Battery charger with Load. Would this work?!

[jst3712]

Referring to my attachment, my question is:

Would there still be a voltage drop at the battery (SLA1) if a load is connected at the Output, despite having 2 constant voltage regulators connected together instead of 1?

I know, for sure, that there will be a voltage drop if I had just the single regulator, but cannot test the outcome of having 2 as I don’t have the right parts at home.

REG1 is primarily the “float charger” for the battery (also connects to the Output), and REG2 is the main power giver for the Output when AC power is available. When AC power dies, the battery takes over.

Output current consumption wouldn’t be anything higher than say 1.5A.

I didn’t pay particular attention to component values in my schematic, but you get the general idea of what I’m on about

Thanks.
Jason
(Learning!)

 

[MikeMl]

Using two supplies in this way wont do anything that couldn't be done with a single power supply.

After a power failure, the voltage will sag due to the internal resistance of the battery, and as the battery discharges, so the voltage will not be very constant. What voltage are you really trying to maintain at the load?

13.5V will float a SLA battery (at room temperature), but will not recharge very well it after power is restored. That requires a much more complicated charger.

 

[jst3712]

Using two supplies in this way wont do anything that couldn't be done with a single power supply.

After a power failure, the voltage will sag due to the internal resistance of the battery, and as the battery discharges, so the voltage will not be very constant. What voltage are you really trying to maintain at the load?

13.5V will float a SLA battery (at room temperature), but will not recharge very well it after power is restored. That requires a much more complicated charger.

Ok, thanks for the info.
Can you suggest a circuit at all that I could use where a load can be connected in parallel? I really am having difficulties in finding such a beast. All chargers out there seem to be a standalone charger and that's it.
Regarding the voltage at the load output, anywhere around 12-13V is fine... but that's not my main concern here.

 

[MikeMl]

What could be simpler?

Use a Schottky diode, which is only needed to prevent the battery from discharging backwards into the power supply after the AC power fails. The supply needs to be current-limited to about 3A to protect the supply, and to limit the battery charging current when the AC is restored.