Hi everyone. My gumstick charger BC-9HP2 has finally packed up after 20 odd years. I had been charging up NC-6M NI-Cd and NH‐14WM-Ni-MH batteries in it. I am now having to charge the 14WM Ni-MH in my MZ-R91 mini disc player. My question is can the MZ-R91 be used to charge up the Ni-CD gumstick as well?
I am using an XTAR VC4SL (XTAR VC4SL Charger), which is designed to charge NiMH and Lithium cells, also for NiCD cells. However, I don't leave it on overnight with the (older) NiCD cells and NiMH gumsticks.
Most information about NiCads suggest that provided the charge rate is less than 1/10th of the cell capacity you needn't be concerned about overcharging. Having not used Gumsticks how do their dimensions compare to AA and AAA cells.If you got one of those old universal chargers with contacts on springs and could get a gumstick to fit in the AAA position you could use that there should be no chance of overcharging. Something like this https://www.ebay.co.uk/itm/234729073417 These things are worth very little as they would be very slow with NiMH. I will have to look at the specs of one I have.
Emiel, longman. Thanks for reply. The MZ-R91 came with the NI-MH 1400mHh so I know I can charge it up in the R91. I just want to know if I can charge the NI-Cd 600mAh in the R91. Being a lower amperage I think it should be ok. I just don't want to risk damaging the player.
If anything you might damage the battery. One idea would be to time how long the NiMH takes to charge and then charge the NiCad for just under half that time. On the subject of damaging batteries, at one point they had a 15 minute Energizer AA battery charger incorporating a fan to attempt to keep the batteries cool. The problem with it was that after about 20 charges the batteries had lost most their capacity.
With the charger I mentioned above (VC4SL) I have not noticed the NiCD getting warmer than the NiMH cells, they are both warm to the touch. Whenever the charger flashes done for the particular cell, I remove it as soon as I see it. Not overnight, it somehow does not feel right.
Emiel, Longman. Thanks for your advice. These gumsticks are still charging after 20+ years. I'm still getting between 5-6 hours play. So cannot complain. Will just charge theNI-MH in the R91 until I can get a charger for both of them.
Firstly you are super lucky to have 20 year old NiCD batteries that still charge. No such luck for me with only a NC-4WM from a wireless receiver for a WM-505 still able to charge up and retain the charge. I use the same charger as Emiel and recommend these XTAR units for NiMH and Lithium batteries. I would not charge a NiCD battery inside your MD Walkman. I have seen many older NiCD batteries swell and heat up even when used in their originally supplied charger. As they age they tend to get hot during charging and eventually fail. If that swelling happens when the battery is inside your Walkman it could be catastrophic.
Hi Silverera. Thanks for your advice. I'm using the charger-BC-7SP2 that came with my EX-615 Walkman to charge up the NC-6WM gumstick. Have been using this Walkman as my every day unit outside and this original gumstick still holds charge. Have just been very lucky I suppose.
Hi Derek. I once charged an old NC-6WM battery and was going to put it in a WM-WX1 Walkman that it originally came with. Fortunately I left it on my desk and went off to dinner. When I came back it had swelled up so much it was good only to go to a recycle depot. Had I put it in any Walkman I expect the swelling may have cracked the PCB and jammed so tight in the battery bay I would have needed to completely dismantle the Walkman to get it out. Oddly enough the swelling happened ages after I removed it from the charger. @Emiel is right. Once they're charged best to remove them from the charger!
Hi Silverera. Have just noticed one of my NH-14WM(A) gumsticks has just developed a slight bulge after all this time so I shall b heeding your advice. Will have to be careful which units I use it with. Also I always remove them from the charger once charged.
try to use imax b6c hobby charger. set 0.1A charging (its minimum posible). posible "training accu" with cicle charging - charge/discharge with check volume everytime. for charging accum. less when 1000mah, charge 2 at once. in this case you will have over 1000mah per element. just connect + to + and - to -.
