wptski
Flashlight Enthusiast
Try them at 2A.LuxLuthor said:
Improved Maha C9000…
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wptski
Flashlight Enthusiast
I edited Post#204 with discharges of the 2.3Ah Duracells. Oh yeah, tacoal was correct about the fact that the externally connected cell with no heat from the charger terminated correct, although low! Slot#2 did have the largest overcharge too!
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Hi Tom,
In general, the resistence is a linear one. However, the impedence of a battery might be a nonlinear one. This mean it changes with the current through it. Further, the impedence when changing might be different from the internal resistence when discharging.
Yes, some batteries, the high capacity ones, once stopped on BC-900 when voltage is about 1.4V. I had to pulled it out and put it in to continue the charge.
Bill,
I once checked that post. I searched it roughly and did not find the testing current.
In general, the resistence is a linear one. However, the impedence of a battery might be a nonlinear one. This mean it changes with the current through it. Further, the impedence when changing might be different from the internal resistence when discharging.
Yes, some batteries, the high capacity ones, once stopped on BC-900 when voltage is about 1.4V. I had to pulled it out and put it in to continue the charge.
Bill,
I once checked that post. I searched it roughly and did not find the testing current.
wptski
Flashlight Enthusiast
tacoal:
Look at the graphs as all are marked with cell brand, capacity and 1C. A few have other notations.
Look at the graphs as all are marked with cell brand, capacity and 1C. A few have other notations.
wptski
Flashlight Enthusiast
The same 2.3Ah Duracells discharged and charged at 2A with a small fan attached to the bottom of the unit forcing air through the slots near the metal folding stand. Inputs, time, temperature, capacity with a 500ma discharge rate and capacity with a 500ma discharge rate of a 16 hr break-in.
Slot#1= 2106mAh, 71 min, 127.3F, 1969mAh, 2001mAh
Slot#2= 2050mAh, 69 min, 113.2F, 1969mAh, 2249mAh
Slot#3= 2079mAh, 70 min, 113.2F, 2013mAh, 2276mAh
Slot#4= 2050mAh, 68 min, 106.2F, 2018mAh, 2242mAh
The Slot#1 cell has a bit higher impedance, not sure if that accounts for the higher temperature.
EDIT: Added break-in capacity with a 500ma discharge rate. Slot#1 has the higher impedance reading cell.
Slot#1= 2106mAh, 71 min, 127.3F, 1969mAh, 2001mAh
Slot#2= 2050mAh, 69 min, 113.2F, 1969mAh, 2249mAh
Slot#3= 2079mAh, 70 min, 113.2F, 2013mAh, 2276mAh
Slot#4= 2050mAh, 68 min, 106.2F, 2018mAh, 2242mAh
The Slot#1 cell has a bit higher impedance, not sure if that accounts for the higher temperature.
EDIT: Added break-in capacity with a 500ma discharge rate. Slot#1 has the higher impedance reading cell.
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coppertrail
Enlightened
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- May 21, 2006
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Either my DMM is way off, or the C9000 doesn't accurately determine cell voltage.
I've been storing 4 Powerex 2500 mAh cells in the refrigerator for about 2 months. I let them get to room temp and tested them with my DMM
Voltages were as follows:
1. 1.24V
2. 1.24V
3. 1.28V
4. 1.28V
When I put them in this order in slots 1-4 on the C900 for a discharge cycle, the voltages displayed as follows:
1. 1.17V
2. 1.17V
3. 1.15V
4. 1.15V
Something seems way off here unless I'm missing something?
I've been storing 4 Powerex 2500 mAh cells in the refrigerator for about 2 months. I let them get to room temp and tested them with my DMM
Voltages were as follows:
1. 1.24V
2. 1.24V
3. 1.28V
4. 1.28V
When I put them in this order in slots 1-4 on the C900 for a discharge cycle, the voltages displayed as follows:
1. 1.17V
2. 1.17V
3. 1.15V
4. 1.15V
Something seems way off here unless I'm missing something?
wptski
Flashlight Enthusiast
Chris:
Yes, I noticed a difference too but I don't remember which way it was and it was on the original version also.
