I have mostly favored disposable alkaline batteries over any brand of rechargeable batteries for all household electronics until I discovered Sanyo Eneloop rechargeables. Do they perform as good as those use-and-throw high powered alkaline batteries that we love so much? Well, in most cases they do, but there are a few differences.
Eneloop is a brand of NiMH rechargeable batteries developed by Sanyo, a Japanese Company. These batteries are known for their high build quality, low discharge rate leading to longer shelf life, high charging cycles, and high capacity.
Sanyo has been acquired by Panasonic and now Eneloop batteries are made and marketed by Panasonic.
So are they worth it? Eneloop batteries are worth every penny if you have a lot of electronic devices and gadgets at home which depend on AA-type or AAA-type batteries. Their longevity and high charging cycles make them convenient as well as cheaper than alkaline batteries in the long run.
I hated rechargeable batteries as they never held a charge as long as those non-rechargeable alkaline batteries. Just when you need them, you will find them dead. The only option is to charge them again for 4-8 hours before using them. On top of that, if you recharge them too many times, their capacity to hold a charge decreases. And yes, you cannot charge them completely unless they are completely discharged. So forget about topping-up a half discharged battery. With all these issues, rechargeables were not worth it.
Why today’s Rechargeable Batteries are Better
The pathetic situation of rechargeable batteries has changed drastically with the introduction of NiMH rechargeables. These rechargeables can hold a charge for long, and their capacities are comparable or even exceed alkaline batteries. Yes, they are expensive than alkaline batteries, but if you consider their reusability and longevity, they will come out cheaper, much cheaper, in the long run.
A lot of companies are making NiMH rechargeable batteries, and Eneloop is probably the best rechargeable battery, as far as their shelf-life is concerned. Sanyo Eneloop has been a well-known brand even before Panasonic acquired Sanyo. I have some of the original Sanyo Eneloop batteries even today, as well as the newer Panasonic ones.
As you can see, they look almost identical except for the branding. My Sanyo Eneloops are very old, as I have been regularly using them for more than eight years now. However, they perform as good as ever.
This is what Eneloop batteries are known for, and what makes them comparable to alkaline batteries. To be honest, at the time of buying these batteries for the first time, I was not aware of this. Or rather, I did not believe it completely.
However, one day while shaving, my battery-powered electric shaver ran out of juice. As I could not find any spare alkaline batteries at home, I popped in two Eneloop batteries inside it and continued shaving. Incidentally, these Eneloops were sitting idle in my drawer for nearly 6 months.
However, the shaver was working fine, almost as if new batteries have been used. I was a bit surprised, as per my experience, rechargeable batteries almost die down, or lose most of their power when kept idle for this long.
There is something called ’slow discharge’ which every rechargeable battery suffers from. Panasonic claims Eneloop batteries have very low self-discharge, so low that if kept idle for 10 years, capacity remains up to 70%. That is just awesome, isn’t it?
This is why Eneloop batteries are pre-charged, and hence you can just take them out of the package and start using them, just like alkaline batteries.
I read somewhere that shelf life of disposable alkaline batteries is 5 to 10 years. So far as charge retention is concerned, Eneloops seem as good as alkalines. Of course, I have no proof of that, I am not going to wait 10 years and then decide on whether they are good or not. I will be happy if they can last six months to a year without losing a significant charge. That will take care of most household needs. Who keeps even alkaline batteries for more than a year?
This one is even more awesome. As per Panasonic, you can recharge Eneloop batteries 2100 times! That is, the battery will perform to its full potential for 2100 recharges till it starts showing performance degradation like not able to retain a charge, or not being able to be charged to its full capacity.
How often will you recharge? Because if you recharge your battery every alternate day, then also it will last more than 10 years! Just imagine, you will avoid buying 2100 alkaline batteries over the course of 10 years. I think it will be a good deal if these batteries are even half as good as Panasonic claims.
Maximum Capacity of Eneloop Batteries
The fourth-generation AA-sized Eneloop batteries are rated at 2000 mAh (Milli Ampere-hour). This is the maximum capacity that Eneloop can deliver now. When I first bought Eneloop batteries, they were developed by Sanyo and the max capacity was 1900 mAh.
Considering that alkaline battery capacity can go over 2500 mAh, Eneloops may seem a bit underpowered when compared to disposable alkaline batteries.
The AAA-sized Eneloop batteries are rated at 800 mAh.
Need More Capacity?
Well, some people really need that extra capacity that alkalines provide, and if you are one of them, NiMH rechargeables will not disappoint you. Even Panasonic has a higher capacity Eneloop variety that has a maximum capacity of 2550 mAh. Sanyo used to call them Eneloop XX, but Panasonic rebranded them as Eneloop Pro.
