24 of 25 people found the following review helpful
AccuEvolution Ultra Low Self Discharge - Size C,
This review is from: AccuEvolution C NiMH Precharged Low Self Discharge Rechargeable Batteries - high drain, all other use (Electronics)
I heartily agree with the earlier reviews, this IS a very impressive battery, and you have to shop for good prices. I have found excellent prices on this battery here on Amazon - simply by looking around.
A bit of caution: Size C Low Self Discharge batteries are often just a AA LSD inserted into a C shell. This is NOT the case with the AccuEvolution. The AccuEvolution C is a real battery through and through - with a capacity of 4,500 mAHs (over twice as much as a 2,200 mAH re-wrap). This is why the AccuEvolution is noticeably heavy.
Real cost: I recently came across an interesting article online that compares the actual cost per amp hour of a typical alkaline battery vs this battery. A name brand size C alkaline on sale for $0.94 is shown to cost $46.81 for 100 mill amp hours, while an AccuEvolution size C priced at $9.98 costs just $0.19 (including cost of electricity and charger) per 100 milli amp hours. This is a difference of slightly over 300%.
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Initial post: Dec 14, 2011 10:46:06 PM PST
Amazon Customer says:
Not sure where these numbers came from, but here's my result: $73 per kWh for Alkaline vs. $9.80 kWh for AccuEvolution. calculation: AccuEvolution gives 4500 mAh; Non rechargeable "Bunny" batteries "C size" show 8500 mAh capacity. In common units, Power = Watts = 1000 x mA x V. Energy = kWh = 1,000,000 x mA x V. Alkalines put out about 1.5 Volts; rechargeables about 1.2 Volts. So for one discharge cycle, AccuEvolution gives about 0.0054 kWh; Bunny gives about 0.0128 kWh. But you get about 100 discharge cycles from AccuEvolution; only one discharge cycle with bunny. Price per discharge $0.94 for Bunny, $0.050 per AccuEvolution discharge. A charger probably would give you over 10,000 battery charges over its lifetime; cheapest I saw for one that does size C was $12.00; which gives $0.00120 per charge. Figure 60% coulometric charging efficiency, so it takes 0.009 kWh of power to charge the battery; at $0.20 per kWh for powerline electricity; that gives $0.0018 per charge. So AccuEvolution is $0.053 per discharge including battery, electricity, and charger cost. So cost per kWh is about $73 for Bunny and $9.80 for AccuEvolution. Did not take into account that depth of discharge typically will not go below 10 - 20% before the battery is considered flat. Also, assumed a flat discharge curve (voltage vs. amp hours), but at high power draws this is not the case, especially with Alkaline. Did not take into account the charger's internal efficiency, but it should be close to 70%. First two would be advantage AccuEvolution, last one advanatage Bunny, but this was not a close race that would be won chasing pennys in cost.
In reply to an earlier post on Aug 16, 2012 6:12:13 AM PDT
Scott in Vermont says:
Dr. Goode, or anyone: would love to see that article. Can you give us the reference? Thanks.
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