Tenergy Centura D 8000 mAh capacity check

[My2Cents]

This is the start of a 6 month test for Tenergy Centura D 8000 mAh.

This exercise is to find out capacity out of retail package, after each forming charge and what remains after 6 months. This will also show benefit (or not) when forming charge is performed back to back.

Advertised capacity is 8,000 mAh. I did not see any production dates or lot numbers printed on battery label so I don't know how long these batteries have been out on retail shelves. These batteries were purchased May, 2011.

Procedure as follows:
1. Discharge at 1.6A (.2C) until 0.9V.
2. Charge at .8A, until 12,800 (1.6C).
3. Steps 1 and 2 above is repeated 4 times with 1 hour pause in between.
4. After last charge, battery is stored for 6 months then discharge at 1.6A (.2C).

Other notes:
a. Discharge 1 is capacity available out of retail package.
b. Discharge 2, 3 and 4 is capacity after each forming charge.
c. Discharge 5, to be done six months later, will be capacity remaining to verify LSD.
d. Equipment used is BC8DP with its corresponding software for logging.

Summary of time and capacity in mAh (% of 8000) to reach certain voltage below.

Battery A
# + 1.20V ------------- + 1.10V ---------------- + 1.00V ---------------- + End ------------------
1 | 00:00 0000 ( 0.00%) | 0:51:18 1366 ( 17.08%) | 1:08:09 1815 ( 22.69%) | 1:10:28 1875 ( 23.44%)
2 | 43:59 1169 (14.61%) | 5:20:07 8529 (106.61%) | 5:36:06 8956 (111.95%) | 5:40:02 9059 (113.24%)
3 | 47:14 1257 (15.71%) | 5:19:07 8504 (106.30%) | 5:35:22 8937 (111.71%) | 5:39:27 9043 (113.04%)
4 | 47:20 1259 (15.74%) | 5:17:56 8472 (105.90%) | 5:33:55 8897 (111.21%) | 5:38:00 9005 (112.56%)

Battery B
# + 1.20V ------------- + 1.10V ---------------- + 1.00V ---------------- + End ------------------
1 | 00:00 0000 ( 0.00%) | 0:40:02 1067 ( 13.34%) | 1:04:39 1723 ( 21.54%) | 1:07:03 1786 ( 22.33%)
2 | 35:42 0949 (11.86%) | 4:52:18 7789 ( 97.36%) | 5:14:41 8386 (104.83%) | 5:18:48 8494 (106.18%)
3 | 36:35 0972 (12.15%) | 4:52:02 7781 ( 97.26%) | 5:14:13 8372 (104.65%) | 5:18:27 8483 (106.04%)
4 | 38:01 1010 (12.63%) | 4:50:47 7748 ( 96.85%) | 5:12:27 8325 (104.06%) | 5:16:44 8438 (105.48%)

Battery C
# + 1.20V ------------- + 1.10V ---------------- + 1.00V ---------------- + End ------------------
1 | 00:00 0000 ( 0.00%) | 0:50:14 1337 ( 16.71%) | 1:09:00 1837 ( 22.96%) | 1:11:25 1900 ( 23.75%)
2 | 42:19 1125 (14.06%) | 5:15:09 8397 (104.96%) | 5:32:22 8856 (110.70%) | 5:36:32 8965 (112.06%)
3 | 45:06 1200 (15.00%) | 5:15:49 8415 (105.19%) | 5:32:44 8866 (110.83%) | 5:36:51 8975 (112.19%)
4 | 45:59 1224 (15.30%) | 5:14:07 8370 (104.63%) | 5:31:11 8825 (110.31%) | 5:35:18 8933 (111.66%)

Battery D
# + 1.20V ------------- + 1.10V ---------------- + 1.00V ---------------- + End ------------------
1 | 00:00 0000 ( 0.00%) | 0:42:13 1123 ( 14.04%) | 1:02:10 1655 ( 20.69%) | 1:04:23 1712 ( 21.40%)
2 | 38:33 1024 (12.80%) | 4:51:59 7780 ( 97.25%) | 5:09:41 8251 (103.14%) | 5:13:30 8351 (104.39%)
3 | 41:02 1090 (13.63%) | 4:52:31 7793 ( 97.41%) | 5:09:56 8258 (103.23%) | 5:13:51 8361 (104.51%)
4 | 42:07 1119 (13.99%) | 4:51:35 7769 ( 97.11%) | 5:08:48 8228 (102.85%) | 5:12:46 8332 (104.15%)

Summary of discharge curve #1 and average of #2, #3 and #4 for each battery.

