Lacrosse BC-900 Charger Questions

[funkychateau]

I'm strongly considering purchase of the BC-900 charger kit (8 batteries, 8 C/D adapters, travel bag) for $40 from Amazon: http://www.amazon.com/dp/B00077AA5Q/?tag=cpf0b6-20

One of my main anticipated uses of this device is the "capacity measurement" function .... sorting my collection of AA batteries into matched sets of 2, 3, and 4 to use in various cameras, radios, flashlights, etc.

What I can't seem to find is a technical description of how this capacity measurement is actually performed. What does the charger do to measure capacity?

I would HOPE that it starts from full charge, and then drains the battery at a (user-selectable) rate until it reaches a (user-selectable) cutoff voltage, and then displays the result forever until I return to read/reset it. But that's probably too much to hope for.

Does anyone who owns this charger know the true algorithm?

Also, is $40 for the kit at Amazon (no tax, free shipping) the best deal?

BTW, Amazon also has the BC-700 for $30, but it doesn't come with any accessories, so this seemed like a better deal. If the BC-700 was $20, I'd probably go for it instead.

thanks!

 

[Marduke]

The test function charges up to full, discharges at half the charge rate to the cutoff, which is hard coded. It then charges the cells back up. It does continue to display the discharge capacity.

 

[funkychateau]

The test function charges up to full, discharges at half the charge rate to the cutoff, which is hard coded. It then charges the cells back up. It does continue to display the discharge capacity.

So does that mean I can't test capacity of cells charged elsewhere, because this one will "charge them again" before performing the test?

Also, is the charge current (and therefore discharge current) selectable for the test function? For example, if I want to know the capacity at 250 ma discharge rate, can I force the BC-900 to do this by setting the charge rate to 500 ma?

Have you measured the low-voltage cutoff to see what it is?

thanks!

 

[Mr Happy]

So does that mean I can't test capacity of cells charged elsewhere, because this one will "charge them again" before performing the test?

To do exactly what you want to do, you are going to get recommendations for this.

So to get that out of the way, there it is. It will allow you to do a discharge down to 0.9 V at any rate selectable from 100 mA to 1000 mA and then display the result until you come back and look at it. It also has a very nice 'break-in' feature that helps recover badly performing cells to peak performance.

 

[Marduke]

So does that mean I can't test capacity of cells charged elsewhere, because this one will "charge them again" before performing the test?

Also, is the charge current (and therefore discharge current) selectable for the test function? For example, if I want to know the capacity at 250 ma discharge rate, can I force the BC-900 to do this by setting the charge rate to 500 ma?

Have you measured the low-voltage cutoff to see what it is?

thanks!

It will quickly figure out charged cells are charged, and switch to discharge mode.

The charge current is anywhere from 200mA to 1.8A, and the discharge current is half of whatever charge current you select in that range.

I don't recall the exact voltage cutoff, but it's .9x

 

[TakeTheActive]

...The charge current is anywhere from 200mA to 1.8A...

Not exactly.

---snip---
Charge    Current    : 200mA, 500mA, 700mA, 1000mA, 1500mA*, 1800mA* (*limit 2 channels)
Discharge Current    : 100mA, 250mA, 350mA,  500mA,    N/A,     N/A  (Charge Current/2)
Trickle   Current    :  10mA,  25mA,  35mA,   50mA,   75mA*,   90mA* (Charge Current/20)

TTA's NiMH/NiCD Battery Charger Specifications Thread: La Crosse BC-900

 

[funkychateau]

To do exactly what you want to do, you are going to get recommendations for this.

So to get that out of the way, there it is. It will allow you to do a discharge down to 0.9 V at any rate selectable from 100 mA to 1000 mA and then display the result until you come back and look at it. It also has a very nice 'break-in' feature that helps recover badly performing cells to peak performance.

It does appear to be similar to the Lacrosse, but with the exception that you can independently select the charge/discharge rates rather than be stuck with a 2:1 ratio. Marduke noted that the Lacrosse terminates discharge at ~0.9V, and the PDF manual on the Maha says 1.0 V, so very similar there also. What I like about the Lacrosse is the separate displays for each of the four stations, and the user-reported differences in ease of programming. Also the price - if I value the Lacrosse accessories at about $10, then the price for the Maha charger is $57 (with shipping) / $30 (free shipping) = 190%. I'm willing to pay nearly double for a charger if I'm sure I'll like it a lot better, but on the surface it seems that there are both pluses and minuses to going for the Maha. So maybe I'd like it better, maybe not?

