Maxpedition AGR/2        
Page 1 of 16 1234567811 ... LastLast
Results 1 to 30 of 465

Thread: Test/Review of Charger Opus BT-C3100 V2.1

  1. #1
    HKJ's Avatar
    Join Date
    Mar 2008
    Location
    Copenhagen, Denmark
    Posts
    8,535

    Default Test/Review of Charger Opus BT-C3100 V2.1

    Charger Opus BT-C3100 V2.1

    This is the 3. review of the BT-C3100. Many pictures and text is reused from the first two reviews, but all curves and measurements are new.
    This charger briefly shows "2.1" in the display when power is connected.

    First review with version 1 software
    Update with version 2.0 software





    This charger is a analyzing LiIon and NiMH charger, this means the charger can both charge and discharge while measuring. The total number of function is large and this means the technical section in this review is very large.
    Note: The top picture is courtesy of Gearbest and is the actual production version of the charger with the Opus logo present.




    I got the charger in a retail box, but the box is without any brand name.



    The only accessory I got was a power supply and a manual. It is a EU version, with universal voltage 100-240VAC 50/60Hz and delivers 12V 3A.



    When the charger is turned on, it displays test where all the text can be seen.
    When startup is finished it is possible to select mode:

    • CHARGE: Charge battery with 200 to 1000 (2000) mA.
    • DISCHARGE: Discharge battery with 200 to 1000 mA (700 for NiMH).
    • DISCHARGE REFRESH: Discharge and charge the battery 3 times.
    • CHARGE TEST: Charge, discharge and charge the battery, show how much current was discharged.
    • QUICK TEST: Measure the internal resistance of the battery.


    When display is flashing it is possible to select mode and current.
    Using the slot button it is possible to reselect a slot and change parameters for it, also when charger is working.
    When putting multiple batteries in the charger at the same time, it is possible to select mode and current simultaneous for all of them (Very nice).

    When charging or discharging it is possible to use the DISPLAY button to select between V, mA and mAh.
    The display button can also be used when the charge/discharge is finished, but the charger will change back to "full" display rather quickly.



    Here is an example where I have selected different functions for each slot.



    Each time a button is pressed, the light turns on for a 20 seconds.
    The FULL and NULL message can also be seen.



    The charger uses an external 12 volt power supply at 3A.
    It has a fan, this is necessary to handle all four channels at full power.
    It starts slowly when needed, this makes it much less annoying.



    The charger uses the classical slider construction to handle most battery sizes. The slider works smoothly and can handle sizes from 32 mm to 72.5 mm.



    A couple of different NiMH batteries in the charger.



    And some LiIon batteries.

    Using only slot #1 and/or #4, the maximum charge current is 2000mA.
    In all other cases the maximum charge current is 1000mA.
    The maximum discharge current is always 1000mA for LiIon and 700mA for NiMH.

    Charge currents: 200, 300, 500, 700, 1000, 1500, 2000
    Discharge currents: 200, 300, 500, 700, (1000)








    The charger can easily handle 70 mm long batteries including flat top cells.
    It is recommended to charge smaller batteries in the two center slots.
    The charger has an internal switch marked with 3.7V, 4.20V and 4.35V. I have not tested this switch, because it is internal, but it might be possible to charge other LiIon chemistries.



    Measurements


    • The LCD background light turns off 20 seconds after the last keypress.
    • It Will discharge LiIon batteries with up to 4.1mA when not charging.
    • Power cycling will restart charging.
    • Reinsertion of batteries will restart last mode selected.
    • LiIon charging will restart if the voltage drops to 4.1V
    • When batteries are put in and no buttons is pressed a 0.5A charge will start.
    • Voltage is measured with current off and is within 0.01 volt.
    • Voltage display is updated once every 30 seconds.
    • When charger is powered on it always starts in charging mode with 0.5A selected.
    • While power is on it remembers last mode selection, but will always start at 0.5A.
    • When not connected to power it will drain about 4.3mA from a LiIon battery and 1.4mA from a NiMH battery.
    • The fan is speed controlled and will slowly increase speed when required.



