TTA's NiMH/NiCD Battery Charger Specifications Discussion Thread

TakeTheActive

Enlightened
Joined
Dec 16, 2008
Messages
830
Location
Central NJ, USA
Folks that have been members of an active forum (like CPF's Batteries Included, for example) for years and log on at least daily to keep up with the new posts generally don't realize the OVERWHELMING amount of information that gets incrementally stored in the Archives. There is WAY TOO MUCH information for any Newbie to be able to first LOCATE, then absorb without the kind of time investment that I've made (several hours per week since ~Thanksgiving 2008).

Unfortunately, there's no particular 'rhyme-or-reason' as to where a 'gem' of theory, or a LINK to a PDF, will be located. With the 'poor' vBulletin SEARCH function (I use GOOGLE w/Advanced Search Operators most of the time) and the vast number of messages, you certainly can't expect the good stuff to just 'pop to the top'. Nope, it takes time to locate. And then, once you find it, try to find it again, weeks or months later, without investing another chunk of time.

That's why I'm sharing what I deem to be some of the "Best Answers..." that I found, so far, and am promoting it via my Sig Line. I'd rather POINT to an excellent, COMPLETE archived answer than repeatedly provide 'bits-n-pieces' of the answer over the course of several replies.

Since my "Best Answers..." thread seems to be finally gaining some traction (over 300 views, lately averaging ~10/day, received my FIRST 'Thank You'...), I'm now starting another 'unique' thread that I've been working on for a few weeks.

Besides theory and PDF LINKs, another item that I usually have repeat questions on is "NiMH/NiCD Battery Charger Specifications". COMPLETE specifications for chargers are (usually) not available. Most of the data is here via LINKs to manufacturer's sites or posts, but, 'juicy tidbits' from CPF members are spread all over. When I followed a LINK a few weeks ago to the Energizer Duo (CHUSB) Datasheet, I liked the layout of the specifications. I took that layout into Notepad and customized it a bit. The current / final result is below for 4 chargers.

My plan is to create 2 threads:
  1. TTA's NiMH/NiCD Battery Charger Specifications Thread: for DATA ONLY!
    - Post #1 will be an alphabetical List of LINKs to each following post.
    - Posts #2-N will be the charger specifications, individually submitted and maintained by CPF members, in the requested format. Do not ADD or DELETE any rows. If your charger doesn't have a certain feature, put "N/A" on that line. If you feel that I left out an important feature, suggest it in this thread.
    .
  2. TTA's NiMH/NiCD Battery Charger Specifications Discussion Thread (THIS thread): for suggestions, corrections, questions, etc...
I would appreciate it if the CPF members reading this thread would CHECK my data against theirs and COMMENT on the layout here - NOT in the 'Data Only' Thread.

I'll continue adding specs as I find them. And I ask other CPF members, please submit the specs of YOUR chargers in the requested format of the blank template below. Use a monospace text editor, like Notepad, to align your data before adding it to the DATA ONLY thread.

Thanks, in advance, for everyone's participation and cooperation!

Format:

---FORMAT BEGIN---
Model: Place Model Name here
Code:
Input Voltage        : 
Channels             : 
Cells                : 
Charge Status        : 
Shutoff Mechanism    : 
-DeltaV              : 
DT                   : 
Max Charge Voltage   : 
Max Charge Temp      : 
Max Charge Time      : 
Max Charge mAh       : 
Min Discharge Voltage: 
Charge    Current    : 
Discharge Current    : 
Trickle   Current    :
Place LINK to manual here
---FORMAT END---

UPDATE(s):
  • 01/30/2009
    - Added: Input Voltage, Cell Chemistry and Charger Status to the template
  • 01/28/2009
    - 4 initial submissions moved to DATA ONLY thread
    - Blank data submission form template added
 
Last edited:
Hi, TTA

I think this is a great idea. I've used your link to your archive of articles many times and find it invaluable. As I'm trying to get back up to speed in basic electronics and learn more about batteries, chargers, etc., having a resource in an easy to use format is a great help.

