Wednesday, April 30th, 2008
Go Rechargeable!
Replacing your regular “disposable” alkaline batteries with rechargeable ones can make a big differences to both the environment and your wallet. While the initial cost is considerably higher, the life time costs work out in your favor.
As a parent of two preschoolers, I am constantly replacing batteries in toys. Even though we have lots of battery free toys (my preferred type), some of my kids favorites do require batteries such as the mini-electric keyboard and various cars, trucks and flashlights. To minimize the impact of these toys, I have made a huge effort to switch to rechargeable batteries. So, how much money does it save in the long run?
To start, let’s focus on the most common battery size AA. Most of the toys my kids have use AA batteries and they are readily available and easily recharged. You can buy a pack of 4 AA 2500mAh Energizer akaline battieries with a charger for $23.49 from CVS (a 4 pack of rechargeable batteries alone is only $12.49). A pack of 4 Energizer MAX Alkaline AA batteries from CVS cost $4.79 so the difference for 4 batteries is $7.70.
Now, how much does the power to recharge them cost. I measured the kWh used recharging 4 AA 2500 mAh batteries (the Energizer priced above) after my kids had thoroughly discharged then in their truck and it took 0.03 kWh. That works out to be half a cent per charge at my electric rate of $0.175/kWh. So, it would take recharging them just 5 times to make back the difference in cost between the rechargeable with a charger and regular akaline batteries. If you already have a charger, then it only takes recharging them three times. Thankfully the rechargeable batteries are good for over 100 charge cycles leading to a cost savings over the lifetime of the 4-pack of rechargeable batteries of $455.
Assuming the energy to produce akaline batteries vs rechargeable in the factory is about the same, means you also save lots of energy that doesn’t need to go into the manufacturing of the disposable batteries, not to mention the chemicals that won’t go into into the landfill.
You probably won’t be able to get away completely from non-rechargeable batteries, as rechargeable batteries have a slightly lower voltage 1.2V instead of 1.5V so some devices do not do so well with them. I have a travel alarm clock that said not to use rechargeable batteries, but of course I had to try. When I did, I was disappointed that the warning was legit. You are still helping out even if you just replace a few of your batteries with rechargeables, so start small and go from there. And a tip for other parents, have a few spare already charged batteries on hand so that you can satisfy your kids when their favorite toy stops working and they say “daddy, please change the batteries.” A typical recharge time with the charger described above is over 5 hours and kids usually are not that patient.
