Turbo DV8
Flashlight Enthusiast
Huge difference between 1700 & 1800 Duracell AA's incl. w/ Power Gauge/Value chargers
So I picked up one of Duracell's Power gauge chargers ($20) to see if it would be suitable to lighten some of the more menial, strictly charging chores from my two BC-900's. It advertises four individual charge status indicators, and "safety protections & microprocessor controls." It sounded like a smart charger, so I thought why not try it. Just for fun, I also picked up a Duracell "Value Charger" for about $16. Although the Value charger package info suggests individual indicators, which might suggest individual monitoring also, upon removing the product from package and seeing behind the piece of advertising paper which blocks direct view of the front of the charger while in the package, there is in fact only one indicator, so I didn't even bother trying it out. If you like nice owner's manuals, you won't like the instructions which come with these chargers, unless you call the odd-shaped thin carboard packaging sleeve an owner's manual, because that is where the instructions reside for all posterity. I will mention briefly my initial thoughts on the Power gauge, but my main discovery was the huge difference in the quality of the cells which are included with each charger.
OK, Power Gauge ... Each bay has three red charge status LED's, and one green "charge complete" LED. The back of unit says 400 mA x 4. Back of package says "charges in 4 hours." I am thinking "not" on both counts. Even four 2000 mAh cells with a good bit of charge remaining took 6-7 hours to "top off." When inserted in the charger, only the first LED lit up for the first 2-4 hours. This happened repeatedly with other cells. It tops the cells off nicely, as determined after the fact with a capacity run on the BC-900. Can't determine the termination voltage, since there is absolutely no room to sneak a probe onto the positive charger contacts. I tried sneaking a thin strip of aluminum foil between the positive cell contact and charger contact when inserting the cell, but the charger wasn't having anything to do with that. It would not even initialize the cell, giving a flashing error reading on the LED. Same with trying to measure the current. Can't sneak an ammeter into the works without the charger noticing and crying "FOUL!" So the longer-than-advertised charge times could be either the charger holding peak voltage for a very long time, or a lower-than-advertised 400 mA rate. In either case, the bays do seem to charge, monitor and terminate independently, which is nice. The clear, smoke-colored cell cover is slotted for ventilation, and will also stay fully open, or if you like, even half-open (has a detent.)
Now for testing the included cells. "Why bother?", one might ask. Because it's fun to do on the BC-900? Get this: the Value charger comes with 1800 mAh cells. The Power Gauge comes with 1700 mAh cells that look identical except for the rating. I ran an initial test on the four 1700 cells on one BC-900, and the 1800's on the other BC-900. The 1700's blow the 1800's out of the water! On a top-off, 350 mA discharge, and 700 mA charge, the 1800's capacities were all over the board, as low as 1300 mAh and the others nowhere near rated capacity. I then put them through a refresh, and after several cycles, they struggled and managed to almost hit their rated capacity, but some still seemed weaker on the discharge under load. One might consider this all to be normal for cheap NiMH cells sitting unused in a package for who knows how long. But check out the 1700 mAh cells! Even on the initial test (top-off/discharge/charge) all four 1700 cells ran neck-to-neck, finishing at between 2200-2260 mAh! A subsequent refresh terminated after the second charge, with no increase in capacity. Not that I expected it! Hell, I'm happy enough that they are putting out 29-33% above rated capacity. It's just amazing to me that the 1700's can test together so evenly and have such abundant capacity, while supposed identical cells rated 100 mAh higher, are such dogs in every respect. The difference was so dumbfounding, I even questioned if perhaps there was a discrepancy between my two BC-900's, so I ran the test again, putting the 1700 & 1800 cells in opposite BC-900's, but the final cell results remained the same regardless of which BC-900 I used. (It is worth noting that some question if the v33 charges/reads the same level as the v32. The two BC-900's I use are composed of one v32 and one v33, so this is a testimony to how evenly the two versions charge.)
