[citation][nom]Tomsguiderachel[/nom]Why/how is our test flawed? We have to test the Eneloops with its own charger.[/citation]
Of course you wouldn't know how the test is flawed, when you have no clue about the subject at hand.
And no, you don't have to use the "Sanyo" charger... even if the manufacturer mentions it'll void warranty, if another charger is used. Would you tank your car only at the manufacturer's, or "recommended" gas station chain, just because he said so? I really doubt it...
Don't think the "Sanyo electrons" are somewhat different than the other ones.
Just to point out a few blatant flaws:
- a CDP, being a complex electromechanical system, is as an inconsistent load, as you can get
- a flashlight bulb is nowhere near a constant current load, it's resistance varies extremely due to temperature, and also due to age
The fatal flaw consists mainly in the "use the provided charger" policy - see below - and the unknown state of the cells, when "freshly" bought. A new cell must be slowly charged, to full capacity - a fast charger is incapable of that - and, even better, do a few cycles, to bring it at nominal capacity - the so called "break-in".
Most cell's capacity varies a lot within the first cycles of a cell's life.
[citation][nom]bri-guy[/nom]The quick charge feature doesn't affect how long the battery will run a device for, but it can significantly cut into the battery's long term life. I've heard that it can cut its life by half to 150 to 200 recharge cycles.[/citation]
If you would have researched a bit the subject, as it would've been expected for a serious review, you would've noticed that most "fast" chargers stop the charge cycle before the cell is near full. A few do a top-off charging to get at full capacity, but most don't. About trickle charge, you can mostly forget.
Hint: look up the Telefunken U2402B(-C) datasheet, for a controller IC that is doing it, almost as it should be done. From page 4 on, you can get most of the useful data.
If the used charge algorithm is done right, a good fast charger will not affect substantially a cell's life, surely not halving it.
OTOH, the "slow" chargers have no precisely defined stop criterion - most will do just a timed cycle, to get at full capacity, independently of the charge state at the beginning, because the dip, for the largely used -dV/dt stop criterion (cost "efficiency"), is too small to be reliably detectable. This is almost surely doing some overcharging, but as the charging currents are quite low, it wouldn't affect too badly the cells.
Usage of cell packs, with slightly different capacities, or charge state, will spread the dips out, making them practically undetectable - that's one of the reasons to use chargers with individual circuits, for every cell, especially for the "fast" flavor.
[citation][nom]bri-guy[/nom]In each of the reviews, there's a note as to how many recharge cycles the manufacturer rates them for. Unfortunately, it's no substitute for actually charging, draining and charging the cells, but 1,000 charge cycles would take at least a year[/citation]
If you're doing a 1C discharge / 0.5C charge (quite light handling), you could do easily 6 cycles/day - 1000 cycles would add up to under 6 months. Way faster, if you dare to push the cell to it's limits (5Cd / 2Cc). Don't believe too much in manufacturer provided life cycle data, rarely does a cell get anyway near those ideal conditions estimations. In real life a cell is almost surely to get some abuse, which will shorten it's life...
Cycle life depends a lot on (dis)charge rate, temperature, and especially over(dis)charge - that would kill them quite fast.
Badly selected fast charge stop criteria, is a guaranteed receipt for quick death - high end temperatures are telling.