Blackout? A primer on rechargeable batteries

Compensation For 1.2v Of Nimh Batteries

In couple of devices that use 3 batteries 1.5V ones I install external bank of 4 1.2V NiMH batteries.
So far I did not have any problems that 4 fully charged batteries can have initially 5.4V or even slightly more instead of required 4.5V
Brand new 1.5V batteries initially have little bit more than 1.5V too.
Externally fitted batteries are bit cumbersome and look clumsy, but on a plus side save against internal leakage.
Also if external power bank has ON/OFF switch it is so easy to turn it to off position every time when device not used.
So far I did not use 3 batteries 1.2V instead of 2 batteries 1.5 volts.
Did anybody experiment with this configuration?

I know of a case in which an approximately 1 MWhr lead acid energy storage facility at a wind farm caught fire and burned up more or less entirely. You can only imagine the toxic contamination problem from that!

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Don’t Forget Faraday Storage

I store my electronics in a converted steel trash can to shield my electronics from a EMP or CME.

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Dan, is there any possible way you can be a positive commenter on posts without being a critic? You fail to notice how disrespectful they are to the community. Keep in mind that the articles here are not encyclopedic textbooks but excellent starting points to encourage, inspire and help members build personal resilience. We are all in this together so let’s keep building each other up.


Having lost a good multimeter to the Curse of the Duracell last year, I’m with you on this, Thachmo. On the positive side, I’ve had very good luck with Eneloop rechargeable AA & AAA batteries for a decade now. Occasionally one will go dead, at least according to the smart recharger, but I’ve never had one leak. Last winter I did a search-and-replace on everything in the house that uses AA or AAA.
On a related note, here’s a recent blog post from a retired electrical engineer on the subject of leaking Duracells: It seems to be a common complaint.
I’m starting to edge into 18650s now though. A few recent purchases use them, and it’s getting to the point where I need to get a charger and some spare batteries. Does anyone have a recommendation on these?

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Yep, these adapters are good things to have. I use them in some LED camping lanterns that are sized for D cells, and they’ll run for days on rechargeable AAs. Also, have you tried to find a C cell lately? They’re an increasingly unusual size. Being able to substitute in a common AA is handy.

Don’t Forget About Renogy Too

A very helpful article. I would just like to add that Renogy, a Canadian-based company sells some very high quality/performance products. They’re also known for having a very solid customer service experience.
Their 100Ah 12 Volt Smart Lithium-Iron Phosphate Battery
and other products in that line are on blowout now. The advantages to LiPO4 are enormous.
This Canadian bargain hunting site has lots of details
I have no affiliation with the company.
One other tip: Many of the large capacity makers, like Renogy, have calculators on their websites. These help you to figure out how much battery capacity you’ll need to run your particular set of devices.
Best wishes.

Yes, I was wondering why no one had mentioned Eneloop yet. It was suggested to me that I give them a try, so think I will!

Any recommendations on brands and chargers? Honestly, a lot of 18650-related stuff looks kind of generic and junky, but it may be just a lack of slick consumer packaging. Hard to tell. Any recommended brands? Anything to steer clear of?
It really looks like this is the new up-and-coming battery standard, and it might even replace AA & AAA over time.

I have gone to the 18650 platform for pretty much all my flashlights. May have one or two AA lights I keep around. I’ve had very good success with the KeepPower brand. The high mAh will hold a charge longer and fewer recharges. These and many other brands/sizes/types/chargers are available here: - Flashlights, Batteries, Carry Gear, Intelligent LED Lighting, and More!
I’ve also had good success with items from the Nitecore Store. Nitecore Store - Flashlights, Headlamps, Batteries and Accessories


We are all in this together so let’s keep building each other up.
Hmm. Interesting request Christopher, having just ripped poor Dan a new one…Aloha, Steve

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Where Is Eneloop?

One can’t talk about AA rechargeables without mentioning Eneloop, they are the de facto standard of hich all NiMH rechargeables are measured against. There are a lot of forum threads doing the technical analysis of all the batteries, but for the more easily consumable version, I point you to:
It’s worth mention that not all devices likes rechargeables. For example - if you have night vision devices like PVS-14, I’d also stock up Energizer L91 lithium batteries.

It’s worth mention that not all devices likes rechargeables. For example – if you have night vision devices like PVS-14, I’d also stock up Energizer L91 lithium batteries.
They will work on Eneloops too. Or for that matter, any AA; just be sure to remove a Duracell between uses, you really don't want to gunk up that gear.

Alkaline are fine but like you said, make sure to remove due to risk of leaking. Rechargeable are generally frown upon, especially since I^2 technologies are so energy efficient it’s easy to just stock up some L91s, but I suppose if it comes to that, using Eneloops are better than not being able to. :slight_smile:

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Don’t Use Duracell

We use to use Duracell exclusively. When we used 800,000 in one year
Duracell came to find out why and made this commercial around 2005:
That device is running my firmware.
Now we regret endorsing Duracell.
In 2012 they changed their design and moved manufacturing from the US
to Tunisian.
All of the batteries out of that plant WILL LEAK. Duracell does not
care, we asked them. They are riding on their past reputation.
The good design had the outside of the cylinder as Negative. The bad
design has the cylinder was Positive. To tell look at the bottom of
the battery. If you see a very small O-Ring it is the bad ones. That
O-Ring is easy to nick when inserting batteries. When that happens
the batter gets HOT. 165’F has been measured.
We’ve evaluated lots of batteries since 2012 and the Ray-O-Vacs work
better than the new Duracells by a significant margin. They work
about the same as Enegizers yet are significantly cheaper that either.
They are also still made in the USA which is important to some
military contracts we do.
Then Energizer bought Ray-O-Vac. If you look at today’s package
Ray-O-Vac’s say “Made by Energizer”.
I have a package of unused Ray-O-Vacs in my kitchen that are already
leaking, less than two years old.
I suspect they are made in the same plant in Tunisian.

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In 2012 they changed their design and moved manufacturing from the US
to Tunisian. See the details in my post above yours that I just posted.

Be very careful with anything containing Beryllium. A certain portion of the population is very allergic to it.

Rechargeables (os all types) have much lower internal resistance than non-rechargeable cells and a circuit designed for alkalines will likely over-current with rechargeables, which may overheat some things and even weld contact together.
Unfortunately some equipment is designed around non-rechargeable cells and cannot be used with rechargeable cells either because of lower voltage or lower internal resistance.

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Those are fine, but when using those, it’s important to remember the smaller cells will have much less current capacity than the larger ones. Only the voltage is the same.

Great Information

Thanks for the info. You’ve given me some other ideas to think about.
I started switching over to rechargeables a couple of years ago, thinking that eventual scarcity would make them worth the effort. I’ve been using Eneloop with pretty good results. I’ve also mixed in a few lithium rechargeable AAs and AAAs as I understand they provide constant voltage until battery capacity is zero and are better in some applications such as trail cams.
I basically cycle through my supply, rotating them like I would my pantry to ensure everything is being used equally. This allows me to have a better good idea of battery status.
Overall I’ve been pretty happy with the switch. I still keep a supply of conventional batteries on hand for emergencies, but I think our rechargeable batteries are here to stay.