You're right about 'gems' being buried. That's just the way they develop, though, with random threads here and there and pieces of information coming out as people talk about various subjects on here. Having an organized reference makes it easier to find these gems.


I think the charger reference would be useful. I also think the same thing done with rechargeable batteries, summarized in a nice format like you have for the chargers would be great, too!

Keep up the good work!
:goodjob:
 
Good idea for a thread.

On the subject of:
TakeTheActive said:
Model: La Crosse BC-900
Code:
Max Charge Voltage   : 1.53V (observed by TTA)

I submit the following for your viewing pleasure:

IMGP0267.jpg


I got a NiCd cell from my landscape lights up to 1.71v in this puppy. Charger firmware is v33.

So what does this mean? I don't know. But I did in fact get a cell to rise way above what seems right and good. It makes me wonder if there is a max voltage at all in the BC-900.
 
Last edited:
I have an ancient nicd AA cell that has about 90mAh capacity left out of original 700mAh, has vented a couple of times, keeps the charge for maybe a minute or two.

Hit it with 1.8A from BC-900. Voltage shot up to 1.71 initially, then went down to 1.65 after awhile. Current was still at 1800, so I guess it missed termination. At >10C not that surprising, I guess :)
 
...I think this is a great idea...
Good idea for a thread...
Thanks! :)

...I've used your link to your archive of articles many times and find it invaluable. As I'm trying to get back up to speed in basic electronics and learn more about batteries, chargers, etc., having a resource in an easy to use format is a great help.

You're right about 'gems' being buried. That's just the way they develop, though, with random threads here and there and pieces of information coming out as people talk about various subjects on here. Having an organized reference makes it easier to find these gems...
[BROKEN RECORD MODE ON]

Reading daily, for several hours per week, since ~Thanksgiving 2008, I kept coming across:
  • Terms that I was unfamiliar with
  • Theories / methodologies that I was unaware of
  • LINKs to various manufacturer's technical data
  • LINKs to various manufacturer's manuals
  • etc...
Thread Subscriptions couldn't handle the task - bookmarks were needed. And, I figured, if *I* didn't know about "all this *GREAT* stuff", maybe others didn't either... ;)

[BROKEN RECORD MODE OFF]

...I think the charger reference would be useful...
:anyone: :help: VOLUNTEERS? :help: :anyone:

...I also think the same thing done with rechargeable batteries, summarized in a nice format like you have for the chargers would be great, too!
Let's say EVERYONE who's interested start putting together their own list of parameters. In a couple of days, I'll start a new DISCUSSION thread with what I have come up with and we'll work forward from there. :grouphug: Deal?

...Keep up the good work!
:goodjob:
:thanks:
 
La Crosse BC-900 Max Charge Voltage?

...I got a NiCd cell from my landscape lights up to 1.71v in this puppy. Charger firmware is v33.

So what does this mean? I don't know. But I did in fact get a cell to rise way above what seems right and good. It makes me wonder if there is a max voltage at all in the BC-900.
I believe that I saw 1.52VDC posted in the archives (and I originally had that in my spec entry). Then I saw 1.53VDC (with a NiMH) on my BC-900 v33. Now you have 1.71VDC (with a NiCD).

:confused: SilverFox???
 
Not quite a BC900 but anyway,

BC700 v36 with ageing garden light Nicad`s just before termination.

1233191879.jpg

The voltage drops before it terminates, maybe 1.86v isn`t the roof either. Grab some :popcorn: and watch it in this video if you fancy. :)
 
  • Added 3 new fields to the charger specifications template
    .
  • Added 3 new chargers to the DATA ONLY thread
    .
  • Updated the existing chargers data with the 3 new fields
 
i dont know if your listing it, but i think it is very important when listing the "current" it can/does run at, that you also list the ACTUAL current it is still running at reguardless of any cute numbers or the averaging.

if these things are using PWM (pulses) of a specific larger current to do the smaller currents , then that is MUCH different than a charger that is current controlled, or just current limited.