    CHARGE LiIon batteries



    Charging a 18650 cell at 1A, it is a nice simulated CC/CV curve.
    The display shows 3024mAh 3:41



    The display shows 2713mAh 3:20



    The display shows 2764mAh 3:20



    The 3 other channels look similar.
    The display shows 2803mAh 3:22



    Charging LiIon at very low current does also work fine, but slowly.
    The display shows 2922mAh 16:21



    Because the charger measures voltage with the current off, there will be some overvoltage when charging batteries.
    It does not look that good on this 2600mAh cell, but it ends up with 4.20 volt.
    The display shows 2430mAh 3:59



    A 3400mAh cell looks fine.



    What happens with an old very soft (High Ri) battery? Again the voltage goes to high, but compared to the first version of the charger it is much better.



    Lets reduce the charge current. This did improve the charging considerable, now it looks normal and stays within allowable tolerances.



    Using a newer battery in slot #1 does work fine.



    The 14500 charges fine.
    The display shows 791mAh 2:04



    2A is no problem, the charger reduces current to get a nice simulated CC/CV curve.
    The display shows 2784mAh 2:08



    4 batteries at once with full current. This works fine with the updated software versions
    The display shows 2697mAh 2834mAh 2759mAh 2792mAh (The curve is for the first value).



    Here I tried with the US power supply that showed problems with the V2.0 software. The measurement looks fairly good (Slot #3 & #4 is a bit high).



    Same as above, but I am using an my own power supply, notice the green current scale. The charger is using considerable more than 3A from the power supply in spikes.



    Same curve as above, but I have removed the "DC input current" from the chart. It can be seen that the charger charges perfectly with 1A and there is not any significant difference between this curve and the one above made with the original power supply.



    M1: 35,9C, M2: 37,8C, M3: 37,0C, M4: 34,6C, M5: 34,9C, HS1: 40,8C

    The fan is helping keeping the temperature down, batteries are not that hot.



    M1: 36,0C, M2: 37,6C, M3: 36,8C, M4: 34,3C, M5: 37,3C, HS1: 63,7C

    But something inside the charger is getting warm.



    The charger uses pwm to regulate the charge current. The one above is for 0.2A charge.



    The pulses are longer at 0.5A




    The first version of this charger did have different circuit for slot #1/4 and #2/3, but on the current version they are the same.



    At 2A current the current is on most of the time.



    From power on to start of charge is about 10 seconds, when no buttons is pressed.



    To measure the actual battery voltage the pwm is turned off for about 0.2 seconds every 30 seconds.



    The first version of this charger had some nasty 9A current spikes from the power supply, this made the charger show wrong mAh values when charging.
    In this version the spikes are reduced to 6A and the charge current is stable, this means the charger can measure correctly.



    The power supply can handle the 6A spikes. The voltage drops less than 1 volt.



    DISCHARGE LiIon batteries



    The discharge looks nice. It discharges down to 2.9 volt, it is a good value (In my test I uses 2.8 volt).
    LiIon batteries are usual rated for 2.5, 2.75 or 3.0 volt discharge, the 3.0 volt type might theoretically be damaged, but I have not seen any in my test to 2.8 volt.
    The display shows 2971mAh 2:59





    The other 3 channels looks very similar.
    Display: 2882mAh, 2942mAh, 2960mAh



    With 0.5A the discharge times is double up. Display shows: 2955mAh 5:56



    0.2A discharge also looks fine. Display shows: 2920mAh 14:42.



    With 4 LiIon at 1A the charger needs to get rid of a lot of heat, i.e. the fan runs at full speed. The fan cools enough to handle it.



    M1: 47,7C, M2: 45,9C, M3: 43,2C, M4: 37,2C, M5: 48,7C, M6: 29,3C, HS1: 79,3C

    The resistors for discharging is placed under 3 of the batteries and get fairly hot, this does also warm the batteries.



    The discharge does also uses pwm. The high current is because the charger uses the same resistor bank for NiMH and LiIon.




    The pwm will be adjusted when the battery voltage drops to maintain a constant current.



    DISCHARGE REFRESH LiIon batteries, cycles batteries



    This mode will discharge and charge 3 times. This can be useful for NiMH batteries, but there is really no use for LiIon cells.
    The display shows the values from the last charge: 2851mA 3:24


    CHARGE TEST LiIon batteries, measure capacity



    To test capacity on batteries the test mode is more useful, it will charge the battery, discharge it and charge it again.



