Eneloop Pro AAA

I use AAA lights pretty infrequently, but I figured it wouldn't hurt to have some Eneloop Pros on hand. However, I understand the trade off with a shorter life span with the increased capacity...but exactly how much added run time should I expect with these on, say a single AAA light versus a regular Eneloop?

Just estimating here but let's say an AAA light runs for 60 minutes on a white 750 mAh Eneloop, with a Pro estimated at 900 mAh that light should run for about 72 minutes...sound about right?

Depends on the drive current (among other factors) ....

You can do rough calculations based on capacity differences (typical 800mAh for eneloop AAA, vs typical 950mAh for eneloop AAA Pro)

PartyPete said:

Just estimating here but let's say an AAA light runs for 60 minutes on a white 750 mAh Eneloop, with a Pro estimated at 900 mAh that light should run for about 72 minutes...sound about right?

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Yes, that should be basically correct.

Also, Panasonic claims different self discharge rates - about 5% per year for the regular Eneloop, and 15% per year for the Pro.

PartyPete said:

...I understand the trade off with a shorter life span with the increased capacity...

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That isn't all there is to it, unfortunately. Eneloop Pros are significantly more expensive than standard Eneloops. But more importantly and often ignored until it is too late, Eneloop Pros are far more fragile, less resillient to physical abuse (dropping and knocking), practical abuse (over-discharging), and charger abuse (overcharging), usually due to the charge voltage being too low, the charger missing the dv/dt charge termination, the charger hammering the cells for far too long with that lower voltage, the cells heating up and the heat increasing the cells' resistances. Once the resistance increases in the cells enough, they become effectively useless due to voltage sag under load, and only suitable, if at all, for extremely dim super-low amp lights. The Pro's inherent fragility serves to reduce that 500 recharges life time to a fraction of that.

That being said, if you need that extra 12 minutes or so of runtime, there is no other way to get it... you pay more for it, and really a lot more.

Consider that as the cost in dollars goes up, at first the value difference per more dollar paid is high (the slope is steep). But at a certain point, the slope starts to level out. In other words, you have to pay a lot more money to get a marginal rise in "value." That extra 12 minutes of runtime will cost you more by itself than the entire capacity of a standard Eneloop. In AA format, this effect is not as bad, because you'll get a lot more capacity in AA format with Pros, about an extra 500mAh compared to the AAA Pro's extra 100mAh capacity.

Now consider how resillient standard Eneloops are. They take all kinds of abuse, so much, that there is never any special treatment needed. You can be rough with them, overdischarge them, overcharge them, and still see 1800-2200 recharges. And standard Eneloops are much less expensive. This is why users rave about them, beyond their ability to consistently hold their rated voltage under load. Somehow the great user reviews of standard Eneloops has transferred to Eneloop Pros without any rational cause. They are very different batteries. The smart value is in Eneloops, and only in very special and rare cases could Eneloop Pro's be a better choice (in AAA format).

I use (Fujitsu) Eneloop Pro in my AAA EDC, I only ever use around 10% of it`s capacity, so i only ever top it up every couple of weeks and try to avoid deep discharge so i do not reduce the cycle life, Though even if i discharged it fully virtually every time 200 cycles is going to last me a long time and battery are not that expensive to replace.

John.

chillinn said:

That being said, if you need that extra 12 minutes or so of runtime, there is no other way to get it... you pay more for it, and really a lot more.

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This, plus the possibility that the "12 extra minutes" may have been eaten up thru self discharge anyway makes them useless to me. I only have 4AA Pros and just don't like them.

I do think the Eneloop Pro's handle high drain devices better, even though you may only get 12 extra minutes which is what i don't really buy it for they seem to stay strong longer. I put in other AAA cells in a high drain flashlight and even though they have good capacity and low IR they still seem to be dimmer than the Eneloop Pro's. I don't have regular AAA Eneloops to really do a comparison and maybe someone needs to do a voltage/amp test to see if Eneloop Pro's handle high drain better than basic Eneloops. Either way i know the high capacity's won't last as long as regular capacity as they'll degrade quicker so if you do want to keep a stock of them, i go for the bare minimum and use them every so often to at least get usage out of them. If you do use them infrequently i'd keep the charge under 80% (about 1.26-1.29v) but then you may have to recharge them soon after using them. I bought an 8 pack a year or two ago of AAA cells for my LEDLenser T7 which i use infrequently. They are still under 40% IR and even at around 1.27v (about 65% charge) they still work wonderfully. I usually will recharge under 1.25v which is a bit under 50% but otherwise since i got 2 sets for the T7 it makes the task easier and combined, i still have 100%+ of the power of one set. (i actually got a new 4AAA light, the 410 lumen Coast HP7 so the cells are going to that light instead)

MidnightDistortions said:

I do think the Eneloop Pro's handle high drain devices better, even though you may only get 12 extra minutes which is what i don't really buy it for they seem to stay strong longer .... I don't have regular AAA Eneloops to really do a comparison and maybe someone needs to do a voltage/amp test to see if Eneloop Pro's handle high drain better than basic Eneloops....

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Yes, @HKJ has done these tests extensively ....