Yes, I noticed a difference too but I don't remember which way it was and it was on the original version also.
SilverFox
Flashaholic
Hello Chris,
I believe the C9000 displays the voltage under the discharge load.
Tom
I believe the C9000 displays the voltage under the discharge load.
Tom
SilverFox said:
SilverFox, how does one get to set the charging rate higher than 2000 MAH on the CHARGE mode? I intend to buy rechargeable C and D batteries.
BREAK-IN mode goes up to 20.00 Ah, but I can only set the charging rate of my MH-C9000 (0FAB02) on CHARGE mode to a max of 2000 MAH.
Should CHARGE mode of the old model (0FAB02) be able to set current from 200 MAH up to 20.00 Ah?
coppertrail
Enlightened
- Joined
- May 21, 2006
- Messages
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Tom - Thank you, I was starting to see that it's not measuring the exact voltage of the cell as it was remaining pretty steady throughout the duration of the discharge cycle.
verge said:
First on the BREAK-IN MODE you are entering the battery capacity so the charger will choose a charge rate of 0.1C and a discharge rate of 0.2C for this battery capacity.
EX: If you enter 2500 mah
It will charge at 250 mah (0.1C of 2500 mah)
And discharge at 500 mah (0.2C of 2500 mah)
The charger is only capable of charging rate between 200 to 2000 mah.
Hope this help !
SilverFox
Flashaholic
Hello Verge,
First we need to define some terminology...
mAh refers to capacity. mA refers to current.
The maximum charging rate for the C9000 is 2000 mA. This applies to all versions.
The C9000 has a timer that limits the charge. The original timer was set to terminate at 20000 mAh of charge. If you were charging at 2000 mA, the timer would shut things off at 10 hours. If you were charging at 1000 mA, the timer would shut off at 20 hours, and so on.
The improved C9000 has that timer reduced from 20000 mAh to 4000 mAh. Now, if you are charging at 2000 mA, the timer will shut things down after 2 hours.
The Break-In mode on the C9000 involves charging at 0.1C for 16 hours. Since the maximum charge rate of the C9000 is 2000 mA, the maximum battery capacity you can have and still charge at a 0.1C rate is 20000 mAh.
Tom
First we need to define some terminology...
mAh refers to capacity. mA refers to current.
The maximum charging rate for the C9000 is 2000 mA. This applies to all versions.
The C9000 has a timer that limits the charge. The original timer was set to terminate at 20000 mAh of charge. If you were charging at 2000 mA, the timer would shut things off at 10 hours. If you were charging at 1000 mA, the timer would shut off at 20 hours, and so on.
The improved C9000 has that timer reduced from 20000 mAh to 4000 mAh. Now, if you are charging at 2000 mA, the timer will shut things down after 2 hours.
The Break-In mode on the C9000 involves charging at 0.1C for 16 hours. Since the maximum charge rate of the C9000 is 2000 mA, the maximum battery capacity you can have and still charge at a 0.1C rate is 20000 mAh.
Tom
Bones
Enlightened
Greetings from another new member who is very appreciative of the tremendous amount of hard won knowledge so generously shared in this forum.
It appears evident that the C9000 benefits from forced venting, so I thought I would solicit some input on a semi-permanent modification.
There's enough room inside the charger (in the upper right corner) to mount a small fan, such as those used to vent video cards.
What I am wondering is whether the fan could be powered from the charger itself, and if so, whether it would be okay to solder the fan leads to the power points on the bottom of the circuit board under the dc in connection?
The typical specifications of the fans I have found so far are 12volt dc, .08 amps and .09 watts.
If this modification works, I will, of course, share all the details.
