Please remember the diodes are not just to prevent you from getting shocked by the battery.
They are also to prevent current inrush
from the battery to the charger smoothing capacitors when the charger is first plugged into the pack charging socket.
Without the diodes this current will be spectacular and uncontrolled flowing from the battery to the charger. It will cause a decent spark, may damage the chargers and charging socket pins. It will make you jump.
You can avoid it by turning on the charger to match voltages before pluging it into the car but that's not a safe or desirable working practise/protocol IMHO.
I use the following and now include them on all the UK battery rebuilds I do.
Socket on the battery lead. Plug on the charger lead.
http://uk.farnell.com/tyco-electroni...way/dp/1248289
http://uk.farnell.com/tyco-electroni...way/dp/1248281
http://uk.farnell.com/tyco-electroni...8awg/dp/133772
http://uk.farnell.com/tyco-electroni...8awg/dp/133796
Very cheap. Less than $1.00 for plug and socket. 600v rated 5A.
Add $1.00 for wire and two diodes.
http://uk.farnell.com/on-semiconduct...ast/dp/1651049
Edit
I've just ordered 4 of those 48V 25W psu's to see if they are any good.
I've also e-mailed them to see if they want to get there chinese supplier to quote for a purpose built 175v 250ma CC & CV supply.
