eebowler
Flashlight Enthusiast
I bought this charger for $34.50 along with 12 of amondotech high discharge AA cells for my ROP. (Discovered later that the same charger can be bought from batteryspace.com for $25.95)
This is my first single channel charger and I chose it above the other two similarly shaped amondotech chargers simply because of the charging current.. The other two are overnight chargers and I really didn't want to take the chance that some time during that 10+ hr period, current would go and I'd be left with partially charged cells. I preferred that cells be charged mostly within a few hrs and left in the charger for however long after for the trickle charge to top them off. The 8800 charger according to the too short description, has a max charging current of 2000mA and in my opinion, that's too much for AA cells. (A big regret now btw.)
ACCORDING TO THE PACKAGING:
FEATURES:
· Recharges 1 piece to 8 pieces high capacity of AA or AAA Ni-MH batters at a time.
· Powered by the supplied Switching Mode Adaptor when using at home/Office or by the supplied DC Car Adaptor when using in a vehicle.
· Microprocessor Controlled- Batteries life well protected by negative delta V cut-off function
· Temperature sensor to avoid the battery from being damaged by over-heating
· 8 independent channels with individual LED display for rapid charge/trickle charge/bad cell detection & discharge function.
Red LED- Rapid charge; Green LED- Trickle charge: Flashing Red LED; Cells are not suitable for charging; Flashing Green LED – Cells are under discharging.
SAFETY FEATURES:
· Negative delta V cut-off function
· Safety timer to prevent over charge
· Thermal cut off
· Reverse-polarity protection
· Bad cell Detection
WARNING:
· Batteries are not charged as shipped. Must be charged prior to first use.
· Charge only Ni-MH type batteries on this charger.
· Batteries may leak or explode causing personal injury if inserted improperly, disposed of in fire, mixed with other battery types, or short circuited.
·
CHARGING TIME:
Ni-MH Charging time
1300mAh 120 minutes
1600 mAh 140 minutes
1800 mAh 160 minutes
2000 mAh 180 minutes
2100 mAh 190 minutes
2300 mAh 200 minutes
2500 mAh 210 minutes
650 mAh 60 minutes
700 mAh 65 minutes
800 mAh 75 minutes
900 mAh 85 minutes
SPECIFICATIONS:
Charge rate:………....AA/AAA size- 700mA
Trickle charge rate: AA/AAA size- 50mA
Discharge rate:…...…AA/AAA size- 300mA
CHARGING DIRECTIONS:
I'll condense it to save space.
To charge, stick 1-8 cells in the charger, plug adapter into charger then into wall.
To discharge, stick the cells in the charger, plug adapter into charger, plug adapter into wall and press the blue discharge button. After all the cells have been discharged, the RED LED will automatically light up to indicate the battery charging process start.
"NOTE: The discharge process will not function when you press the blue discharge button more than 1 min after the charging process starts."
BAD CELL DETECTION:
When charging process is started, the charger detects the condition of each of the cells in the battery compartment. If any battery is unsuitable for charging, i.e. short circuit or reversed polarity, the RED LED will flash. The damaged cell(s) should be properly disposed of.
WHAT I'VE LEARNT:
DISCHARGING:
During the discharge process, the charger will only begin recharging after all cells in the charger have been discharged. In other words, if you stick one fresh cell in the charger along with 7 dead cells to discharge, after the 7 dead cells have been discharged, they'll just sit there waiting on the fresh cell to completely discharge before all 8 cells begin to recharge at the same time. This is NOT indicated at any of the sellers' websites in their description of the charger.
That 'one minute' thing mentioned in the discharging directions is sadly true. If you have for eg, four cells discharging and you decide to discharge a fifth some time (more than a min) later, if you insert it into the charger, nothing happens. If you press the discharge button to begin discharging, nothing happens. You'll have to unplug and plug back in the charger and press the discharge button again to start discharging all five cells.
If you have four cells charging and need to discharge for eg two different cells, when you insert them into the charger, they begin recharging (along with the first four). Pressing the discharge button does nothing. You CANNOT discharge and recharge cells at the same time in this charger.
During the discharge process, with an ambient temperature of 30 deg C, cells reach a temp ranging from 44-46 deg C at the +ve nipple. (I've determined that the +ve nipple is the hottest part of the cell during charge/discharge.)
RECHARGING:
The first set of cells I recharged were AAA cells. They were a mix of Titanium and Energizer 850mAh cells. I put them to discharge and left. Some time later when I returned, I noticed the cells VERY hot. In fact, I could smell the heated plastic from the charger which itself was making a quiet but noticeable, inconsistent ticking noise. I measured the temperatures of the cells and they ranged from 54-60 degC! Within ½ hr, the cells were charged.
Along with the charger, I bought twelve 1800mAh, high discharge cells. Using this charger and my old Maha 204F charger, I began cycling them.
