Yes you can.
Albeit other ways, and you will need to be using an extra battery too, you
can power all your 12v with the one charger and battery, and add a second
battery and charger for your 24v needs. Simply connect the extra 12v battery
negative to the 12v battery existing with 12v charger existing positive.
Your extra charger negative will connect to the new battery negative. The
positive of your extra charger will connect to the extra 12v battery
positive. Now you have two separate batteries charging on two separate
chargers. Neither will interfere with the other.
Your 24v requirement will connect by using the positive of the now added 12v
battery, and the negative of the existing 12v battery to give you the 24v
you want. Again, you daisy-chain your batteries to get the 24v, tapping the
first 12v battery to get the 12v you need, and separately charging each of
the two batteries with 12v chargers to keep them charged.
Now you could use one 24v charger to do all this, and still just "center
tap" the batteries for your 12v needs, or using one diode, you could charge
both 12v batteries with one 12v chargers, and still daisy chain the
batteries for your 24v needs and center tap for your 12v needs.
You should use care and caution by marking your wires with gray duct tap and
a black sharpie pen to keep track of your volts, and polarity as you wire
since it won't be long after wiring you can easily confuse which wire was
what. Use pieces of cut off hose to keep wires from chaffing sharp edges.
Use cardboard on top of exposed battery terminals to keep things from
falling onto/into avoiding sparks, etc. The carboard will eventually crumble
but easily replaced. Remember 12 and 24 volts is a lot, will a lot of
amperage. Take care because mistakes cause wires to glow like the elements
in your toaster. Just use common sense and care. Yes, you can very safely do
your 24v goal, but you really should do it with two batteries, not just
daisy chaining two chargers.
Finally, daisy chaining just two chargers won't be very successful because
chargers by nature get their controlled voltage, their full wave dc, and
controlled ampere output from the battery which also acts as a capacitor for
the charger. Without the battery, the charger may not work, may run "wild"
and often cause a radio humming. You won't be happy running anything
directly off a charger without using the battery in place with it.
-Eddie- (713)694-8084 24hrs or email, EddieHuffstetter@hotmail.com
>>Can I hook two of the 12 VDC power supplies together (positive to positive and
>>negative to negative ) and attach the output to the 24 volt device I'm
>>working on? Will I get sparks and smoke if I do?
> No smoke, but only 12 volts still...
>
> However, if like many cheap power supplies, they have outputs isolated from
> ground, you can hook them up in series, positive of one to negative of the
> other, use the negative of the first and the positive of the second for
> your power and you should have 24 volts. Just make sure there is no common
> chassis negative connection between them on the output side meaning that
> they can't short between the chassis.