    QUICK TEST LiIon batteries, i.e. measuring internal resistance

    I tried with the same LiIon cell in all slots a couple of times:





    The result is average for the 5 values and is supposed to match the +XXmOhm value.
    Generally the result is very good.



    The measuring is done with a short pulse load.



    CHARGE NiMH batteries



    Interesting charger curve, it looks like the charger is using a CC/CV algorithm for NiMH batteries. The charger does a good job with the charging.
    Display shows 1915mAh 2:10
    Also note that the charger uses trickle charging when the main charge is finished, this is not really a good idea for LSD cells.





    The other slots also looks good.



    Maximum charge current.
    Display shows 1939mAh and 1:09



    The temperature raises a bit and then the charger terminates, this is very good.
    Display shows 2192mAh and 2:27



    Even at a low charge current the charger terminates.
    Display shows: 1821mAh 9:12



    A AAA battery does also look fine.
    Display shows 805mAh 2:11



    Due to the termination method the charger is not fast at detecting full batteries, but because it uses a low current most of the time it is not hard on the battery.
    Display shows 75mAh 0:17



    Charging 4 eneloops at the same time looks fine.
    Display shows: 1969mAh 1944mAh 1961mAh 1916mAh



    When I uses my own 12 volt power supply I do not see any high current draw.



    And the charge curve looks fine (Same as above, I have just removed the DC input current trace).



    M1: 37,4C, M2: 38,7C, M3: 37,3C, M4: 35,2C, M5: 35,7C, M6: 25,8C, HS1: 44,1C



    Charging is controlled with pwm for NiMH, but the maximum current is less.




    With 0.5A and 1A the pulses gets longer.



    At 2A charging the current is on most of the time.



    Trickle current is also done with pwm, but uses a very short puls.



    Startup time is the same for NiMH as LiIon.



    The measurement pauses are also the same.



    DISCHARGE NiMH batteries



    The charger does a nice 0.7A discharge and stops just below 0.9 volt.
    Display shows: 1810mAh 2:36



    The 0.2A discharge looks just as fine.
    Display shows: 1814mAh 9:10



    M1: 30,6C, M2: 30,2C, M3: 29,7C, M4: 28,0C, M5: 31,0C, M6: 25,7C, HS1: 38,5C

    Handling the heat from discharging NiMH is easy compared to LiIon.



    Again pwm to regulate the current.



    With full voltage on the battery it is easy to do a 0.7A discharge, when the battery is nearly empty the current will be on most of the time.



    DISCHARGE REFRESH NiMH LiIon batteries, cycles batteries



    The refresh function does 3 cycles, this can be used to restore batteries that have been unused for some time.
    This function takes a day when run at 0.5A on 2000mAh batteries.



    CHARGE TEST NiMH batteries, used to measure capacity



    This function charger, discharges and charges again and is used to measure the capacity of cells.
    Display shows: 1892mAh 2:08


    QUICK TEST NiMH batteries, i.e. measuring internal resistance

    I tried with the same NiMH cell in all slots a couple of times:





    The result is not completely stable, but it does give a good idea about the internal resistance in the battery.



    The measuring is done with a short pulse load.



    CHARGE with both NiMH and LiIon batteries

    With a charger that can do both eneloop and LiIon it is interesting to see if it has any problem doing them at the same time.



    Here I am measuring on the LiIon and it looks very much like a single LiIon, i.e. the NiMH batteries does not affect it.



    A eneloop together with 3 LiIon works fine.


    Testing with 2500 volt and 5000 volt between mains and low volt side on power supply, did not show any safety problems.



    Conclusion

    With this update to the battery analyzer many of the problems has been fixed.
    Generally the peak charge and discharge current for LiIon are a bit high, I would have preferred constant current, instead of the pulsing.
    The user interface is fairly easy to use, but it may take a some time to learn what the different modes do.

    The conclusion must be that it is a good battery analyzer, but for normal charging I will still prefer a charger with non-pulsing CC/CV charging.



    Notes

    When measuring charge current with an oscilloscope I has a 0.1 ohm resistor in series with the battery, this means that the measured currents is lower than reality.

    The charger was supplied by Opus for review.