WHY? because that can significantly change how the things react ? Well NOT so much that reason, but because it is LESS knowledge to THINK that something is running at 500ma, when in reality it is running at 1000ma 1/2 of the time. meaning i have always seen it a disservice to say it IS running at 200ma, when it isn't, IF it is really running at 2000ma 1/10th pulses stuff.

the actual rate vrses the averaged rate via pulses, can completly vary something like believing it is charging at a "slow" rate at 200ma, a rate that is within specs for overcharge, when that is not what is happening at all, at 1000ma it is above the rate for overcharge specs (for the usual cell) even though the AVERAGED rate seems to be below it.
when understanding charge rates, and slow charges and stuff, this difference in what is SEEN and said and what is actually occuring, makes all the difference in the world sometimes. and i am not positive all the effects, i am just positive the REALITY should be displayed along with the Fantasy.

also it might be noted (again, just making it a bigger pain in the butt) that many of the rates that are or are not pulsed, are wrong in thier averaging also, they will say a charger that is 250ma, but pauses to check the voltage is charging at 250ma , when it is AVERAGED out to 230-210ma.
so again thier spec sheets leaving out lots of stuff for simplicity, doesnt help out anything. also many averaged displayed rates are just plain wrong, because they screwed up the microprocessor math on the pausing and checking, and close enough was just that, close enough, reguardless of it being enough difference after hours of 10% or more. or again enough to be the difference between in and out of specs, even if the spec sheet and a Meter reading even, says its OUT of spec, it may be IN it. . . ohhh i am sooo confused :)

knowing the actual numbers vrses the percieved numbers is merly a knowlege thing, WHY is it doing this or that IF it is supposed to be charging at this? because it ISNT.

----------------------------------------------------------------------------------------------------------

the max voltage (again) would be another pain in the buttox. Max voltage when the charge is put on it, MUST be high, because of the way they are charging (especially fast) they have to have a large "differential" in the voltages to get the amperage. BUT what the max voltage a cell is allowed to GET TO could be a critical factor in the treatment of a cell that isnt acting like the "book" says it should react. it is also a critical factor when the computer decided to Crash, leaving that being the only final factor in whether it burns your house down or not :)
if i remember right most of these high speed type of computer smart chargers are charging with about a 2Volt potetial.
Some of the chargers having a Max voltage termination or adjustment , built into the charge alogrythm for those special cells which didnt terminate on a v-drop, and also just added in to be much nicer on the cell itself, just a better alogrythm for charging. the max voltage the Battery is allowed to get to.
Then there is also the impedance checking (HIGH) , which if i remember right is about 2+V also, they pound the cell for a few seconds with 2+V at full amp, and see if it goes "loose" on them or if it holds the voltage down via the batterys own resistance.

---------------------------------------------------

the temp probes OWN temperature setting, is one thing, but how hot the BATTERY can actually get can be completly different, some of this stuff the temp probe is so poorly connected , i wonder what the heck the temp probe is supposed to be reading, the air in the charger or the battery :)

-------------------------
and thanks for the Seperate thread for the discussion part, I wouldnt want to mess up your great compilation of data, so i was able to put the noise in here.
why does everything "digital" and computer, and processor, have to become BINARY (on or off) when doing everything, when they went from analog to digital, they lost everything in between :)
 
Last edited:
VidPro,

When you initially posted...
i dont know if your listing it, but i think it is very important when listing the "current" it can/does run at, that you also list the ACTUAL current it is still running at reguardless of any cute numbers or the averaging.

if these things are using PWM (pulses) of a specific larger current to do the smaller currents , then that is MUCH different than a charger that is current controlled, or just current limited...
...I didn't immediately reply because, honestly, I had no answer :confused: - I have never seen the information you requested posted, nor do I own (or know how to use) the equipment to measure it.