Is there a clear advantage to either charger for servicing LSD batteries?

thanks!

 

[funkychateau]

It will quickly figure out charged cells are charged, and switch to discharge mode.

The charge current is anywhere from 200mA to 1.8A, and the discharge current is half of whatever charge current you select in that range.

I don't recall the exact voltage cutoff, but it's .9x

TTA showed a link in his response to a charger thread, and I looked at the PDF manual link for this model. It appears that if I use the "discharge" mode, then I can place a battery charged elsewhere (even if the "other" charge source did not completely fill the battery) and measure the discharge capacity. But, I'd have to sit and wait for the number, because it immediately starts recharging and generating a "charge capacity" number, which is different. Does that jive with your experience?

 

[funkychateau]

Not exactly.

---snip---
Charge    Current    : 200mA, 500mA, 700mA, 1000mA, 1500mA*, 1800mA* (*limit 2 channels)
Discharge Current    : 100mA, 250mA, 350mA,  500mA,    N/A,     N/A  (Charge Current/2)
Trickle   Current    :  10mA,  25mA,  35mA,   50mA,   75mA*,   90mA* (Charge Current/20)

TTA's NiMH/NiCD Battery Charger Specifications Thread: La Crosse BC-900

Thanks! I don't know why, but that thread did not show up when I searched for BC-900.

In fact, no results were returned when using "search this forum" for "BC-900". That's why I started my own thread.

 

[Mr Happy]

Is there a clear advantage to either charger for servicing LSD batteries?

Good things about the C9000 are the flexibility to program each slot individually and separately without restriction; the large spacing between slots making it easy to insert and remove cells, and to help keep them cool; the ability to charge 4 cells at 2 amps each without overheating; the conditioning or break-in mode; the general build quality.

It is very easy to use; I find it a doddle. Reading the manual gives a false idea of it being complicated.

On the down side, the cycling of the display between slots is a minor inconvenience, but only a very minor one. You can always use the slot key to jump to the slot you are interested in. It is quite fussy about cell quality. It may sometimes refuse very old or poor cells for charging, and in the discharge mode poor cells may sometimes drop in voltage and terminate prematurely. Another way of looking at this is that the charger shows up crap cells very clearly.

On balance I like mine a lot and think it is worth the money. Many C9000 owners find their charger in use constantly without a rest.

 

[funkychateau]

Good things about the C9000 are the flexibility to program each slot individually and separately without restriction; the large spacing between slots making it easy to insert and remove cells, and to help keep them cool; the ability to charge 4 cells at 2 amps each without overheating; the conditioning or break-in mode; the general build quality.

It is very easy to use; I find it a doddle. Reading the manual gives a false idea of it being complicated.

On the down side, the cycling of the display between slots is a minor inconvenience, but only a very minor one. You can always use the slot key to jump to the slot you are interested in. It is quite fussy about cell quality. It may sometimes refuse very old or poor cells for charging, and in the discharge mode poor cells may sometimes drop in voltage and terminate prematurely. Another way of looking at this is that the charger shows up crap cells very clearly.

On balance I like mine a lot and think it is worth the money. Many C9000 owners find their charger in use constantly without a rest.

Thanks for the accolades - it seems that if I do decide to pay the extra money, that it will also be a good charger.

BTW - Did I read somewhere (another thread?) that the C9000 has a high-voltage cutoff that terminates prematurely for Eneloop batteries? I can't find that reference now - hopefully I didn't imagine it?

 

[Mr Happy]

BTW - Did I read somewhere (another thread?) that the C9000 has a high-voltage cutoff that terminates prematurely for Eneloop batteries? I can't find that reference now - hopefully I didn't imagine it?

Not just eneloops, but AAA low self-discharge cells can be a bit sensitive. The C9000 controls the discharge current as a 1 amp load with varying on time, so for instance 100 mA is controlled as 10% on, 90% off. If LSD cells have been stored for a long time without use, or if they have been charged poorly, they can develop a higher than normal internal resistance and may not tolerate the 1 amp discharge pulses. On the occasions when my cells do this, I treat them as being out of condition and I recondition them until they perform better. I've not seen AA cells do this, it is mainly AAA cells due to their small size.

(The discharge termination condition is 0.9 V under load with the later C9000 revisions.)

 

[Marduke]

Not exactly.

