How to know is a power supply may be used to charge batteries

I have used bench power supplies to charge batteries for bench-top use many times in the past. But I have always worried that the power supply may not have the protection needed to avoid damage by a voltage source (battery) applied to its terminals. Obviously, if the supply is set to the same voltage as the battery before connecting, there should be no problem. But what if I turn off the supply? I want this to be fool proof. In the past, if I was not able to determine if the supply had the needed protection, I would put a power diode in series to block any back-feeding of current. But I would prefer not to do that so as to have more precise control of charging voltage.

I suspect that most bench supplies today have such protection, but in the case of an Extech 382213 I can't tell from the data sheet or the instruction manual. Does anyone here have experience using that supply to charge batteries. It is amazingly hard to find any information about this on the web. Is that because such protection has become standard practice in power supplies?

Thanks! -JD

What kind of batteries do you need to recharge?
The use of a power supply is not very good. I have to properly limit the current.
Giovanni

Hi, Giovanni,

Thank you for your reply. In this case these are absorbed glass matt lead-acid batteries. As you say, a bench supply may not be the best way to charge them, but with correct setting of current and voltage limits it really does what I need.

My question is about the power supply though. Are bench supplies generally made with the necessary protection against damage from a battery being connected to their output terminals? From a voltage source being connected even with the supply turned off? I realize that there may be a large output capacitor in the supply that could present an in-rush current issue. Are there any other concerns, like back-feeding and damaging other circuit components in the supply? Are supplies designed these days (specifically, the Extech 382213) to allow battery charging without damaging the supply? Or must I supply my own blocking diode in series with the battery?

Thanks! -JD

Just to give an update here, my friend went ahead and connected his batteries to his Extech 382213 with no incident. The supply appears not to mind a voltage being applied to its output at all. Apparently it has the needed internal protections to avoid damage.

-JD