I delayed posting because I expected one of the "CPF Gurus" to chime in with some 'words of wisdom' as to whether or not your requests were feasible. :thinking:

IMHO (on this and *MANY* other forums):
  • Technical Discussion threads are GOOD, but infrequent.
  • "LAZY", "I Can't Be Bothered to SEARCH" Discussion threads are BAD, but frequent.
  • Individual DETAILED Technical Results posts are GOOD, but infrequent and don't follow any consistent format.
  • Replies to requests for participation in DETAILED Technical Results post are PRACTICALLY NON-EXISTANT.
  • Most folks treat their forum participation like a meeting at the office 'Water Cooler' / 'Break Room':
    1. Participation peaks Mon-Fri, 9-5.
    2. Most answers are short, usually incomplete.
    3. Their 'TOTAL POST COUNT' is usually HIGH (see #1 and #2).
...and thanks for the Seperate thread for the discussion part, I wouldnt want to mess up your great compilation of data, so i was able to put the noise in here...
Thanks!

I plan to use this same format for other 'Technical Discussion' Threads that I have planned... :)
 
...I didn't immediately reply because, honestly, I had no answer :confused: - I have never seen the information you requested posted, nor do I own (or know how to use) the equipment to measure it.

The pulsing could probably be seen even when measuring current applied to the batteries with a DMM. I think that the PWM frequency would usually be low enough for the DMM to detect current fluctuations. Although it would be much harder to precisely measure the pulse frequency and values.

If you wanted to add such information, my Maha C9000 uses PWM-ed ~2A current for charge and ~1A for discharge.
 
TTA, can you correct the max voltage for the BC900? with mine i have reach 2.07V, don't know what is the limit but for sure it haven't a voltage limit like a charge termination

also the capacity limit is 3.7Ah with no time limit, so it can charge at 3.7Ah at 200mA and at 1.8A



 
Last edited:
...If you wanted to add such information, my Maha C9000 uses PWM-ed ~2A current for charge and ~1A for discharge.
I've noticed that my La Crosse BC-900 can further discharge cells (at the SAME rate) after my Maha MH-C9000 has quit. IIRC, this has something to do with PWM and the C9000 being 'more aggressive'. BUT, AFAICT, most manufactuers don't publish this information *AND* personally I don't feel that most users will understand / utilize it.

It appears that the 'usually VERY vocal' VidPro has been 'away' for the past ~2-3 weeks and hasn't gotten back to this thread yet.

*IF* other members can provide the 'Missing PWM Data' for the majority of the chargers already listed in the thread, I'll be glad to add it. If no one else cares, well then... :rolleyes:

Thanks for the offer. :)
 
I've noticed that my La Crosse BC-900 can further discharge cells (at the SAME rate) after my Maha MH-C9000 has quit. IIRC, this has something to do with PWM and the C9000 being 'more aggressive'. BUT, AFAICT, most manufactuers don't publish this information *AND* personally I don't feel that most users will understand / utilize it.

I remember reading somewhere that both the chargers use PWM for discharge (although for BC-900 it's PWM-ed 500mA and 1000mA for C9000). IIRC the main difference was that C9000s (recent versions) measure under load voltage and BC-900 open circuit. I haven't checked if that's true but if it is, 0.9V cut-off voltage means something completely different for them...
 
TTA, can you correct the max voltage for the BC900? with mine i have reach 2.07V, don't know what is the limit but for sure it haven't a voltage limit like a charge termination...
  1. ...I submit the following for your viewing pleasure:

    IMGP0267.jpg


    I got a NiCd cell from my landscape lights up to 1.71v in this puppy. Charger firmware is v33...
  2. I have an ancient nicd AA cell that has about 90mAh capacity left out of original 700mAh, has vented a couple of times, keeps the charge for maybe a minute or two.

