BC-900 Modification to take C / D Cells

[purduephotog]

I'm looking to get some NiMH cells C cells for my old 1.5 W flashlights... and I have an excellent BC-900 that would do the job. That is to say if the batteries would fit.

After giving it some thought and drawing up some ideas it would look as if I could use a dummy cell (non conducting, pos/neg contacts) in the charger and feed a pair of leads out to a C or D cell holder with a cell in it.

Does this seem like a reasonable approach? I could also look at going LiIon and buying another flashlight or two (always a good solution) then coming up with a way of fitting the 3.6V cell into the 2.4V chamber and dummy celling it.

Ideas welcome...

 

[odessit]

This is exactly what I am doing on Maha MH-C9000. Just waiting for break-in cycle to finish on my AA cells before trying out my ugly concoction on two LSD 4500 C cells
Supported capacity on Maha is 20 Ah, I am safe there.

 

[Lynx_Arc]

I was charging 4/5 A nimh cells with leads to them and my rayovac 1 hr charger I don't see why a dowel rod with a hole in each end with a wire stuck in the hole halfway and shove in the charger connect to a D or C cell wouldn't work well.

 

[mitch79]

The only problem I can see is the BC-900 may not terminate properly.
Even with a 1A charge that is only a 0.22C charge rate with 4.5Ah cells, even lower with the big D's.

 

[Lynx_Arc]

The only problem I can see is the BC-900 may not terminate properly.
Even with a 1A charge that is only a 0.22C charge rate with 4.5Ah cells, even lower with the big D's.

If the charger works well with 200ma on 2.5Ah cells or .1C it should suffice. I have charged 2300mah cells at 200ma with no problems but I prefer the 500ma setting or about .22C.

 

[n3eg]

I'm using dowels with screws and uninsulated crimp ring terminals at the ends, and clip leads from there to a battery holder or whatever. Be sure to use the heaviest clip leads you can find. The only drawback is the 3000 mAH battery limit. Also, don't clip two or more adapters onto two or more cells in an assembled battery pack!

 

[UncleFester]

Isn't there an amp-hour charge limit on the BC900? I think it's below your cell capacity. I could certainly be wrong here. Calling Silverfox....

 

[FatTony]

I'm using my C-9000 to cycle some 2/3 A cells and to connect them I took several lengths of wire and soldered little rare earth magnets to the ends. The magnets grip both the charger and cells very tightly and have worked a treat so far.

The little magnets I am using were harvested from a Geomag building set, they are about 4mm x 2mm, you'll need to use low heat on the soldering iron and keep the tip in contact for no more than 1 - 2 seconds otherwise the magnet will start to lose some or all of it's strength. I found that it is best not to rough up the surface of the magnet as the plating is very thin and will flake off easily afterwards.

 

[purduephotog]

I'm using my C-9000 to cycle some 2/3 A cells and to connect them I took several lengths of wire and soldered little rare earth magnets to the ends. The magnets grip both the charger and cells very tightly and have worked a treat so far.

The little magnets I am using were harvested from a Geomag building set, they are about 4mm x 2mm, you'll need to use low heat on the soldering iron and keep the tip in contact for no more than 1 - 2 seconds otherwise the magnet will start to lose some or all of it's strength. I found that it is best not to rough up the surface of the magnet as the plating is very thin and will flake off easily afterwards.

Very very clever. I get lots of magnets out of harddrives I disassemble and could do so (recently was using one as a nail finder for nail-pops in the baby's room).

I'll have to look at doing this too.

Thanks again everyone- I ordered some C NiMH batteries.

 

[Turbo DV8]

The only drawback is the 3000 mAH battery limit.

I have a Maha 808M to charge my D cells, but have oft dreamt of using my BC-900 to do a discharge capacity test. I am aware of the BC-900 charging current cut-off, but what would happen if I did a discharge on a 12 Ah D cell on the BC-900? Would the display be capable of tracking it all the way to 12 Ah discharge? Would it only go to 9 Ah because the display lacks a tens digit? Or what?

 

[boiceboy]

Anyone find out any more about the possibility of charging D-cells in the BC900? I have a BC900 on order from Amazon and currently considering drop in options for a 3D mag.

 

[was.lost.but.now.found]

The BC-900 has a stated capacity per the manual of 3 Ah, but I have no knowledge if that is electronically forced (triggering a shutdown) or just a guideline.