As both NiCad and NiMH cells give the about the same voltage (1.2v), the charger for one will probably work on the other. As frollard says, watch the heat. Don't try it on rechargeable alkaline cells as they are 1.5v, and Li-ion cells are even higher, so your charger just won't have the voltage to put back the juice.Don't even consider using it on ordinary cells. That would be an invitation to getting a face full of caustic stuff.
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Googling it, I find a lot of 'combo' chargers - you just need to apply the right voltage, and not too fast.
Charge until the battery begins to warm - when the battery is full, instead of absorbing energy, it will simply output the extra power as heat. Estimate using the amp-hour rating of the battery, and the amps of the charger.
If you have a 4000mAh battery (4Ah), and a 1 amp charger, it should take about 4 hours.