Hi,
Yes always include and diode in series for your safetyy!Modern batteries get more and more energy and many quickly forget this and how dangerous it can be.
People are walking away from the installation that charges the batteries etc.
Of course I am aware, that some power supplies can stand it if you reverse the + and -, but there are not many of them, especially in the hobby circuit.
Even if you would not reverse the polarity of the battery to be charged, it can still go well wrong.
If the power supply is turned off power transistor can get a reverse voltage, not every power supply has a diode built in for this.
Another example, the battery is 24V and the power supply is set to 5V, BANG! if you don't use a diode.
And I know of other situations that can cause battery charging to go wrong....
Charge batteries with chargers made for that!Still use a Power Supply, then include a suitable diode!
Charge Li-Ion? use a suitable charger!
I know many who disregard this advice, on a Dutch forum the same discussion, and then find it strange that their Power Supply burns out....
Comments like this then come along, if I include a diode I can no longer charge exactly to 4.25V,
that's what I mean, take a suitable charger and not your Power Supply.
But, do what you yourself find suitable, I choose safety, this to keep my measuring equipment in one piece and then my LAB does not burn down.
And now let's wait for the first one to come forward with the comment that he has been doing it for years without a diode
and has never had any problems, good for you!
Kind regards,
Bram