Battery A details

Battery B details

Battery C details

Battery D details

Other other notes.

Based on Ansmann capacity check and this one, BC8DP.A appears to be reporting discharge number high and/or BC8DP.B low. I started on third LSD brand last night and initial numbers this morning show same pattern. While it is possible that battery that reads high happens to always lands in BCD8DP.A and low in BC8DP.B, it is unlikely that will always be the case. Both chargers already processed a total of 8 batteries and I expect the higher number will be reported on either unit by now (at least once). This is not the case here. I already eliminated battery holder/cradle as a possible cause.

Once third set, now in progress, completes and show same pattern, then I'm going to pause the next capacity checks while I check both chargers. Could be something. Could be nothing. Just want to make sure that numbers being reported are ok. I may have to get the 0720i out of storage and use its discharge numbers to break the tie.

I am hoping that it is just a coincidence since Bantam brand is suppose be known as quality hobby chargers. I already sent email to rcaccessory.com (distributor) who refered the question to bantamtek.com (manufacturer) inquiring about charger being verified/calibrated before leaving the factory. That was about 2 days ago and no reply up to now.

Now back to subject.

 

[LEDAdd1ct]

There are times when you search for many hours to try and find the answer to a question. There are precious few other times when you find exactly what you want with little to no effort. I recently received a Bantam BC8DP, and have been using it to try and revitalize some AccuEvolution LSD "D" batteries, by discharging them and then recharging them. However, I have heard that the Tenergy Centura LSD "D" cells may be a viable alternative. First page on Google, and what do you know: a CPF'er with the same question and the same charger!

I will be subscribing to this thread! I have a couple questions:

1) I would rather not stand there and manually program in the discharge/charge cycles. My2Cents, how do I tell the BC8DP how many cycles to perform?

2) What type of charge setting are you using?

Also, you might want to edit your thread title to say

"Tenergy Centura D 8000 mAh capacity check with BC8DP" so that we know what you are using. Just a suggestion.

I'm excited to see how these cells perform!


🙂


LEDAdd1ct

 

[My2Cents]

#1
There are more setup parameters if you keep turning knob clockwise or counter clockwise. Also some parameters are only available depending on battery type. Cycle will show if you select nimh first and it's way down the setup items so it's a few knob turns before you see it.

#2
Click and hold down knob and charge window will show. for this exercise, I have linear charge, normal discharge. DCHG>CHG is highlighted before pressing start button.

For my capacity check, delta peak and trickle is off, cut-off time 980 minutes and battery capacity as 1.6 of advertised mAh. It has thermal probe and set to 38 celsius, Time is set at 980 (16h20m) instead of 960 (16 hours) because I want charge cycle to hit 1.6C mAh instead of time. However, if cell is defective, mAh entry wrong, or very under capacity, then cell will heat up, exceed cut-off temperature and stop. Reported charge mAh will be less than 1.6C in this case.

Thank you for suggestion, however, equipment is mentioned under 'other notes'.

 

[LEDAdd1ct]

Okay, thanks!

EDIT: ...and, :welcome:

 

[My2Cents]

Thanks... some more items I forgot to mention in capacity check earlier.

Waste time (pause) is 60 minutes, charge at .1C, discharge .2C with cut-off at .9V. I include 1V for my capacity check summary since some have 1V while others .9V for capacity numbers. Also a computer case fan (120mm) connected to 6 volt (dc) adapter so there's air movement across the charger and battery since there's none where they're located. It's more like gentle breeze since fan is actually 12 volts. I also use battery holders from MPD (digikey.com) and not RS. Charger power is using AC part so charger is plugged into UPS just in case of power failure.