Anyway, just some fun with battery chargers.
So I picked up one of Duracell's Power gauge chargers ($20) to see if it would be suitable to lighten some of the more menial, strictly charging chores from my two BC-900's. It advertises four individual charge status indicators, and "safety protections & microprocessor controls." It sounded like a smart charger, so I thought why not try it. Just for fun, I also picked up a Duracell "Value Charger" for about $16. Although the Value charger package info suggests individual indicators, which might suggest individual monitoring also, upon removing the product from package and seeing behind the piece of advertising paper which blocks direct view of the front of the charger while in the package, there is in fact only one indicator, so I didn't even bother trying it out. If you like nice owner's manuals, you won't like the instructions which come with these chargers, unless you call the odd-shaped thin carboard packaging sleeve an owner's manual, because that is where the instructions reside for all posterity. I will mention briefly my initial thoughts on the Power gauge, but my main discovery was the huge difference in the quality of the cells which are included with each charger.
OK, Power Gauge ... Each bay has three red charge status LED's, and one green "charge complete" LED. The back of unit says 400 mA x 4. Back of package says "charges in 4 hours." I am thinking "not" on both counts. Even four 2000 mAh cells with a good bit of charge remaining took 6-7 hours to "top off." When inserted in the charger, only the first LED lit up for the first 2-4 hours. This happened repeatedly with other cells. It tops the cells off nicely, as determined after the fact with a capacity run on the BC-900. Can't determine the termination voltage, since there is absolutely no room to sneak a probe onto the positive charger contacts. I tried sneaking a thin strip of aluminum foil between the positive cell contact and charger contact when inserting the cell, but the charger wasn't having anything to do with that. It would not even initialize the cell, giving a flashing error reading on the LED. Same with trying to measure the current. Can't sneak an ammeter into the works without the charger noticing and crying "FOUL!" So the longer-than-advertised charge times could be either the charger holding peak voltage for a very long time, or a lower-than-advertised 400 mA rate. In either case, the bays do seem to charge, monitor and terminate independently, which is nice. The clear, smoke-colored cell cover is slotted for ventilation, and will also stay fully open, or if you like, even half-open (has a detent.)
Now for testing the included cells. "Why bother?", one might ask. Because it's fun to do on the BC-900? Get this: the Value charger comes with 1800 mAh cells. The Power Gauge comes with 1700 mAh cells that look identical except for the rating. I ran an initial test on the four 1700 cells on one BC-900, and the 1800's on the other BC-900. The 1700's blow the 1800's out of the water! On a top-off, 350 mA discharge, and 700 mA charge, the 1800's capacities were all over the board, as low as 1300 mAh and the others nowhere near rated capacity. I then put them through a refresh, and after several cycles, they struggled and managed to almost hit their rated capacity, but some still seemed weaker on the discharge under load. One might consider this all to be normal for cheap NiMH cells sitting unused in a package for who knows how long. But check out the 1700 mAh cells! Even on the initial test (top-off/discharge/charge) all four 1700 cells ran neck-to-neck, finishing at between 2200-2260 mAh! A subsequent refresh terminated after the second charge, with no increase in capacity. Not that I expected it! Hell, I'm happy enough that they are putting out 29-33% above rated capacity. It's just amazing to me that the 1700's can test together so evenly and have such abundant capacity, while supposed identical cells rated 100 mAh higher, are such dogs in every respect. The difference was so dumbfounding, I even questioned if perhaps there was a discrepancy between my two BC-900's, so I ran the test again, putting the 1700 & 1800 cells in opposite BC-900's, but the final cell results remained the same regardless of which BC-900 I used. (It is worth noting that some question if the v33 charges/reads the same level as the v32. The two BC-900's I use are composed of one v32 and one v33, so this is a testimony to how evenly the two versions charge.)
Anyway, just some fun with battery chargers.
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I enjoyed reading it.
