OK, some points here...
First, as for the comparison to Eneloops, you might as well compare the alkalines to rechargeable AmazonBasics (white) made in Japan. From what I've heard I'm pretty sure they come from the same factory as Japanese Eneloops, though they might have been manufatured to a bit different specs (rated at fewer recharge cycles and, according to the reviews on Amazon, maybe having a bit less capacity than genuine Japanese Eneloops). Those are priced at least $2.25 per cell, while the alkalines are at least $0.28 per cell. So for the price of one Amaloop, you get 8 alkalines. This means that one rechargeable cell would have to last at least 8 times as long as an alkaline in order to be worth the price. In the case where an alkaline lasts 2 years or more, this would be 16 years for the rechargeable cell, and I'd at least doubt if this is possible because of the degradation of the chemicals.
I've read the reviews for those AmazonBasics alkalines, and it often gets mentioned that they'd have less capacity and especially higher internal resistance than other alkaline cells, so this might be one thing to consider. However, another thing I've read is that they're not as likely to leak as other brands. AmazonBasics alkalines, at least those shipped from Germany, are manufatured in China.
I only have few alkaline cells as well, but I sometimes get new ones packaged with devices I buy, and I do try to use those. Sometimes I'll use them in the device they came with (when I'm not sure how long they'd actually last in that device), sometimes not (if I've got enough rechargeables around and the device seems to be rather high-drain). The last ones I got were three AA cells in a soap dispenser (which got used up in it, but still will be handed down to lower-power devices), 4 AAA's and 1 9V in an RC forklift (which were promptly put aside and rechargeables used instead) and 2 AAA's in a digital multimeter (which it is still powered with). There are only rare instances where I will buy primaries, but they do occur. The last ones I remember were the following:
- In 1998 I bought 10 C cells for use in my multitrack cassette recorder. I used those for recordings for Orange 94.0, the radio station I was doing broadcasts on back then, and they were used for four reports in total, using up maybe 20-30% of their capacity, from 1998 to 2002, then they mostly died from old age... the last one was just recycles a few days ago after giving up the ghost in a wall clock.
- In 2000, I bought 6 D Duracell Ultras for use in my keyboard... I had a gig and forgot the power supply of the keyboard at home, and it would have taken too long to drive home again to fetch it, so I bought those batteries at the next convenience store I could find in order to make it to the gig in time. Those were then handed down to and used up in my boombox before I bought the next set of rechargeables for it in 2010 (and by that time, they were already leaking).
- In 2011 I bought an 8-pack of alkaline AA's from the discount store for the transmitter of my RC car. In the transmitter, the batteries are rather difficult to exchange, and I don't have 8 equal rechargeables. At the rate I'm using the RC car, I figured the alkalines would last for roughly 8 years anyway. I do use rechargeables for the car itself which is more power-hungry than its transmitter. Actually, that 8-pack was originally bought for the old digital kitchen scale because I thought that the batteries were the reason for it not working, but it turned out the scale itself was broken.
- In 2012 I bought some lithium CR2032 cells for the new digital kitchen scale after the one it came with only lasted for a year, but it turned out that the replacement lasts longer because it hasn't died yet.
And somehow I got an 8-pack of Duracell AA's which must have been bought in 2000 or 2001 by my parents for wall clocks and such, but I'm not sure if I should count that.
You could always take the cells out when they are finished discharging, but you'll have to monitor that.
Well, it's not that severe. I think most alkaline batteries will stand some amount of being charged and even somewhat keep the charge, though some might gas and explode when being overcharged. Or they will simply leak when recharged (especially those who are likely to leak anyway). I once tried to recharge a dead 9V battery in a dumb charger, but it only took about 57 mAh before reaching a voltage peak (which looks similar to that of NiCd or NiMh batteries, but at a higher voltage). I charged it far beyond that, and it started to gas, and then the cells first knocked off the cover and then parts of them shot out of the battery like rockets. But it might have been safe, and the battery even somewhat useable, if I had stopped the charge at the voltage peak. However, 57 mAh is much less than any rechargeable 9V would take. And this 9V was by the brand which is mentioned most often concerning leakage, and is even reported to leak often when recharged, so my mileage might have been better with another brand, and it might even be safe to recharge the AmazonBasics alkalines.
This is exactly the reason i hold onto my crap NiMH batteries. They work fine in low drain devices and you don't have to worry about alkaline leakage. I have very little use for alkalines anymore with aged/high-IR NiMH cells ready to go.
Yes, that's my plan as well. The lowest-drain devices will get the alkalines that came with devices, and the highest-drain devices will get the best rechargeables, with the worse ones being handed down to the devices in the middle where a set of batteries would last anywhere between 6 months and 2 years. However, it also depends on the peak power consumption of the device and the way the rechargeables are aging (capacity / internal resistance / self-discharge). That plan is skewed in favor of alkalines if I've still got alkalines laying around, but all rechargables are in use, and towards rechargeables if I've got spare rechargeables, but no alkalines, so it differs a bit by battery size.
They looked white online, but are in fact a shiny chrome.
