.4 absorption for max 4 hours, assume the temperature probe will protect the batteries, and trigger float by turning off lights when I see that my battery monitor says the batteries are 100%?
Thanks