---snip---
Charge    Current    : 200mA, 500mA, 700mA, 1000mA, 1500mA*, 1800mA* (*limit 2 channels)
Discharge Current    : 100mA, 250mA, 350mA,  500mA,    N/A,     N/A  (Charge Current/2)
Trickle   Current    :  10mA,  25mA,  35mA,   50mA,   75mA*,   90mA* (Charge Current/20)

TTA's NiMH/NiCD Battery Charger Specifications Thread: La Crosse BC-900

So, was it really necessary to be one of those people who pick apart the grammar of a post while totally ignoring the content?

Of course there are discrete intervals, as there is with absolutely ANY measurement in the universe. There is no such thing as "infinitely variable" anything.

Hence, if you have a problem with my choice of the word "anywhere", take it up with the Oxford English Dictionary....

 

[travelinman]

He probably hates infinitely variable lights :thumbsdow

 

[TakeTheActive]

So, was it really necessary to be one of those people who pick apart the grammar of a post while totally ignoring the content?

Of course there are discrete intervals, as there is with absolutely ANY measurement in the universe. There is no such thing as "infinitely variable" anything.

Hence, if you have a problem with my choice of the word "anywhere", take it up with the Oxford English Dictionary....

IMHO, you VASTLY overreacted to my attempt to simply CLARIFY your statement.

Those of us who (portend to) understand 'this technology' attempt to help others who don't. I view internet posts as 'Database Archives' - something that someone at a future date can GOOGLE and get the 'whole picture'. Since I interpreted your post as 'somewhat inaccurate', I attempted to 'clarify' it.

Thus, to put EVERYTHING into one post:

...The charge current is anywhere from 200mA to 1.8A...

Not exactly.

---snip---
Charge    Current    : 200mA, 500mA, 700mA, 1000mA, 1500mA*, 1800mA* (*limit 2 channels)
Discharge Current    : 100mA, 250mA, 350mA,  500mA,    N/A,     N/A  (Charge Current/2)
Trickle   Current    :  10mA,  25mA,  35mA,   50mA,   75mA*,   90mA* (Charge Current/20)

TTA's NiMH/NiCD Battery Charger Specifications Thread: La Crosse BC-900

In comparison, the Maha MH-C9000 has MANY more settings than the La Crosse BC-900:

---snip---
Charge    Current    : 200mA - 2000mA in 100mA steps
Discharge Current    : 100mA - 1000mA in 100mA steps
Trickle   Current    : Topoff 100mA for 2 hrs; Maintenance 10mA

TTA's NiMH/NiCD Battery Charger Specifications Thread: Maha MH-C9000

Where the BC-900 has FOUR Charge/Discharge settings (tied together by a 2:1 ratio and available on all four channels; TWO more Charge-Only settings are available ONLY on channels 1 and 4), the MH-C9000 has NINETEEN Charge settings and TEN Discharge settings - all independently available, on all four channels. MUCH closer to anywhere to me.

Thus, for someone finding this thread on a GOOGLE SEARCH, I attempt to give them as much accurate, standalone information, in one place, as possible. I wasn't picking apart your grammar.

 

[TakeTheActive]

He probably hates infinitely variable lights :thumbsdow

Nope!

Although the majority of the information here on the CandlePower Forums is about flashlights, I only regularly / daily visit the "Batteries Included" forum, reading mainly about NiCD/NiMH technology.

I have no interest in (any new) flashlights. My 2 Bright Star 2D incandescents and my ~8 Mag 2AA and/or 2 AAA incandescents serve my needs just fine.

 

[travelinman]

Just kidding ya! I too love my AA minimags. I've one with an early led conversion and an IQ switch on it and am considering giving it to my 3 yr old grandson. I'll use silver furnace duct tape to tape the head in place and tighten the IQ switch with a plastic jawed wrench so he can't take it apart and hope he can't destroy it. :mecry:

 

[funkychateau]

Got the Charger, and a Bonus!

Received my charger today, will spend the weekend playing with it.

I've been looking for some cheap "C to D" adapters also, and found them as an unexpected bonus in the LaCrosse BC-9009 kit.

Advertised accessories include "AA to C" and "AA to D" adapters. However, the implementation of the latter is such that you first put your AA cells in the "C" adapter, then put these into the "D" adapter.

Obviously, if you put the "C" adapter into the "D" adapter, you could also put "C" CELLS into the "D" adapter. They should add this to the advertising.

 

[Glasstream15]

I have a C9000. I keep it running most of the time. AA and AAA Eneloop, Hybrid and other non-lsd cells. It is a great unit and worth the money.


JMNSHO &, of course, YMMV