Yes, you can use a bench powersupply like the ones
you’ve used in the school sciencelab. You can buy
them from Dick Smiths and electronics shops… ppl
use them also for powering their CB Radios at home
when its out of the car/bus/truck. These will
supply 13.8V DC which is fine for chargers.
You must use one with enough current capacity.
eg If your charger can charge 5A, your PSU must
be rated to pump out 6A or better (@ 50% duty).
More headroom the better… but of course they get
dearer and heavier as they get bigger. A good PSU
is never cheap but lasts forever.
Or you can buy a RC charger that runs off 240V.
CDC makes a good one ($500), I use a Novak Ionic
off 240V and there’s other cheap ones under $100 too.