Battery manufacturers suggest that if you are going to run multiple batteries that they be rated exactly the same. Otherwise you will have one sucking more of the charging current during a charge cycle and also one providing more power than the other during a discharge cycle. The discharge rates may also be different which makes this condition worse, especially for deep cycle batteries.
Explanation:Battery A is a 50 amp/hour battery with a nominal discharge rate of 10 amps/hour
Battery B is a 100 amp/hour batter with a nominal discharge rate of 20 amps/hour
The system is currently using 10 amps/hour total. Battery A provides 5 amps/hour of that.Battery B provides 5 amps/hour to the system, plus 5 amps/hour to battery A because it can sustain a higher discharge rate.
In this scenario battery B is th only battery actually being discharged until it gets low enough that it no longer provides power to battery A, only to the system. Battery A is barely discharged.
Now, you stop using the system and start up the charger. Battery B has been deeply discharged and pulls most of he charging amperage. Battery A gets only a trickle charge because it is showing as "full" to the charger.
If this cycle repeats every campout battery A will be destroyed because it is not being deeply cycled the way it was designed.
That being said, yes, + to + and - to - using the shortest cables possible. You may want to try running JUST the orange battery for a weekend. Camp in the driveway to test it out. It is about double the capacity of most "normal" deep cycle batteries.
G2 Trey Jung wrote:
Gerald,I'd like to add the "orange battery" I got from you to my existing Trojan deep cycle battery in the Eurovan to increase my battery time when I am camping like last week w/o AC hookups... Would I just run a jumper cable from the first battery to the 2nd (pos to pos and neg to neg or do I need some special connector)..... Trey
