Is it bad to run two batteries at the same time?

It is a simple system. Each battery should be run to a commom block. If you are only seeing 9 volts when running, and the other one is seeing 13-14, then the battery could be bad. Each alt should also be run to the common block, for redundancy. If you have one alt charging one battery, it was done incorrectly.

What should I do if my Silverado battery is bad?

Each battery should be run to a commom block. If you are only seeing 9 volts when running, and the other one is seeing 13-14, then the battery could be bad. Each alt should also be run to the common block, for redundancy. If you have one alt charging one battery, it was done incorrectly.

Why does my Silverado charger have two batteries?

So when the alternator is charging, it is essentially charging one big battery. It charges through the first battery (think of it as a reservoir) and this charge “flows over” into the second battery. If there is a hole/leak in the second reservoir, the “flow over” will drain the first battery.

What happens if you have a hole in the second battery?

It charges through the first battery (think of it as a reservoir) and this charge “flows over” into the second battery. If there is a hole/leak in the second reservoir, the “flow over” will drain the first battery. The isolator prevents this from happening. If you have no hole/drain in your second battery, then this is not an issue.

Which is the first battery to go bad?

Always 1 that goes bad first. Not sure if it’s been said already but always replace the batteries in pairs, even if one of them passes a load test. Any difference between the batteries’ open-circuit voltage will induce current from the one with the higher voltage to the other one, which will prematurely wear out the higher-voltage (newer) battery.

What can cause a car battery to die overnight?

Leaving the headlights on can kill a weak battery in the amount of time it takes you run a short errand like shopping for groceries, but even a small interior dome light can drain a battery dead overnight.

What causes a car battery to drain while driving?

Even small drains, like the memory function in your car radio, may kill a very weak battery. Corroded or loose battery connections. Corroded battery connections can prevent the charging system from topping off your battery when you are driving. Loose battery connections can also cause problems.

What happens when a battery is charged but not fully charged?

Fully charged (according to the battery charger) but the voltage is 12.4 or less, the battery is sulfated Sulfation is the natural byproduct when the battery discharges. Naturally, re-charging the battery will reverse the sulfation crystals and turn it back into electrolyte, ready to produce power again.