    Here is an explanation on how I did the above charge curves: How do I test a charger
    My website with battery and charger information: lygte-info.
    More than 1000 reviews of batteries, charges and other stuff.
    Compare 18650 LiIon batteries or smaller (RCR123, 16340, 14500, 10450) LiIon batteries.

  2. #2

    Default Re: Test/Review of Charger Opus BT-C3100 V2.1

    Excellent review, i like it a lot!

    Great job, thank you!!

  3. #3
    Flashaholic* RI Chevy's Avatar
    Join Date
    Aug 2011
    Location
    Ocean State
    Posts
    3,540

    Default Re: Test/Review of Charger Opus BT-C3100 V2.1

    Wow! Very thorough job!
    Thank you Henrik!

  4. #4
    Unenlightened Chloe's Avatar
    Join Date
    Feb 2013
    Location
    受限制
    Posts
    4

    Default Re: Test/Review of Charger Opus BT-C3100 V2.1

    Thanks for the review, HKJ! ^_^

  5. #5

    Default Re: Test/Review of Charger Opus BT-C3100 V2.1

    so...this 2.1 firmware is almost a DEFINITIVE release?

  6. #6

    Default Re: Test/Review of Charger Opus BT-C3100 V2.1

    Quote Originally Posted by realista View Post
    so...this 2.1 firmware is almost a DEFINITIVE release?
    Yes, the v2.1 is already available at gearbest since last week. Use coupon code btc3100 to drop price down to $45

  7. #7

    Default Re: Test/Review of Charger Opus BT-C3100 V2.1

    seems that gearbest is the only one partner who sell this charger at DISCOUNT price. so i think first opus batch are for this site/seller

  8. #8
    Flashaholic* candle lamp's Avatar
    Join Date
    Jun 2010
    Location
    South Korea
    Posts
    1,556

    Default Re: Test/Review of Charger Opus BT-C3100 V2.1

    Thanks a lot for your excellent test review. HKJ!

  9. #9
    Flashaholic* Rosoku Chikara's Avatar
    Join Date
    Dec 2012
    Location
    Niigata, Japan
    Posts
    606

    Default Re: Test/Review of Charger Opus BT-C3100 V2.1

    Quote Originally Posted by HKJ View Post
    ...<Excerpted>



    The charger has an internal switch marked with 3.7V, 4.20V and 4.35V. I have not tested this switch, because it is internal, but it might be possible to charge other LiIon chemistries.

    <highlighted>...
    Thanks for your many in-depth reviews on this forum. But, I have two questions:

    1) How can we find out for sure whether or not this charger can charge LiFePO4?

    2) How hard is it to locate and change this "internal switch."

    Looking forward to your reply. (Or perhaps someone else has already tested this switch?)
    Last edited by Rosoku Chikara; 09-02-2014 at 03:30 PM.
    My avatar photo is that of a small handmade toy boat that propels itself along the water in a realistic "chug-chug" kind of motion, yet is powered entirely by CandlePower. (Japanese children used to make them out of various types of junk, but now they are largely a "lost art.")

  10. #10
    HKJ's Avatar
    Join Date
    Mar 2008
    Location
    Copenhagen, Denmark
    Posts
    8,535

    Default Re: Test/Review of Charger Opus BT-C3100 V2.1

    Quote Originally Posted by Rosoku Chikara View Post
    1) How can be find out for sure whether or not this charger can charge LiFePO4?
    According to some other reviews I have seen it works.

    Quote Originally Posted by Rosoku Chikara View Post
    2) How hard is it to locate and change this "internal switch."


    If you drill a hole in the bottom of the charger you can change the switch from outside.
    My website with battery and charger information: lygte-info.
    More than 1000 reviews of batteries, charges and other stuff.
    Compare 18650 LiIon batteries or smaller (RCR123, 16340, 14500, 10450) LiIon batteries.

  11. #11
    Flashaholic* Rosoku Chikara's Avatar
    Join Date
    Dec 2012
    Location
    Niigata, Japan
    Posts
    606

    Default Re: Test/Review of Charger Opus BT-C3100 V2.1

    Quote Originally Posted by HKJ View Post
    ...According to some other reviews I have seen it works...<snip>
    Thanks for your very prompt reply. I am interested in a multi-chemistry charger, but I need LiFePO4.