Good luck on your LSD revitalization.

 

[VladislavS]

Tenergy Centura D 1A discharge by iCharger.

 

[Eric10]

I'm very curious as to the results of your experiment. Based on the date of the first post, it looks like they're ready to be tested. Any chance we can get some results?

 

[My2Cents]

You are correct. How time flies. Feels like yeterday they were in their own retail package. Time put gizmos back in place and test capacity remaining after 6 months in storage. There are other brands so it will be done in that order. Thanks for reminding.

 

[My2Cents]

Capacity remaining after 6 months below.
Included min/max thermometer shows range of 15-26 degrees celsius while in storage.
Note % remaining is based on 8000 mAh, advertised capacity, and not actual, per forming charge at the start.

# + 1.20V --------- + 1.10V --------------- + 1.00V --------------- + End -----------------
A | 00:10 1 (0.01%) | 4:00:18 6403 (80.04%) | 4:38:00 7408 (92.60%) | 4:43:28 7557 (94.46%)
B | 00:04 1 (0.01%) | 3:38:50 5832 (72.90%) | 4:18:08 6880 (86.00%) | 4:23:34 7026 (87.83%)
C | 00:05 1 (0.01%) | 3:54:18 6248 (78.10%) | 4:33:05 7281 (91.01%) | 4:38:32 7425 (92.81%)
D | 00:07 1 (0.01%) | 3:34:14 5709 (71.36%) | 4:13:01 6742 (84.28%) | 4:18:30 6891 (86.14%)

 

[DrewK]

Capacity remaining after 6 months below.

Thanks for the test. The roughly 82% of actual capacity compares favorably to Tenergy's specification of 80% after 6 months.

 

[JudasD]

Is this Bantam charger able to log more than one NiMH battery at a time? I curious how many channels this charger actually is.

Thanks,
JD

 

[My2Cents]

No, this Bantam charger can only process 1 NiMH battery at a time.
You can charge/discharge NiMH in series as a pack but your log will be for that pack.
1st column under "#" is the number of cycles for each battery and not battery count.

 

[JudasD]

ah, this makes sense. Thank you for clarifying that. I am looking for a nice hobby charger but i cant quite decide on what to get. I thought the bantam could do multiple cells individually which had it at the top of my list initially.
Back to square-one i suppose.

Thanks again,
JD

 

[jayflash]

LEDAdd1ct, what were your results with the AccuEvo's? Did they need restoring from lack of frequent use, storage, or under-performing? I've got the D & C size Accu's and have read of various experiences from different posters about this brand.

Is the advantage of using the Bantam its ability to slowly charge for a programmed time and flexibility in setting rates? What's the going price? Thanks.

 

[LEDAdd1ct]

Hi, jay. After going through my cells (not all of them...have too many!) and discharging and recharging them, I decided I would rather not bother. I use them infrequently, and I realized that since I never fully broke them in when I first received them, I wouldn't know how accurate my tests are. They may be fully usable with some cycling, but I didn't feel like sitting down and going through twelve of them (eight of them AccuPower).

I threw them with my lanterns in my sale on the MP for someone else to play with as a free extra.

I am sorry I cannot be of more help. :-(

I am gravitating toward lithium based chemistries where it is easier to see how full a cell is by its voltage/how that voltage holds under load.

With respect to the Bantam, it is awesome at picking the settings you want for charging and discharging, or just leaving it alone to do cycling on a cell. I believe it has a USB out, though I never tried it (well, not yet, anyway). Here are the full specs:

Link

That is a link to the manufacturer, Bantam. You will find a detailed PDF with even more specs, right at the top of the page.

With respect to price, I never pay full price for anything, and prefer to wait patiently for a killer deal. I think I paid about $160 or $170 for mine.

I am sorry I could not be of more help with the cells, but I can definitely recommend the charger if you are going to use it often. When house cleaning two days ago, I packed the Bantam and accessories in its box and put it aside. I will use it, but not often enough to have it out and ready to go.

 

[jayflash]

Thanks for the Bantam link, LED, no problem re, the Accu's; I'm keeping records of mine and will retest as they age.