And yes, in case you are looking for the smaller variety, there are AAA-sized Eneloop Pro too. Those are rated at 930 mAh.
These types of high capacity of NiMH batteries are suitable for very high drain devices, like camera flash, electronic toys, etc.
So what is the catch? Why not just forget Eneloop and go for Eneloop Pro? Well, for all NiMH batteries, as the capacity increases, the charge retention capacity as well as the number of charging cycles decreases. Panasonic claims the Eneloop Pro holds up to 85% charge after one year, whereas the regular Eneloop can hold 70% even after 10 years. The Pro most probably will completely discharge if kept that long. It can also be recharged only 500 times, as compared to regular Eneloop’s 2100 times.
So if you charge Eneloop Pro twice per week, it should last at least 5 years. Considering their higher capacity compared to regular Eneloop, they will probably need fewer recharges. If your requirement is such that you will never need to store batteries for years without using them, then Eneloop Pro will be a better choice. However, keeping some regular Eneloop batteries in the mix may come handy on that special occasion when you accidentally run out of battery power.
I usually keep a mix of Eneloop and Eneloop Pro batteries and use them as per the need of the device.
The way you charge your rechargeable batteries ultimately defines how long it will take to charge them completely, and more importantly, the longevity of your batteries. Are you concerned whether your Eneloop batteries can really be charged 2100 times? Well, they probably can be, if you don’t damage your batteries by using those dumb battery chargers.
These dumb chargers are timer-based and they will charge your batteries for a fixed duration of time, irrespective of whether your battery is at zero, or at 50% or even 100%. They don’t know the battery’s condition and they don’t care. If you use these chargers, they will damage your batteries in the long run.
You should look for those type of chargers which can detect the condition of the battery and then stop charging automatically when the battery is fully charged. These are known smart chargers, they are pricier than those dumb ones. If you are planning to have a long relationship with your Eneloop or any rechargeable battery, these are the chargers that you should go for.
You can charge any rechargeable NiMH with any charger that supports them. Panasonic itself sells a lot of chargers for their batteries. However, most of the better ones are hard to find in the market.
The one I use is the Panasonic BQ-CC17 Advanced charger. It can charge four regular AA-type Eneloop batteries in 7 hours, and AA-type Eneloop Pro in 9 hours approximately. For AAA-types, it takes about an hour or two less to charge completely.
You can charge the batteries in any combination – one, two, three, or four at a time, both AA-type and AAA-type together, as per your need.
Of course, the charging time will vary depending on how much charge the battery already has, and how many batteries are being charged together.
But since this is a smart charger, I am not worried about damaging my batteries.
I just put them in the charger at night, and take them out, fully charged, in the morning.
I have been using this charger for the last five years without any issues.
Panasonic also sells a popular quick charger, the Panasonic BQ-CC55 which can drastically reduce the charging time. I usually do not like quick chargers that much, but since it is sold by Panasonic, it should probably be ok for Eneloop batteries.
However, if you want to be a battery doctor, use not only Eneloop but also other rechargeables from other brands, and want to get the maximum performance out of any rechargeable battery, then you should really go for one of these advanced chargers.
- PowerEx MH-C9000
- Maha PowerEx MH-C808M
- La Crosse Technology BC700-CBP Alpha Power Battery Charger
These are expensive chargers and do a lot of other things than just charging your batteries. I have not used them, but I have heard they can even bring completely dead batteries to life. Do your research if you are going for any of these.
Want Something cheaper than Eneloop?
Eneloop batteries are probably the best rechargeable batteries out there. They are pricier than other brands, but you should think of them as a long term investment. However, if you really want something similar at a much cheaper price, then have a look at Ikea LADDA batteries. I have not used them personally but heard a lot of good things about them.
Rechargeable batteries are not for everyone and for every need. Analyze your requirements first before investing in rechargeables. If you just need to power low drain devices like TV remote or clock, then it is better to go with single-use alkaline batteries. As these devices will last a long time until a battery replacement is needed, you won’t be frequently recharging even if you use rechargeables. Hence, you won’t be saving much money.
On the other hand, if you have a lot of high-drain devices, like digital cameras, flashlights, high-performance toys, cordless landline phones, or any other device that use a lot of battery power, then rechargeable batteries can save a lot of money for you in the long run.
Before you pick up another pack of disposable alkaline batteries, think whether rechargeable NiMH will better suit your requirements. I got my first pair of Eneloops about eight years back, and they are still going strong. With normal usage, low discharge NiMH batteries like Eneloop (or Eneloop Pro) will probably last a decade before they show any performance degradation. By then, they would have paid for themselves multiple times.