    This Opus BT-C3100 V2.1 may be the best solution available today. (Am I correct?)
    My avatar photo is that of a small handmade toy boat that propels itself along the water in a realistic "chug-chug" kind of motion, yet is powered entirely by CandlePower. (Japanese children used to make them out of various types of junk, but now they are largely a "lost art.")

  12. #12
    HKJ's Avatar
    Join Date
    Mar 2008
    Location
    Copenhagen, Denmark
    Posts
    8,535

    Default Re: Test/Review of Charger Opus BT-C3100 V2.1

    Quote Originally Posted by Rosoku Chikara View Post
    Thanks for your very prompt reply. I am interested in a multi-chemistry charger, but I need LiFePO4.

    This Opus BT-C3100 V2.1 may be the best solution available today. (Am I correct?)
    I do not really like the internal switch, if it is supposed to be used it must be external.

    There are some cheap chargers that can do NiMH + LiIon 3.6/4.2 volt. I am testing one now, but I have not looked at the result yet.
    For handling LiIon with different voltage, Xtar has some very good chargers (VP2 & SP1).
    My website with battery and charger information: lygte-info.
    More than 1000 reviews of batteries, charges and other stuff.
    Compare 18650 LiIon batteries or smaller (RCR123, 16340, 14500, 10450) LiIon batteries.

  13. #13
    Flashaholic* Rosoku Chikara's Avatar
    Join Date
    Dec 2012
    Location
    Niigata, Japan
    Posts
    606

    Default Re: Test/Review of Charger Opus BT-C3100 V2.1

    Thanks again for your many excellent reviews, and continuing good advice.

    I have already looked at your reviews of both the Xtar VP2 and SP1. But, as you say, they do not charge NiMH.

    Most of my devices use AAA or AA Ni-MH. I have recently purchased some 10440 and 14500 LiFePO4 which I am now using in certain applications that can safely accept and benefit from the higher voltage. So, I am interested in a good (acceptable) charger that can charge both NiMH and LiFePO4.

    I already have a Maha C9000 for NiMH, but I think it would be most convenient if any new charger I purchase could charge both chemistries. I also like the fact that this Opus C3100 V2 is an "analyzer" similar to the Maha C9000, not just a charger.

    (While it would be nice to know that -if I ever needed to- I could charge other types of LiIon cells, at this point in time, I have no need and no particular interest in the other LiIon chemistries. So, in my particular case, I would probably switch the internal switch to 3.7V and just leave it there.)

    Anyway, I am still "just looking." So, I will keep checking your reviews for something better than this Opus C3100 V2.
    Last edited by Rosoku Chikara; 09-02-2014 at 03:34 PM.
    My avatar photo is that of a small handmade toy boat that propels itself along the water in a realistic "chug-chug" kind of motion, yet is powered entirely by CandlePower. (Japanese children used to make them out of various types of junk, but now they are largely a "lost art.")

  14. #14

    Default Re: Test/Review of Charger Opus BT-C3100 V2.1

    This charger's price has just been reduced to $42. ( use coupon code OP3100). They have just sold the 100th unit, hence, the reduction.
    Last edited by tatasal; 09-03-2014 at 02:54 AM.

  15. #15

    Default Re: Test/Review of Charger Opus BT-C3100 V2.1

    Thanks for the review. As a user of NiMH, Li-Ion, and LiFePO4 I am intrigued by 'the switch' and am looking forward to more reviews/testing of this charger... would be nice to have a proper smart charger to complement my C9000, although I've had no problems with my i4 v2 or Surefire LiFePO4 charger.

  16. #16

    Thumbs up Re: Test/Review of Charger Opus BT-C3100 V2.1

    Quote Originally Posted by tatasal View Post
    This charger's price has just been reduced to $42. ( use coupon code OP3100). They have just sold the 100th unit, hence, the reduction.
    Thank you for that heads-up -
    seems like a very good charger to try out at this coupon price.

    The only thing that may prevent it from being an ideal charger is being only capable of 1 Amp charge for 4x NiMH.

    I only really needed this since the advent of the Eneloop XX @ ~2450mAh
    and their re-badged clones - Duracell Ion Core AA (link to thread) -
    where 0.5C would require 1200-1225mA charge current
    (I do realize the Opus 3100 is capable of up to 2Amp charge current but this is only for to 1-2 NiMH)

    Does anyone know if the manual is available on-line please?
    or be willing to scan and post it?