It appears evident that the C9000 benefits from forced venting, so I thought I would solicit some input on a semi-permanent modification.
There's enough room inside the charger (in the upper right corner) to mount a small fan, such as those used to vent video cards.
What I am wondering is whether the fan could be powered from the charger itself, and if so, whether it would be okay to solder the fan leads to the power points on the bottom of the circuit board under the dc in connection?
The typical specifications of the fans I have found so far are 12volt dc, .08 amps and .09 watts.
If this modification works, I will, of course, share all the details.
coppertrail
Enlightened
- Joined
- May 21, 2006
- Messages
- 920
Although not powered from the charger, this is what I rigged up: (Thanks dekelsey!)
SilverFox, thanks for clearing my confused mind.
Powerex 11,000 mAH D battery x 0.1C (1100 mA) = 10 hrs.
Powerex 11,000 mAH D battery x 0.2C (2200 mA) = 5 hrs.
The 4000 MAH limit is not even half of the Powerex D 11,000 mAH battery's rated capacity.
I can use only the BREAK-IN mode to charge C and D cells. I mistakenly presumed that the new C9000 model's losing the capability to charge C and D cells pertains to a MAH setting in the CHARGE mode of my charger.
Thanks again for the response.
Powerex 11,000 mAH D battery x 0.1C (1100 mA) = 10 hrs.
Powerex 11,000 mAH D battery x 0.2C (2200 mA) = 5 hrs.
The 4000 MAH limit is not even half of the Powerex D 11,000 mAH battery's rated capacity.
I can use only the BREAK-IN mode to charge C and D cells. I mistakenly presumed that the new C9000 model's losing the capability to charge C and D cells pertains to a MAH setting in the CHARGE mode of my charger.
Thanks again for the response.
dekelsey61
Newly Enlightened
This picture of the fan on top of the C9000 charger that coppertrail is showing works great!!! It pulls the hot air out of the charger that way your batteries stay really cool!! I have charged some batteries at a very high rate at at the end of the charge the batteries are barely 100F with the fan on top of the charger. NO HEAT ISSUES ANYMORE!!
Dan
Dan
coppertrail said:Although not powered from the charger, this is what I rigged up: (Thanks dekelsey!)
SilverFox
Flashaholic
Hello Verge,
You are almost correct...
You can use the 2000 mA rate to charge your 11000 mAh cells, however they will time out after 4000 mAh. When this happens you just start the charge again.
If they are completely drained, you would put them in your external cell holder and start the charge at 2000 mA. 2 hours later, you would have to restart the charge again, and 2 hours after that, you would do it one more time. Charge time would be a little over 6 hours.
If they aren't completely drained, it would go faster.
Tom
You are almost correct...
You can use the 2000 mA rate to charge your 11000 mAh cells, however they will time out after 4000 mAh. When this happens you just start the charge again.
If they are completely drained, you would put them in your external cell holder and start the charge at 2000 mA. 2 hours later, you would have to restart the charge again, and 2 hours after that, you would do it one more time. Charge time would be a little over 6 hours.
If they aren't completely drained, it would go faster.
Tom
Bones
Enlightened
Thank you for your replies coppertail and dekelsey61.
It was actually your posts confirming that the concept works great that got me thinking about an internally mounted fan.
If it turns out that that a fan can't be powered from the charger, I will certainly be following your lead with an external fan.
However, I would still like to try an internal mount first, if for no other reason than just to see if it can be done.
Hopefully, I won't end up frying the charger...
It was actually your posts confirming that the concept works great that got me thinking about an internally mounted fan.
If it turns out that that a fan can't be powered from the charger, I will certainly be following your lead with an external fan.
However, I would still like to try an internal mount first, if for no other reason than just to see if it can be done.
Hopefully, I won't end up frying the charger...
wptski
Flashlight Enthusiast
What, it doesn't decrease throughout the cycle????coppertrail said:
