Hello:
I currently own an Ansmann 8 smart charger. It will charge NiCd batteries, but my question is can I charge NiCd Sub C (mini C) batteries in this charger, safely? I'm assuming Sub C are just like regular C batteries as far as the charger is concerned. But I was curious just to make sure.
Thanks!
CS-
Can we assume each Sub C cell has an output of 1.2 volts? In other words is it a single cell, not a package of several smaller cells?
If the cell is 1.2 volts like other NiCd cells, then you should have no trouble charging it like any other 1.2v NiCd.
Maybe twenty years ago I noticed that Radio Shack's C and D NiCd cells had the same amp-hour capacity. When I opened up one of each, I found both had the same Sub-C cell inside of cardboard tubes that made them larger on the outside.
Fred
You got to hand it to them, they know how to cut corners!
Almost everyone did that. GE, for example.
I just purchased some 5500mAh NiMH C cells. Hope they're good.
[I have no first hand knowledge of this particular charger. Having said that, you'll have to evaluate for yourself how much of the following applies -- a VOM is your friend, here]
It depends on just how "smart" the charger is. IME, most smart chargers are just a step above "a voltage limited current source".
SC cells have typical charging rates of ~100 - ~200mA. And, fast charge rates anywhere in the ~400 - 3000mA range (!)
Contrast C cells typical charge rates of ~250 - ~400 mA and fast charge rates of 4000 - 5000mA.
So, you first need to decide if your charger does standard vs. quick charging. In the latter caase, you have to verify your cells can accept a quick charge (some can't).
Then, you have to determine what sort of charge rate your charger supplies. Is it *fixed*? Is it within the acceptable range for the batteries (cells) in question? Or, is the charger *truly* smart and watches the celll voltage (and temperature?) to determine the *optimum* charge rate for that *particular* cell (I highly doubt this to be the case).
HTH,
--don
The cell chemistry determines the open circuit voltage. SC NiCd's are the same as AA, AAA, C, D, etc. NiCd's in that regard. (if they were *batteries*, then the OC voltage would be some multiple of this cell voltage)
See my other post (in this thread) regarding possible caveats to this. (Of course, this is predicated on the assumption that you want to maximize life expectancy and capacity of the cells in question. If not, you can abuse them in lots of different ways :> )
I have an Eveready charger that handles both nicad and NiMH cells. It did not terminate charge on the Eveready 2500 mAh (half-)C cells that are supposed to work with it. I simply pulled the cells when they got a bit warm.
I have a PowerEx smart charger (the C9000), which I recommend highly, but MAHA refuses to supply a C-cell adapter.
Broadly speaking, the size of the cell doesn't matter, as long as the base charging rate isn't "too much" for a cell. If the charger will handle a 2500 mAh AA cell, it will have no trouble with a 2500 mAh C cell. It can't tell the difference.
Rechargable C cells are becoming obsolete. Most of them were 2500mah or less.
AA batteries are slighlty different in length than C cells, but most devices that take them have spring contacts with enough give that you could insert a AA battery in the same spot. You can buy adaptors that fit around the AA batteries that make them into (almost) C cells.
Since the current crop of NIMH AA batteries are 2700 mah or more, it makes little sense to manufacture special ones.
The same with D batteries, but you have to use a AA to C and then a C to D adaptor.
On the other hand, I have seen advertised 10,000 mah NIMH D cells, but I wonder what you need to charge them.
Geoff.
-- Geoffrey S. Mendelson, Jerusalem, Israel gsm@mendelson.com N3OWJ/4X1GM
"Geoffrey S. Mendelson" wrote in news: snipped-for-privacy@cable.mendelson.com:
you could use the same charger,it would just take longer. C1/10 charge rate (0.1C) would be one amp.
-- Jim Yanik jyanik at localnet dot com
For a 10,000 mah battery that would take 10 hours assuming that 100% of the charge "stuck". If you slightly less, say 12 to 15 hours, then I wonder how many home chargers could handle 1 amp output for that long?
Geoff.
-- Geoffrey S. Mendelson, Jerusalem, Israel gsm@mendelson.com N3OWJ/4X1GM
All of them, that is those rated at 1A or greater.
Or (in some cases) too little. As you've noticed, a charger designed for a relatively low charging rate may not terminate the charge cycle optimally (or at all) when charging a really big cell which has a very high capacity.
As I understand it, the charge termination point for a NiMH cell is when the cell voltage stops rising (the "zero delta V" point, with a secondary cutoff being arranged by detecting the rise in cell temperature. If you charge at too low a rate, it's hard for the charger to distinguish the zero-delta-V point accurately, and the cell may not heat up enough to trip the thermistor circuit.
The charger may shut off too soon (premature detection of zero delta V, or a "failsafe" timer intended for lower-capacity cells) or may not shut off at all.
--
Dave Platt AE6EO
Friends of Jade Warrior home page: http://www.radagast.org/jade-warrior
I do _not_ wish to receive unsolicited commercial email, and I will
boycott any company which has the gall to send me such ads!
"Geoffrey S. Mendelson" wrote in news: snipped-for-privacy@cable.mendelson.com:
depends on how well they're made. ;-) many wallwart supplies (for other products) stay on 24/7 for years.
my point was that a charger outputting less than the 1/10C rate would still charge,just take longer.(a lot longer...)
I doubt any home -slow- charger puts out 1 amp. Some power tool chargers charge their battery packs in 15 minutes. (that's FAST) Most are 1 hour chargers.
My old Makita 6095 charger(9.6V stick NiCd) sources 1.5A. it gets pretty warm at the end of that hour.
it's no "smart charger",either,just pumps in the juice until the pack's thermal switch cuts it off.
-- Jim Yanik jyanik at localnet dot com
Yes, of course they are, because people who own products that take C cells have no need for them. I just threw a perfectly good Sunpak 622 Super electronic flash into the garbage for precisely that reason.
Yes, and the adapters cost almost as much as the cells.
I just ordered 5500mAh C cells made by a company called CTA.
See above.
I have an Everready NiMH charger that handles AAA, AA, C, and D cells, and
9V batteris.
The MAHA can handle four cells at once at at least that current. Buy one.
Actually, it's looking for a slight drop in voltage. The harder you pump the cell, the greater the drop. Hence, fast charging gives a more-reliable cutoff pooint.
Sh*t, I've been looking for one, or something similar, none of which exist here.
Geoff.
-- Geoffrey S. Mendelson, Jerusalem, Israel gsm@mendelson.com N3OWJ/4X1GM
"Geoffrey S. Mendelson" wrote in news: snipped-for-privacy@cable.mendelson.com:
where's "here"?
why not Freecycle?
-- Jim Yanik jyanik at localnet dot com
Jerusalem, Israel.
None to be had, and no freecycle list. The owners of the name had a disagreement with the moderator of the local list, so they closed him down.
When they were made the tax was so high that no one could afford them.
Geoff.
-- Geoffrey S. Mendelson, Jerusalem, Israel gsm@mendelson.com N3OWJ/4X1GM
ElectronDepot website is not affiliated with any of the manufacturers or service providers discussed here. All logos and trade names are the property of their respective owners.