    Thanks

  17. #17
    Flashaholic* Wiggle's Avatar
    Join Date
    Sep 2008
    Location
    Halifax, NS
    Posts
    1,275

    Default Re: Test/Review of Charger Opus BT-C3100 V2.1

    Just got my Opus 2.1, liking it so far. I am thankful for the analyzing capability of this charger, it will let me sort and trim down my battery collection once I am able to quantify the performance/capacity of my cells a bit. My Nitecore I4 sadly croaked a few months back and this one is definitely a step up (though the I4 was simple and worked well before failing). I may still use my WF139 charger which has faithfully served me for years and always terminates correctly but this one will get some serious use too.
    Last edited by Wiggle; 09-10-2014 at 07:30 AM.

  18. #18
    Flashaholic* subwoofer's Avatar
    Join Date
    May 2010
    Location
    Hove, UK
    Posts
    2,334

    Default Re: Test/Review of Charger Opus BT-C3100 V2.1

    Fantastic review and very thorough testing. Many thanks HKJ

    I'm assuming that the firmware is not upgradable by the user? (in which case it is important to buy the V2.1)
    Last edited by subwoofer; 09-10-2014 at 08:00 AM.
    Tactical Reviews by Subwoofer
    Latest Reviews - @TacticalReviews and Facebook
    CandlePower Forums "Trusted Product Tester / Reviewer"

  19. #19
    Flashaholic* Wiggle's Avatar
    Join Date
    Sep 2008
    Location
    Halifax, NS
    Posts
    1,275

    Default Re: Test/Review of Charger Opus BT-C3100 V2.1

    Quote Originally Posted by HKJ View Post



    Same as above, but I am using an my own power supply, notice the green current scale. The charger is using considerable more than 3A from the power supply in spikes.



    Same curve as above, but I have removed the "DC input current" from the chart. It can be seen that the charger charges perfectly with 1A and there is not any significant difference between this curve and the one above made with the original power supply.
    Am I correct in assuming that this means that even with a limited current of 1A on supply side the charger can still correctly charge at 4 x 1A? Just a little confused cause it seems like more energy is going into the batteries than is being pulled from the power supply (1000 mA x 12V is less than 1000 mA * 4 * 3.7V).

  20. #20
    HKJ's Avatar
    Join Date
    Mar 2008
    Location
    Copenhagen, Denmark
    Posts
    8,535

    Default Re: Test/Review of Charger Opus BT-C3100 V2.1

    Quote Originally Posted by Wiggle View Post
    Am I correct in assuming that this means that even with a limited current of 1A on supply side the charger can still correctly charge at 4 x 1A? Just a little confused cause it seems like more energy is going into the batteries than is being pulled from the power supply (1000 mA x 12V is less than 1000 mA * 4 * 3.7V).
    No.
    The supplied power supply is 3A and doing an average of my measured current for the first 15 minutes gives 2.2A.
    With NiMH the average is 1.3A
    My website with battery and charger information: lygte-info.
    More than 1000 reviews of batteries, charges and other stuff.
    Compare 18650 LiIon batteries or smaller (RCR123, 16340, 14500, 10450) LiIon batteries.

  21. #21
    Flashaholic* Wiggle's Avatar
    Join Date
    Sep 2008
    Location
    Halifax, NS
    Posts
    1,275

    Default Re: Test/Review of Charger Opus BT-C3100 V2.1

    Ah gotcha, thanks for the clarification.

  22. #22
    Flashaholic* Wiggle's Avatar
    Join Date
    Sep 2008
    Location
    Halifax, NS
    Posts
    1,275

    Default Re: Test/Review of Charger Opus BT-C3100 V2.1

    The analyzing features are nice, I have already been able to pick out one bad cell (just a cheap Trustfire so no big shock here) and confirmed that even after 20 months use in my EDC (with lots of 500 lumen burst mode use) my Zebralight 14500 cell still has about 760 mAh of capacity, not too far down off the rated 880 mAh for that much use.
    Last edited by Wiggle; 09-10-2014 at 10:02 AM.

