Charging 36V Nicads

Ive been looking at Hydras charging set up which is a large PSU robbed from somewhere which charges the batteries at 50V, 3A for about 45minutes.

The charger can deliver up to 6A and as we currently have dropped down to two 36V packs I was looking at reducing charge time by charging these in parallel.

I do understand there are problems with this set up.

The internal resistance of the batteries may differ meaning that they will receive an unbalanced charge and therefore possibly a different current. This is a potential risk to at least one set of batteries.

In the event of a short circuit of one set of batteries the charger will cut out. Hopefully this would be on the theraml cut out of the chareger and therefore not too much of an issue.

In the event of an open circuit on one set of batteries the full 6A current would be delivered to one set of batteries. Not a good scenario as they would burn.

I was looking at building a pair of current limiters to limit the current to 3A per side. Does anyone see a problem with that or is there more I need to do to get this to work?

I would prefer a commercially avilable current limiter so if you know where to get them let me know.

Andy