Thanks for the input so far guys,
But... Electricar, although I appreciate your input, your understanding of bridge rectifiers appears to be flawed, during an AC cycle, power is first chanelled through 2 diodes of the bridge, then during the second half of the cycle the other two diodes. When applying DC, dependent on which way the polarity is, one set of 2 diodes or the other is solely used, power input is not halved. Also, as the supply voltage can be anything from 100V to 240V on this type of unit the DC battery voltage (at least at 144V/156V) is well within the design range the unit can cope with and is expecting from rectified from AC, DC input voltage.
My concern isn't input, it's more about output and using these in parallel to achieve a suitable stable current supply, the point made about isolation is a good one. I will test my existing laptop supply for this, but as they can be used with up to 240V AC input, I'll be amazed if the output is not isolated.
As for saving a buck... I partly agree on this one, but controllers aside, a lot of "bespoke" EV components are often very overpriced due to the low volume demand, and are often only slightly rehashed from existing non EV equipment available for a fraction of the price due to economies of scale!