    Hit it with 1.8A from BC-900. Voltage shot up to 1.71 initially, then went down to 1.65 after awhile...
  3. ...BC700 v36 with ageing garden light Nicad`s just before termination.

    1233191879.jpg

    The voltage drops before it terminates, maybe 1.86v isn`t the roof either...
IIRC, the 1.52VDC spec came from a CPF Guru, possibly SilverFox. And, you'll note above, that ALL of the discrepancies noted to-date are from 'Aged' and/or NiCD cells.

Thus, I believe that 1.52VDC is the 'Rule' and somehow these noted 'Exceptions' are tricking the firmware. I edited my OP.

BTW, I recently saw 1.61VDC during a 'Refresh-and-Analyze' cycle of some 'Brand-New' Harbor Freight 700mAh NiCD cells on my MH-C9000 (1.47VDC MAX!). I'm guessing that it was during the 'Top-Off' period. Personally, I won't be too concerned until it happens on a NEW Eneloop-type LSD cell. :)

...also the capacity limit is 3.7Ah...
My manual states the capacity limit is 3000mAh. Perhaps you have a non-USA version with different specifications?

...with no time limit, so it can charge at 3.7Ah at 200mA and at 1.8A...
There MUST be a 'Time Limit' in order to limit the total charge to 3000mAh (3000mAh / Charge Current in mA = Time in Hours):
Code:
Max Charge Time      :  15hr,   6hr, 4.3hr,    3hr,    2hr,   1.6hr  (3000mAh/Charge Current)
Max Charge mAh       : 3000mAh
Charge    Current    : 200mA, 500mA, 700mA, 1000mA, 1500mA*, 1800mA* (*limit 2 channels)

Although I appreciate your photos, I do find it 'difficult to see all the details' unless I go to the site and CLICK on 'Full Size'. Would it be possible for you to re-do them (sometime in the future), without the glare and reflections (i.e. daytime / natural lighting WITHOUT flash *OR* better flash angle)? Thanks!
 
IIRC, the 1.52VDC spec came from a CPF Guru, possibly SilverFox. And, you'll note above, that ALL of the discrepancies noted to-date are from 'Aged' and/or NiCD cells.

Thus, I believe that 1.52VDC is the 'Rule' and somehow these noted 'Exceptions' are tricking the firmware. I edited my OP.

well thats sure, higher voltages come from aged batts (high IR), a new batt can't go at 2V under charge unless you apply a 10C charge ;) btw the charger can't know if you have insert a brand new or a crappy cell, simply the BC900, if have a voltage limit, is over 2.07V

My manual states the capacity limit is 3000mAh. Perhaps you have a non-USA version with different specifications?

i have a usa version, buyed from j.s. burly. the 3.7Ah limit was observed also from other people, try a search, the manual is incorrect, or it take in count the error of the BC900 and the fact that a battery can be slightly overcharged for take a 100% of charge

There MUST be a 'Time Limit' in order to limit the total charge to 3000mAh (3000mAh / Charge Current in mA = Time in Hours)

don't know how it work exactly, but the BC900 haven't a quartz oscillator in fact it have and error of various minutes in a hour. the count of the mAh is a simple moltiplication of the set current and the time passed (don't take in count the pause for the voltage reading like the C9000). maybe it have a time based stop on the 6 charge currents, but due they all arrive at 3.7Ah, i think is simpler to set a stop when the mAh counter reach 3.7Ah. the result don't change

Although I appreciate your photos, I do find it 'difficult to see all the details' unless I go to the site and CLICK on 'Full Size'. Would it be possible for you to re-do them (sometime in the future), without the glare and reflections (i.e. daytime / natural lighting WITHOUT flash *OR* better flash angle)? Thanks!

well i prefer to do not stress so much the charger and batts again, take the pictures as samples, also if they are ugly ;)
 
Top