Here are temperature measurements for the fifth cycle.
T=140 mins: 44, 47, 45, 41, 40, 43, 45, 46.
T= 160 mins: 52, 52, 51, 45, 45, 48, 52, 50.
T= 167mins: 55, 58, 55, 51, 51, 51, 55, 55.
T= 172 mins: 59, 60, 58, 52, 54, 55, 55, 58.
While taking measurements at 172 mins, the lights in the charger started turning green indicating charge completion.
As with the AAA cells, the smell of heated plastic and that ticking noise was detected. The results above are typical of every charging process but may vary slightly as I have measured temperatures of 61degC already.
Hot off the charger, cells have an open circuit voltage of 1.39-1.40V. After hours of trickle charging, they range from 1.40-1.41V.
The charger's instructions and every advertisement for this charger mentions that it's ONLY for NiMH type cells. Of course, I had to test weather they will charge NiCd cells or not. First, a pair of AAA cells were inserted and they charged. Then I inserted the rest of the AAA cells and they also charged. So did the AA cells. The only difference I've noticed (and this is from charging once, ) is that the open circuit voltage of the NiCd cells coming off the charger were lower than the NiMH cells. Also, after sitting for a day, the NiCd cells will be closer to 1.30V while the NiMH cells will be closer to 1.35V. I'll have to run the test again and check if this happens consistently.
RATING:
I'll only give this charger 3.5 out of 5 stars because I think it's a bit dumb for a smart charger. I regret buying this charger because 1) I paid $8.50 too much, 2) it cannot charge and discharge at the same time and 3) the discharge process isn't completely independent ie, it must discharge all cells first before any cell can start charging. One result of this is 8 cells charging at the same time and if they are of the same brand/capacity, they all reach peak temperatures at the same time creating one hot combination. Oh, and if you go according to the instructions and warnings, 4) it does not charge NiCd cells. I'm a bit concerned about the heat, maybe someone can help out here.
The discharging downfall above I must admit, isn't a hugh problem since NiMH cells do not need to be deep discharged very often. It became a pain for me since I was cycling 12 new cells. Also, I'm aware that my cost, has nothing to do with the charger's performance.
Tell me about your opinions and experience with this charger. If there are any questions, ask away. I'll try my best to answer.
eebowler
EDIT 16/3/07: WRT the NiCd cells, they come off the charger at the same open circuit voltage as NiMH cells however, after sitting for a day, their open circuit voltage drops to 1.30-1.31V.
This is my first single channel charger and I chose it above the other two similarly shaped amondotech chargers simply because of the charging current.. The other two are overnight chargers and I really didn't want to take the chance that some time during that 10+ hr period, current would go and I'd be left with partially charged cells. I preferred that cells be charged mostly within a few hrs and left in the charger for however long after for the trickle charge to top them off. The 8800 charger according to the too short description, has a max charging current of 2000mA and in my opinion, that's too much for AA cells. (A big regret now btw.)
ACCORDING TO THE PACKAGING:
FEATURES:
· Recharges 1 piece to 8 pieces high capacity of AA or AAA Ni-MH batters at a time.
· Powered by the supplied Switching Mode Adaptor when using at home/Office or by the supplied DC Car Adaptor when using in a vehicle.
· Microprocessor Controlled- Batteries life well protected by negative delta V cut-off function
· Temperature sensor to avoid the battery from being damaged by over-heating
· 8 independent channels with individual LED display for rapid charge/trickle charge/bad cell detection & discharge function.
Red LED- Rapid charge; Green LED- Trickle charge: Flashing Red LED; Cells are not suitable for charging; Flashing Green LED – Cells are under discharging.
SAFETY FEATURES:
· Negative delta V cut-off function
· Safety timer to prevent over charge
· Thermal cut off
· Reverse-polarity protection
· Bad cell Detection
WARNING:
· Batteries are not charged as shipped. Must be charged prior to first use.
· Charge only Ni-MH type batteries on this charger.
· Batteries may leak or explode causing personal injury if inserted improperly, disposed of in fire, mixed with other battery types, or short circuited.
·
CHARGING TIME:
Ni-MH Charging time
1300mAh 120 minutes
1600 mAh 140 minutes
1800 mAh 160 minutes
2000 mAh 180 minutes
2100 mAh 190 minutes
2300 mAh 200 minutes
2500 mAh 210 minutes
650 mAh 60 minutes
700 mAh 65 minutes
800 mAh 75 minutes
900 mAh 85 minutes
SPECIFICATIONS:
Charge rate:………....AA/AAA size- 700mA
Trickle charge rate: AA/AAA size- 50mA
Discharge rate:…...…AA/AAA size- 300mA
CHARGING DIRECTIONS:
I'll condense it to save space.
