Question for the Battery Experts
I have a pair of 6v CG batteries that I use to power the rolling home. Sam's Club, Ever-Ready's (220Ah). They will reach 3 full seasons about mid-season this year. They work flawlessly, and seem ag...
Forum Discussion
If a battery isn't holding a charge as well in terms of its voltage, then it's not a good idea to wire it in parallel with stronger batteries because the difference in voltage creates a differing potential which will cause current to flow from the stronger battery to the weaker one while the batteries are sitting.
However, you say that the older battery still holds a full charge, which I take to mean that it reaches a full charging voltage of around 12.6 volts. In that case, it does no harm to use the battery to increase your amp hour capacity during discharge. If it has different, maybe less, capacity then your CG's, the different sets of batteries will discharge in proportion to their differing capacities. I have several banks of batteries with differing capacities. I don't wire the batteries directly in parallel, however, they are in separate compartments.
Charging, however, may be a different story. The gel cell may have different charging voltage requirements than your CG's, so charging them together from the same converter may be a problem. The gel cell may also have a different resistance than the GCs, so it will grab a different proportion of the charging amperage. In other words the differing batteries may not charge evenly. I partly solve this problem by isolating my separate battery banks from each other during charging with relays. I use a separate charger for my AGMs.
The fact that you are also charging from solar panels adds another complication to using different batteries if all of them are tied in to the same circuit from a single controller.
But my main point is, if you have an additional battery available, why not use it? You can always charge it separately.
Miles
However, you say that the older battery still holds a full charge, which I take to mean that it reaches a full charging voltage of around 12.6 volts. In that case, it does no harm to use the battery to increase your amp hour capacity during discharge. If it has different, maybe less, capacity then your CG's, the different sets of batteries will discharge in proportion to their differing capacities. I have several banks of batteries with differing capacities. I don't wire the batteries directly in parallel, however, they are in separate compartments.
Charging, however, may be a different story. The gel cell may have different charging voltage requirements than your CG's, so charging them together from the same converter may be a problem. The gel cell may also have a different resistance than the GCs, so it will grab a different proportion of the charging amperage. In other words the differing batteries may not charge evenly. I partly solve this problem by isolating my separate battery banks from each other during charging with relays. I use a separate charger for my AGMs.
The fact that you are also charging from solar panels adds another complication to using different batteries if all of them are tied in to the same circuit from a single controller.
But my main point is, if you have an additional battery available, why not use it? You can always charge it separately.
Miles
