Which would you install?
I am going to be running 2 new batteries on our Jayco 17Z hybrid this year. We have a big MSW inverter, I think it's over 2000w, but we won't be using all of that obviously. I tried a single group 2...
Forum Discussion
Given enough time most any fraudulent device can recharge a battery.
When saturated voltage charging a battery, there is a MINIMUM time in minutes that the battery can be recharged. The argument is with chemistry not with slide rule prestidigitation or quaint manufacturer's references to Edward Teller, or Enrico Fermi, grade algorithms. I wish people would a) understand this b) deal with it.
Time limits are absolute. Given too little time, chemical reactions cannot take place no matter the color or design imprinted on the sorcerer's hat in the converter ad.
The ONLY way to rationally deal with a severe time constraint is similar to the following...
Relationship ampere hours consumed daily versus ability to recharge.
Batteries recover slowly from >80% to 100% state of charge.
Therefore, make available enough ampere hour capacity in the 50% to 80% state of charge region to allow maximum charge potential. If it takes one battery or twenty to do this, that's life.
So, for example given a two hour charge time window, the full 120 minutes is spent at or near maximum charging amperage limit. Configure the number of batteries needed to do this as closely as possible.
So the majority of time, total charging amp hours is limited to at or near 80% state of charge.
There has to be frequent "economy days" in which a bare minimum of ampere hours load is consumed and the charging does it's best to fill 80-100%
Constant less-than-100% recharging will sulfate batteries.
So the maximum safe constant voltage charging events are severely limited. 14.8 volts is what I recommend. 1000 amp hours of batteries at 50% state of charge? Do whatever it takes to achieve 14.8 volts instantly when the charger is enabled. If it takes 200 amperes to achieve "saturated voltage charging" so be it. Saturated voltage charging is far less harmful than severely chopping the state of charge when the potential exists to increase it. To wit -- an 80% SOC battery sulfates slower than a 70% state of charge battery.
Charging at 100 amperes for two hours beats charging at 40 amps when a hotel burden is more than 50 ampere hours daily.
This isn't a numbers game...it is a chemistry game
When saturated voltage charging a battery, there is a MINIMUM time in minutes that the battery can be recharged. The argument is with chemistry not with slide rule prestidigitation or quaint manufacturer's references to Edward Teller, or Enrico Fermi, grade algorithms. I wish people would a) understand this b) deal with it.
Time limits are absolute. Given too little time, chemical reactions cannot take place no matter the color or design imprinted on the sorcerer's hat in the converter ad.
The ONLY way to rationally deal with a severe time constraint is similar to the following...
Relationship ampere hours consumed daily versus ability to recharge.
Batteries recover slowly from >80% to 100% state of charge.
Therefore, make available enough ampere hour capacity in the 50% to 80% state of charge region to allow maximum charge potential. If it takes one battery or twenty to do this, that's life.
So, for example given a two hour charge time window, the full 120 minutes is spent at or near maximum charging amperage limit. Configure the number of batteries needed to do this as closely as possible.
So the majority of time, total charging amp hours is limited to at or near 80% state of charge.
There has to be frequent "economy days" in which a bare minimum of ampere hours load is consumed and the charging does it's best to fill 80-100%
Constant less-than-100% recharging will sulfate batteries.
So the maximum safe constant voltage charging events are severely limited. 14.8 volts is what I recommend. 1000 amp hours of batteries at 50% state of charge? Do whatever it takes to achieve 14.8 volts instantly when the charger is enabled. If it takes 200 amperes to achieve "saturated voltage charging" so be it. Saturated voltage charging is far less harmful than severely chopping the state of charge when the potential exists to increase it. To wit -- an 80% SOC battery sulfates slower than a 70% state of charge battery.
Charging at 100 amperes for two hours beats charging at 40 amps when a hotel burden is more than 50 ampere hours daily.
This isn't a numbers game...it is a chemistry game
