Greetings:

I have a cordless sweeper (Shark EuroPro) which uses 6 Cells Sub C NiCd
1300 mAh. The cost to replace these cells is equivalent to 10 Cell Sub
C NiMH 3300 mAh. Is there any problem if I replace any device
(Cordless Vacum, Drill, Screw driver etc.) design for NiCd with a
different type i.e. NiMH? In other word, will the charger for NiCd be
able to charge NiMH?

Any insight thoughts would be greatly appreciated.

You should not have any trouble as long as you keep the voltage
constant, i.e., replace the six 1.2V NiCd cells with six 1.2V NiMH
cells. There should also not be a problem using the same charger to
recharge the NiMH cells. Of course, the benefit to you is a longer time
between charges because 3300 mAh will last 2.5 times longer.

You should not have any trouble as long as you keep the voltage
constant, i.e., replace the six 1.2V NiCd cells with six 1.2V NiMH
cells. There should also not be a problem using the same charger to
recharge the NiMH cells. Of course, the benefit to you is a longer time
between charges because 3300 mAh will last 2.5 times longer.

wrote:
Greetings:

I have a cordless sweeper (Shark EuroPro) which uses 6 Cells Sub C NiCd
1300 mAh. The cost to replace these cells is equivalent to 10 Cell Sub
C NiMH 3300 mAh. Is there any problem if I replace any device
(Cordless Vacum, Drill, Screw driver etc.) design for NiCd with a
different type i.e. NiMH? In other word, will the charger for NiCd be
able to charge NiMH?

Any insight thoughts would be greatly appreciated.


I'd say the answer is a definite maybe...
The situation is improving over time, but there are some general guidelines.
NiCd seem to be better in high drain applications because of their lower
internal resistance and slower self discharge.
Cells are optimized for different purposes. For a fixed size and
technology, there's an inverse tradeoff between capacity and fast charge
capability.
For slow charge applications, NiMH are somewhat less tolerant of
long-term overcharge.
For fast charge applications, the charge termination characteristics can
be sufficiently different that charge does not terminate when NiMH cells
are used on a NiCd charger. This is much worse because a charger
designed for one hour now takes three. This c/3 may not be enough to
cause the internal processes that are detected to terminate charge based
on C.
There may be a safety timer that times out based on 1300mAH and only
gives you 1/3 charge.

Safest thing to do is use the battery supplied by the vendor.
mike

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Thanks to all for your insight thoughts.

The charger doesn't have any timer or automatic shutoff. Based on your
input, I have 50/50 chance that it could work. So I am going to give
the NiMH a shot. In worst case scenarios, I will lost $20 if it
doesn't work; however, I will get my lesson "I should listen to Mike"
:-)