Best battery charger

Last Updated: July 11, 2019
Added the EBL size D NiMH LSD battery charger, for readers who have D rechargeables.

A quality battery charger is the most important factor in getting the maximum rated lifespan and performance from your rechargeable batteries. Cheap chargers can overcharge and thus overheat your batteries, stealing away charge/recharge cycles and shelf life that you paid a premium for and might depend on in an emergency.

Not only is a charger a critical part, it’s a relatively fragile electronic device that isn’t design for hard use in emergencies. That should cause your Spidey Sense to tingle because you don’t want to build a prepping plan around a single point of failure.

We solve that by having more than one charger across the sum of our emergency supplies and by naturally having others kinds of batteries and tools on hand — including ways to survive without any batteries at all.

Survival experts think about chargers in two categories anyway, which makes it graceful to buy one of each and have your redundancies mostly covered:

  1. High-end smart chargers that plug into a wall for daily use
  2. USB-powered smart chargers that can charge your batteries with energy from a solar panel, hand crank generator, or other renewable power source

Because experts recommend using NiMH LSD rechargeables wherever you can, and lithium-ion-based rechargeables with a built-in USB charging port in other types of gear, you can get by with a charger that has support for NiMH batteries only. Nonetheless, because there are tons of regular Li-Ion batteries (with no USB port) out there that you might come across in an emergency, we strongly preferred chargers able to handle both NiMH and Lithium-Ion chemistry types for this review.

More: Confused about the different types of battery sizes and chemistries?

The two Eneloop NiMH LCD AA/AAA starter battery packs that won the best rechargeable battery review come with an included smart charger that’s actually very good. It just doesn’t have all the features for testing, cycling, and controlling the recharge rate that a higher-end charger has. Nonetheless, the included charger is good enough as an entry into daily home use with your NiMH LSD AA and AAA batteries.

Best wall-powered chargers

Our Pick
Opus BT-C3100 Charger
Best for most people:

Opus BT-C3100 Charger

An amazing value with a sterling reputation among enthusiasts. It has many features found in more expensive chargers, and will maximize your rechargeable battery investment by prolonging each battery's lifespan.

If you didn’t get one of those included good-enough chargers, or just want a better one, the best home battery charger for preppers is the $45 Opus BT-C3100. It checks all the core boxes for a smart charger — independent charging bays and a negative delta-v charging method — plus it has overheat protection and so many other features that are normally found in more expensive competitors. With this powerful unit you can test batteries, recondition them, and manually select a charging rate. (When charging, slower is better and easier on your batteries, but sometimes you’re in a hurry and just have to get it done — so a variable charging rate is a cool feature for prepping.)

Unlike most NiMH/NiCD chargers, which can be used only with nickel-based batteries, the Opus charger will also power lithium-ion batteries. And it works with any NiMH, NiCD, or Li-Ion size you’re likely to get: AA, AAA, C, 18650, and even the more exotic and obscure sizes.

Also Great

Bonai 9V NiMH charger

One of the few chargers that works with 9V NiMH, and it's also very good. With independent charging lanes and a negative delta-V charging method, it has everythning you need.

If you went the NiMH LSD route with your 9V batteries (you should), then you’ll want to pick up the $25 Bonai 9V charger. This little unit has two independent charging bays and uses the negative delta-v method, making it perfect for keeping your 9V NiMH LSD batteries in good condition.

For those who have NiMH LSD size D cells, none of the above chargers (or the USB-powered ones, below) will physically fit a battery that large. So to charge your size Ds you’ll want the $40 EBL C, D, and 9V battery charger, which comes with a four-pack of their good-quality NiMH D cells, included.

Best USB-powered chargers

As renewal energy products (namely solar) grow in usefulness while shrinking in price, most preppers have some way to generate or capture energy without the grid. Although many solar chargers come with their own battery pack, it’s still a good idea to have a high-quality separate one.

These compact emergency and camping generators typically have USB output ports for powering phones and tablets, so to charge your batteries with them you’ll need a charger with a USB power input.

Our Pick
Great for solar:

Nitecore UMS4 USB

This is a beast of a charger from a reputable brand, and it can be powered by USB. So not only does it charge many different battery formats and chemistries, but pairs well with portable solar panels.

The best USB-powered battery charger for preppers is the $40 4-bay Nitecore UMS4, a beast of a charger so feature-rich that you could actually buy it in place of the Opus for a home charger — if you didn’t mind giving up a handful of the Opus’ niche features. The UMS4 auto-detects and properly charges as many different battery types as the Opus, from AA NiMH LSD to exotic Li-ion chemistries and sizes. And its size and micro-USB 2A power input make it compatible with popular solar chargers and cell phone chargers.

The best budget option is the $10 Liitokala LII-202 USB Rechargeable Battery Charger, essentially a compact version of the Nitecore from a more obscure maker. This well-reviewed little unit is very lightweight, meets our feature requirements for a NiMH charger, supports Li-Ion chemistry, and will charge any number of battery formats. We do have questions about its long-term durability, but we’ve tested it with solar panels and Eneloops and it does work.

Budget Picks
Liitokala LII-202 USB Battery Charger

Liitokala LII-202 USB Battery Charger

This compact 2-bay charger can handle everything from NiMH to different Li-Ion formats. Very inexpensive and capable. It's what's in some of our staff's go bags.
Bonai 8-bay NiMH Charger

Bonai 8-bay NiMH Charger

If you have the space to spare and want to charge more batteries at once, then eight independent charging bays and negative delta-v charging method make this the ultimate budget charger.

If you want to be able to charge more batteries at once and are ok with a bulkier charger, the $12 Bonai 8-Bay USB Charger is a great, larger-sized USB-powered NiMH smart charger with the core features we require for proper battery maintenance. It has eight independent lanes that can charge up to eight AA or AAA NiMH batteries at once. If it weren’t for the fact that this charger takes up much more space in your pack than the EBL Quick Smart, it would be our budget pick.

How we picked

The battery types recommend by experts — NiMH LSD chemistries in the AA size family — have special charging needs in order to perform and last as well as designed. So much so that a cheap charger can hurt the kind of NiMH batteries relevant to preppers to the point their lifespan is below that of a Li-Ion.

NiMH LSD chargers need two critical features:

  1. Independent charging bays
  2. Negative delta-V charging method

Cheap chargers power two bays at a time from the same source. As a result, if you put a full battery in one bay and a half-dead battery in the other, the base unit will either under-charge the former or over-charge the latter. Independently-charged bays are intelligent enough to switch each one on and off.

The negative delta-V charging method is what turn a dumbs charger into a “smart” one. The charging circuit measures the voltage at the beginning of a charging session, tracks it over time, and figures out when to taper off the charge. This keeps the battery from overcharging and overheating.

As good as these recommended chargers are, they aren’t made for the apocalypse, or even for camping and outdoor use. There are a handful of similar chargers marketed to campers that might look attractive for prepping — but they lack critical features, so we can’t recommend them. Until something more rugged comes along, the only thing to do is have multiple chargers you can reach for in case one gets stepped on by a leather-clad wasteland marauder.

A battery tester is optional, but nice to have

Our Pick
Amprobe BAT-200
Great backup tester:

Amprobe BAT-200

If the power goes out for long enough, you'll eventually be scrounging batteries from remote controls, toys, and smoke detectors. There's no lighter, more compact way to figure out how much juice found batteries have left than this budget tester.

Although the best smart chargers have testing features built in, you might run into a situation where you find disposable batteries and want to know how much life they have left. Smart chargers typically can’t test disposables, so some preppers add a separate tester to their home supplies. We like the $6 Amprobe BAT-200, an inexpensive and lightweight unit that can test most common types of replaceable batteries.

Why you should trust us
Jon Stokes is a co-founder of Ars Technica, founding editor of AllOutdoor, and contributing editor to The Firearm Blog. Jon's a lifelong knife collector, outdoorsman, and prepper.
Joe has degrees in Electrical Engineering and Computer Science, but has since had a diverse career. He has posted many guides and in-depth articles at on subjects where he has extensive expertise. Youth baseball is one of those subjects. AA/AA batteries and chargers is another.


    • writermak

      I’m fairly new to prepping and your website has been incredible.  Thank you!  I have a question about this article, did anybody compare/test the eneloop batteries (best rechargeable) with the Nitecore UMS4 USB (best USB charger)?  The eneloop comes with the charger but I wanted to make sure my USB option for solar would work with them as well. 

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      • Gideon ParkerStaff writermak

        I am so glad that you are enjoying our website! Thank you for checking out our different articles and for commenting here.

        The Eneloop batteries and the Nitecore charger will be an excellent choice! Even though you say you are new to prepping, it sounds like you have a great prepper mentality of thinking about your solar options and how to charge your devices. You are on the right track!

        What kind of solar were you planning on using the Nitecore with? The Nitecore is rated to work with Input: DC 5V/2A or 12V/1.5A 18W(MAX). So as long as your panel can produce this, you will be good.

        We do have another article about the best portable solar panels that would work great with the Nitecore and Eneloop. Most of the panels from this article can power up to 5V/2.4A. I personally have this panel, and know that it has more than enough power to charge batteries and another device at the same time.

        And then I just also wanted to make sure that you saw our article about the best portable power banks. A power bank can be useful to charge up with your panel and then charge the Nitecore and Eneloops, cell phone, tablet, and more when there is little sun or during the night.

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      • writermak Gideon Parker

        Thanks for replying so quickly.  Your suggestions are great!  I was looking at the portable solar panels the other day as well and was leaning toward the Cheotech 19W that is in the article.  I will have to look more closely at the Big Blue 3.  I already have a NOVOO Explorer and I love it!

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      • Gideon ParkerStaff writermak

        The Cheotech 19W panel in the article is a great choice! Guess I just wanted the larger one with more watts. But it does come at a higher price and is not as portable as the Cheotech. 

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      • writermak Gideon Parker

        Larger with more watts is not a bad thing plus it does have an extra USB port over the Cheotech 19W.  You’ve given me a little more to think about and figure out which would work better for what I may need.  Thank you!

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    • Akin

      This is one of several of your articles that has been extremely helpful to me.  Thanks!

      Question though… have you guys ever looked at the La Crosse BC1000 Alpha Power Battery Charger?  I actually have two of them and I use them all the time.  The thing I really like it it has a refresh mode as well as a test mode.  Test mode will drain batteries, then charge them fully, then tell you how much juice they’re each holding… when one of your batteries is loosing capacity, you can use the refresh mode, which drains and charges repeatedly until it judges that it’s restored as much capacity as it can.

      It only fits AA and AAA, though, so, that’s definitely a negative compared to, say, the Nitecore charger.

      Anyway… just curious, as I don’t think any of the chargers you recommend has a test and refresh mode.

      Maybe time to update the article?  😀


      (BTW I’m not affiliated with La Crosse in any way, I just like that charger of theirs!  Also that’s *not* any kind of affiliate link)

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      • Supersonic Akin

        I haven’t heard of the La Crosse Alpha Power, nice suggestion. I’m a tech nerd and love seeing new things. It does look like the superior model to the article’s next comparable model the $50 Opus BT – C3100. Do you feel like the refresh and test mode are worth an additional $40? 

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      • Akin Supersonic

        They’re a lot cheaper at Amazon.  You also get a case and eight rechargeable batteries (four each AA and AAA).  They’re nothing compared to Eneloops, but whatever.

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      • Akin Akin

        Ya know what, I just re-read the description of that BT-C3100.  Looks like it has a test mode and reconditioning as well.

        I could *swear* that when I looked into it before, it didn’t mention anything like that before.  Huh.

        Also, on Amazon, some of the reviews mention issues with the cooling fan.  I’m not even sure if my La Crosse ones have a fan…

        Given that it also will charge 18650s, I may need to re-evaluate.

        Still wouldn’t mind an update to the article for 2021…

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      • Gideon ParkerStaff Akin

        Akin – Thank you for the recommendation. We periodically go over articles and update them for the latest and greatest recommended products and this article is on our radar.

        5 |
      • Akin Gideon Parker

        If you guys ever do update this article, Nitecore has a new charger that runs off of USB-C which might  be worth looking at…

        The display appears to have a lot less information on it, but if it runs off of USB-C it should have a lot more power.  Then again, if we’re running it off of solar in the field, that might be a moot point since a lot less power will be available.  *shrug*

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    • TraceContributor

      Thanks for the information. I’m in need  of a new (better) battery charger and I came to TP to see if you had one — & here I am. Good recommendations that I will be following! (You guys have become the first place I check for gear reviews & recommendations.)

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