Battery charging

[boscoe99]

My house has a single source of electrical power. One set of wires into the house to a CB panel and from the panel a number of wires go out to various receptacles.

I turn on a LED bulb. It draws X current.

I turn on a refrigerator. It draws Y current.

I turn on an electric oven. It draws Z current.

The devices are all connected in parallel with each other. They are all supplied with the same amount of voltage. They each draw whatever current they draw as a function of their internal resistance/impedance/etc. Everything normally works absolutely fine about 99.999% of the time.

Batteries when being charged act as electrical loads. Similar to the LED bulb, the refrigerator and the electric oven.

When an outboard motor is running it provides a single source of electrical power. From the electrical generator. Power goes to a fuse panel and then on to a number of electrical devices that are connected in parallel.

Why do you suppose that there are so many cautions against connecting different types and ages of batteries to the electrical system when the batteries are connected in parallel? I read about damaging the batteries or damaging the generator. Where does this stuff come from?

[gtreanto]

Could it be balancing the voltage between batteries? IE a strong battery will only be as good as the weakest? Think of two barrels of water connected by tube on the bottom. Fill one you fill the other till they balance. If you connect a normal and deep cell battery one discharges faster and would bring the other down. I'm throwing out ideas..

[fairdeal]

I read about damaging the batteries or damaging the generator. Where does this stuff come from?

It would make for an interesting psychological study:
why the mumbo jumbo of "charging profiles" and other internet battery lore seems to resonate so strongly for some people.

"Using a deep cycle for starting will harm it" grates on me the most.

And I suspect "don't store a battery on concrete" is still alive and well...