To charge, stick 1-8 cells in the charger, plug adapter into charger then into wall.
To discharge, stick the cells in the charger, plug adapter into charger, plug adapter into wall and press the blue discharge button. After all the cells have been discharged, the RED LED will automatically light up to indicate the battery charging process start.
"NOTE: The discharge process will not function when you press the blue discharge button more than 1 min after the charging process starts."
BAD CELL DETECTION:
When charging process is started, the charger detects the condition of each of the cells in the battery compartment. If any battery is unsuitable for charging, i.e. short circuit or reversed polarity, the RED LED will flash. The damaged cell(s) should be properly disposed of.
WHAT I'VE LEARNT:
DISCHARGING:
During the discharge process, the charger will only begin recharging after all cells in the charger have been discharged. In other words, if you stick one fresh cell in the charger along with 7 dead cells to discharge, after the 7 dead cells have been discharged, they'll just sit there waiting on the fresh cell to completely discharge before all 8 cells begin to recharge at the same time. This is NOT indicated at any of the sellers' websites in their description of the charger.
That 'one minute' thing mentioned in the discharging directions is sadly true. If you have for eg, four cells discharging and you decide to discharge a fifth some time (more than a min) later, if you insert it into the charger, nothing happens. If you press the discharge button to begin discharging, nothing happens. You'll have to unplug and plug back in the charger and press the discharge button again to start discharging all five cells.
If you have four cells charging and need to discharge for eg two different cells, when you insert them into the charger, they begin recharging (along with the first four). Pressing the discharge button does nothing. You CANNOT discharge and recharge cells at the same time in this charger.
During the discharge process, with an ambient temperature of 30 deg C, cells reach a temp ranging from 44-46 deg C at the +ve nipple. (I've determined that the +ve nipple is the hottest part of the cell during charge/discharge.)
RECHARGING:
The first set of cells I recharged were AAA cells. They were a mix of Titanium and Energizer 850mAh cells. I put them to discharge and left. Some time later when I returned, I noticed the cells VERY hot. In fact, I could smell the heated plastic from the charger which itself was making a quiet but noticeable, inconsistent ticking noise. I measured the temperatures of the cells and they ranged from 54-60 degC! Within ½ hr, the cells were charged.
Along with the charger, I bought twelve 1800mAh, high discharge cells. Using this charger and my old Maha 204F charger, I began cycling them.
Here are temperature measurements for the fifth cycle.
T=140 mins: 44, 47, 45, 41, 40, 43, 45, 46.
T= 160 mins: 52, 52, 51, 45, 45, 48, 52, 50.
T= 167mins: 55, 58, 55, 51, 51, 51, 55, 55.
T= 172 mins: 59, 60, 58, 52, 54, 55, 55, 58.
While taking measurements at 172 mins, the lights in the charger started turning green indicating charge completion.
As with the AAA cells, the smell of heated plastic and that ticking noise was detected. The results above are typical of every charging process but may vary slightly as I have measured temperatures of 61degC already.
Hot off the charger, cells have an open circuit voltage of 1.39-1.40V. After hours of trickle charging, they range from 1.40-1.41V.
The charger's instructions and every advertisement for this charger mentions that it's ONLY for NiMH type cells. Of course, I had to test weather they will charge NiCd cells or not. First, a pair of AAA cells were inserted and they charged. Then I inserted the rest of the AAA cells and they also charged. So did the AA cells. The only difference I've noticed (and this is from charging once, ) is that the open circuit voltage of the NiCd cells coming off the charger were lower than the NiMH cells. Also, after sitting for a day, the NiCd cells will be closer to 1.30V while the NiMH cells will be closer to 1.35V. I'll have to run the test again and check if this happens consistently.
RATING:
I'll only give this charger 3.5 out of 5 stars because I think it's a bit dumb for a smart charger. I regret buying this charger because 1) I paid $8.50 too much, 2) it cannot charge and discharge at the same time and 3) the discharge process isn't completely independent ie, it must discharge all cells first before any cell can start charging. One result of this is 8 cells charging at the same time and if they are of the same brand/capacity, they all reach peak temperatures at the same time creating one hot combination. Oh, and if you go according to the instructions and warnings, 4) it does not charge NiCd cells. I'm a bit concerned about the heat, maybe someone can help out here.
The discharging downfall above I must admit, isn't a hugh problem since NiMH cells do not need to be deep discharged very often. It became a pain for me since I was cycling 12 new cells. Also, I'm aware that my cost, has nothing to do with the charger's performance.
Tell me about your opinions and experience with this charger. If there are any questions, ask away. I'll try my best to answer.
eebowler
EDIT 16/3/07: WRT the NiCd cells, they come off the charger at the same open circuit voltage as NiMH cells however, after sitting for a day, their open circuit voltage drops to 1.30-1.31V.
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