  23. #23

    Exclamation Re: Test/Review of Charger Opus BT-C3100 V2.1

    Quote Originally Posted by HKJ View Post
    No.
    The supplied power supply is 3A and doing an average of my measured current for the first 15 minutes gives 2.2A.
    With NiMH the average is 1.3A
    Thanks for the measurements -
    here's a more simple minded explanation -
    4x NiMH AA @ 1Amp charge current each is 4x 1.2V x 1A = 4.8watts
    (to perhaps 6watts max - these are worst possible cases where if it were theoretically possible for the cells to start at 0 Volts!!!)

    The power supply is rated for 3Amps BUT @ 12Volts = 3Ax12V = 36watts
    so the power supply should be more than adequate to charge 4x NiMH AA batteries.

    I would have thought it was adequate for 2Amps for 4x NiMH AA -
    but seems from HKJ's figures it probably would not for the first 15mins -
    but it ought to be able to support a charge current of 1.2+Amps for 4x NiMH AA.

  24. #24
    HKJ's Avatar
    Join Date
    Mar 2008
    Location
    Copenhagen, Denmark
    Posts
    8,535

    Default Re: Test/Review of Charger Opus BT-C3100 V2.1

    Quote Originally Posted by UnknownVT View Post
    Thanks for the measurements -
    here's a more simple minded explanation -
    4x NiMH AA @ 1Amp charge current each is 4x 1.2V x 1A = 4.8watts
    (to perhaps 6watts max - these are worst possible cases where if it were theoretically possible for the cells to start at 0 Volts!!!)

    The power supply is rated for 3Amps BUT @ 12Volts = 3Ax12V = 36watts
    so the power supply should be more than adequate to charge 4x NiMH AA batteries.

    I would have thought it was adequate for 2Amps for 4x NiMH AA -
    but seems from HKJ's figures it probably would not for the first 15mins -
    but it ought to be able to support a charge current of 1.2+Amps for 4x NiMH AA.
    You did not read the 3. line in my reply, that contains the current reading for NiMH.

    When charging NiMH the voltage is up to 1.5 volt, i.e. you are charging 6 watt to charge.into the batteries, not 4.8 watt.

    Also note that my current calculation was for the first 15 minutes, but the highest current will be drawn just before the charger starts reducing the charge current, at least if the converter inside the charger has the same efficiency.

    I could easily add a "Average DC current" trace, but I believe that there is already to many traces in the chart.
    My website with battery and charger information: lygte-info.
    More than 1000 reviews of batteries, charges and other stuff.
    Compare 18650 LiIon batteries or smaller (RCR123, 16340, 14500, 10450) LiIon batteries.

  25. #25

    Question Re: Test/Review of Charger Opus BT-C3100 V2.1

    Quote Originally Posted by HKJ View Post
    You did not read the 3. line in my reply, that contains the current reading for NiMH.

    When charging NiMH the voltage is up to 1.5 volt, i.e. you are charging 6 watt to charge.into the batteries, not 4.8 watt.

    Also note that my current calculation was for the first 15 minutes, but the highest current will be drawn just before the charger starts reducing the charge current, at least if the converter inside the charger has the same efficiency.

    I could easily add a "Average DC current" trace, but I believe that there is already to many traces in the chart.
    HKJ,

    Thanks for the response -
    yes, I did read your 3rd line in you very helpful reply, thanks -

    perhaps you didn't see the last para of my post?
    stating where I "thought" the power supply should be able to support charging 4x NiMH AA @ 2A -

    Quote Originally Posted by UnknownVT View Post
    I would have thought it was adequate for 2Amps for 4x NiMH AA -
    but seems from HKJ's figures it probably would not for the first 15mins -
    but it ought to be able to support a charge current of 1.2+Amps for 4x NiMH AA.
    re: 4.8watts vs 6watts
    Quote Originally Posted by UnknownVT View Post
    (to perhaps 6watts max -
    The point was the power supply is rated 36watts
    and the max charge for 4x NiMH AA @ 1A is only 6watts.

    I just checked my Maha/PowerEx C9000 power supply and it is only rated for 2A @ 12volts - and yet the C9000 can charge 4x NiMH @ 2A.

    Thank you for your very helpful thorough reviews and posts.

  26. #26
    HKJ's Avatar
    Join Date
    Mar 2008
    Location
    Copenhagen, Denmark
    Posts
    8,535

    Default Re: Test/Review of Charger Opus BT-C3100 V2.1

    The maximum power draw from the supply is not when the batteries has 0 volt, but just before the charger stops or reduces current.
    0 volt at X amperes only requires -> 0*X -> 0 watt.

    The charger has more than enough power to charge at NiMH 2A. It is probably done the way it is to make NiMH and LiIon as equal as possible.
    My website with battery and charger information: lygte-info.
    More than 1000 reviews of batteries, charges and other stuff.
    Compare 18650 LiIon batteries or smaller (RCR123, 16340, 14500, 10450) LiIon batteries.

  27. #27

    Question Re: Test/Review of Charger Opus BT-C3100 V2.1

    Quote Originally Posted by HKJ View Post
    The maximum power draw from the supply is not when the batteries has 0 volt, but just before the charger stops or reduces current.
    0 volt at X amperes only requires -> 0*X -> 0 watt.

    The charger has more than enough power to charge at NiMH 2A. It is probably done the way it is to make NiMH and LiIon as equal as possible.
    Thanks for the explanation -
    perhaps I ought to explain my 0volt comment -
    I was thinking in terms of the difference between a "full" battery and one that was "empty" -
    I used a theoretical empty battery as 0volts (which I know is not physically possible)

    Would you please explain why the current draw on charger power supply is 2.2A for the first 15minutes ?

    Thanks

  28. #28
    HKJ's Avatar
    Join Date
    Mar 2008
    Location
    Copenhagen, Denmark
    Posts
    8,535

    Default Re: Test/Review of Charger Opus BT-C3100 V2.1

    Quote Originally Posted by UnknownVT View Post
    perhaps I ought to explain my 0volt comment -
    I was thinking in terms of the difference between a "full" battery and one that was "empty" -
    I used a theoretical empty battery as 0volts (which I know is not physically possible)
    But as I written before: The maximum power draw is when the battery is nearly full.

    Quote Originally Posted by UnknownVT View Post
    Would you please explain why the current draw on charger power supply is 2.2A for the first 15minutes ?
    I did an average of the first 1000 data point in my log file, that is the reason that the value is for the first 15 minutes (I log one record each 0.9 second). I could have done the average anywhere in the logfile, but the beginning is easy to find. The end is not usable, except if I want the idle current.

    The charger is charging with 1A at about 3.5 volt (LiIon see charge curve in review), this means the charge power is 1A*3.5V*4 -> 14 watt, but it uses 2.2*12 -> 26.4 watt from the power supply
    My website with battery and charger information: lygte-info.
    More than 1000 reviews of batteries, charges and other stuff.
    Compare 18650 LiIon batteries or smaller (RCR123, 16340, 14500, 10450) LiIon batteries.

  29. #29

    Question Re: Test/Review of Charger Opus BT-C3100 V2.1

    Quote Originally Posted by HKJ View Post
    But as I written before: The maximum power draw is when the battery is nearly full.
    Thank you for that, I understand.

    Quote Originally Posted by HKJ View Post
    I did an average of the first 1000 data point in my log file, that is the reason that the value is for the first 15 minutes (I log one record each 0.9 second). I could have done the average anywhere in the logfile, but the beginning is easy to find. The end is not usable, except if I want the idle current.

    The charger is charging with 1A at about 3.5 volt (LiIon see charge curve in review), this means the charge power is 1A*3.5V*4 -> 14 watt, but it uses 2.2*12 -> 26.4 watt from the power supply
    I can see that, it is for LiIon?

    For 4x NiMH AA is the initial current draw different, please?

    Thanks

  30. #30
    HKJ's Avatar
    Join Date
    Mar 2008
    Location
    Copenhagen, Denmark
    Posts
    8,535

    Default Re: Test/Review of Charger Opus BT-C3100 V2.1

    Quote Originally Posted by UnknownVT View Post
    For 4x NiMH AA is the initial current draw different, please?
    That was the 3. line I was referring to before, the current draw is 1.3A.
    My website with battery and charger information: lygte-info.
    More than 1000 reviews of batteries, charges and other stuff.
    Compare 18650 LiIon batteries or smaller (RCR123, 16340, 14500, 10450) LiIon batteries.

Page 1 of 16 1234567811 ... LastLast

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •