AA Wall Charger for a Thru-Hike

Dan, first of all you want to think about the batteries. Some rechargeable types can tolerate fast charging, and others can't. Some of that has to do with the specifics of the battery chemistry and how it tolerates high heat. If you take a normal-speed battery and recharge it at a fast speed, you may very well cook the battery, and its life will be drastically limited. Some chargers simply increase the voltage to the batteries. That speeds up the process, but it is not always the best technique unless the batteries are built for it.

On one thru-hike, about how often do you expect to need to recharge? Do you know that you will always find a suitable power receptacle? Do you intend to transport the charger in your pack, or by mailing it in a bounce box?

–B.G.–

I'm using Duracell Ion AA's, which are supposed to be a lot like Eneloops but a bit higher capacity (2400 mAh)
http://www.mec.ca/product/5036-680/duracell-rechargeable-ion-core-aa-batteries-4-pack/?q=duracell%2BAA

I don't need to charge them in 15 min, but I'd like to charge at 700mAh rather than 360mAh so it takes 3-4 hours instead of 8. We'll just have 4 batteries, so if we can do one 3-4 hour charge that'll be reasonable. If the charger only holds 2 batteries then I'd want it to be faster.

We intend to carry the charger, which is why I'd like to have something lighter than 1/4 lbs. We'll probably be charging every 4-7 days, so that's maybe 30-40 charges over the summer. We're both using Zebralights which take a single AA. So we're going to carry two AA's each. We don't know that we'll always find a power outlet, but we can always grab some alkaline's or just make do in the rare event we have a hard time finding a power outlet at a coffee shop or restaurant.

One to check out.

Sanyo SEC-TDR02N, 56.7g (in) (out)

Dan, you might want to go through the math and the milliampere-hours per charge. Often it is lighter to carry a few lithium primary AA batteries rather than carrying a charger plus swap spares.

–B.G.–

My stock Sanyo Eneloop Ni-MH Battery Charger is 101 g.

A Panasonic BQ-390 Quick Charger is 85 g.

I like the eneloop chargerss and batteries a LOT. Use them for double/triple a-sized batteries as well as nine volts (for musical pursuits). They are fast, not 8 hours, maybe 2-4; I really can't give you an answer but could do a times test if you need.

But … Could you just mail a battery or two with your food to re-supply points, or is this trip unsupported?

Thanks for the info. You guys rock. That 2 x AA Sanyo (SEC-TDR02N) looks like it's gotta be light. Waiting 5 hrs x 2 is a bit high, but it might be the way to go.

Paul, thanks for the info on the Panasonic BQ-390. That's definitely better than what I have now.

Brian, I'm shopping in town mostly (rather than mailing boxes) because it's less pre-trip planning.

"Often it is lighter to carry a few lithium primary …"
Yeah it would be. The batteries are quite a bit lighter (~20g vs. 30g = 10g saved x 4) and there's no charger to carry. However NiMH is way cheaper and recharging is easier on the environment, so I'm pretty set on NiMH. I'd consider rechargeable lithium (ie. 14500 cells) but that wouldn't save as much weight since I'd still need a charger and my H51 won't run 'em.

On the PCT in 2009 and AT in 2012 I carried a USB travel charger that charged 2 AA/AAA dual batteries. I could plug it into the USB/AC wall plug that I carried for my Cell phone and MP3 player. It took a several of hours to charge 2 AA's, but I had no issues with how well they charged. The extra weight of the charger was partially made up by the fact that I didn't have to carry spare batteries since I could top them off before I left town. No more guessing how much charge my regular batteries had left in them and having to carry spares just in case. It also saved money compared to constantly buying new batteries on the trail.

My current USB based charger I bought last summer weighs 1.16oz/33g by some no name company GP PowerBank. Its not as durable looking as the Energizer one I use to carry, but it was lighter and does work.

Check out some of the chargers Sanyo has on Amazon. They have a 4 battery wall charger with a retractable AC plug that looks like it would be about as light as that sort of charger would be and they have a smaller 2 battery USB travel charger like I described above.

Energizer Compact Charger CHDC8: 4.0 oz (112 grams), 4 hour charge time for batteries 2100-2500 mAh, more specs here:

http://data.energizer.com/PDFs/chdc8.pdf

However, read the instructions carefully (or test before you go), I see some hints that it might recharge only 2 batteries at a time. There are several dain-bramaged chargers on the market that hold several batteries, but charge only one or two at a time.

You might want to look at the Eneloop “XX” AA batteries, 2450 mAh capacity, but only 500 recharges.

http://www.eneloop.info/eneloop-products/eneloop-batteries/eneloop-xx.html

Available from Amazon and other sources.

— Rex

Hmm….112g for that Energizer Compact Charger. It's fast and compact but I was hoping it would be a bit lighter. Still, it's an option to consider. My ideal is 4 x AA capacity, 60-80g and 3-4 hr charge.

Sean, thanks for the info. I'll check out the USB based chargers. I may need a USB->AC plug anyways for my iPod Shuffle, so I could potentially get a double one and use that if saves weight.

Dan,
I'm kind of in the same boat as you for the PCT. I'd like to use NiMH batteries for environmental/logistical reasons, so I'll be needing to charge them occasionally.

I also need a USB charger for my phone and my wife's phone.

Maybe something like this will work?
http://www.amazon.com/EZOPower-Universal-Charger-Sgh-i777-BlackBerry/dp/B007RW36VO/

Ideally I'd like a wall charger with USB ports and two AA/AAA charger ports. Not sure if that exists though.

http://www.amazon.com/Sanyo-eneloop-Pre-Charged-Rechargeable-Batteries/dp/B004UAG776/ref=sr_1_1?s=electronics&ie=UTF8&qid=1390814917&sr=1-1&keywords=MDU01

on Sanyo site this one is less than 50g (needs to be combined with USB wall charger which suppose to have in your pack anyway for cellphone (?), so maybe a dual USB charger is a good solution. maybe something like this: http://tinyurl.com/oa9tqdt 1.4 oz)

For me, 2 x AA chargers are likely out because I can't wait 4.5 hours x 2 in a coffee shop. That little 48g Sanyo USB looks awesome, but it would be "stupid light" in my circumstance. For others with fewer AA's it would be great.

Derek, when are you starting the PCT? We're hoping to start a bit early (April 15-20 ish) and then head back to kick-off. My wife and I are also carrying an iPad mini (journalling, email) and an iPhone (music, email) which we are going to charge with a dual USB wall adapter like this:
http://istoreworld.com/ca_en/power-cube-duo

I'd really like to do all my charging from one double socket wall outlet, but our camera needs to plug in and then there's the AA charger, so it seems I need 3 sockets unless I get an AA USB charger and a 3-4 USB wall adapter like this:
http://www.isound.net/4-usb-wall-charger-pro.html

It seems like there aren't any fast 4 x AA USB chargers though.

"Ideally I'd like a wall charger with USB ports and two AA/AAA charger ports. Not sure if that exists though."
Sanyo made the KBC-E1S, which is a USB charger for two AA's (280 min) and it also has single female USB port it seems so you can charge your devices off of it.
http://lesterchan.net/blog/2009/09/21/sanyo-eneloop-mobile-booster-kbc-e1s/

For lighter weight in a 4 bay charger, look for a folding US plug.

Ultralast Smarter Charger

•Two-channel design allows for charging AA or AAA rechargeable batteries in pairs of 2, up to 4 batteries at once.
•LED indicator light on each channel illuminates—
◦RED when charging, GREEN when charging is complete.
•Charge electronic devices through side USB port.
•Folding AC plug folds into back of charger— no extra parts to keep track of!
•Compact design for easy storage and travel use.
•Charges batteries in 4 to 6 hours, depending on how many batteries are loaded and actively charging.

Watson 4-Hour Rapid Charger , 79.4 g

Not sure on charge times, but I have one of these and like it. I'm sure you can find more info.

it sounds like you've got this dialed in…
but i'll cast a vote in this direction:
do not forsake the values of reliability & long life.
imagine your camera failing cos the fully-charged Batt's somehow were not.
now youre looking at 3-4 days of photolessness till the next town stop, et cetera.

re – enviro considerations
consider the amt of energy you will burn just getting to and from the trail from your home…a few AA's is nothing compared to that.

just thinking out loud
have a GR8 hike!

Thanks for the help guys. I'm reluctantly starting to conclude that I can buy a charger than is either lighter or faster, but not both.

There are a lot of fast claims on chargers, but even a 4 hour charger isn't that fast if the quoted time is for two 700 mAh AAA's and I need to charge 4 x 2500 mAh AA's. A lot of fast chargers will actually take about 6-8 hours, which is too long to be pragmatic. Thus all 2 x AA chargers seem to be out, and only the faster 4 x AA chargers remain.

At present, the Duracell CEF27 (1st generation with curves) seems like the best shot, as I can charge four high capacity AA's in 3 hours (2hrs is for 1700 mAh), which about the same time as what our iPad Mini will take. Unfortunately at 108g it is hardly lighter than the slow charger I have now (115g) and it also appears to block both receptacles on a wall. However anything lighter is substantially slower. The Watson 79g "4 hour charger" sounds promising, but it's rated at 280 min for 4 x AA, which is almost 5 hours and that's likely for 1800-2000 mAh batteries, so my 2500 mAh ones would likely take nearly 6 hours.

Noteable mentions are the Sanyo XX Charger (220 min for 4 AA, 111g), the Panasonic BQ-390 (8-10 hours, but 85g) and Sanyo's 2 x AA Compact USB charger (55g, but much too slow for charging 4). The new generation of Duracell CEF27 is also interesting, as Amazon says its 82g, but it appears to be slower than Gen 1 with a claim of 2.5 hrs for two high capacity AA's.

Brian, this is actually just for my wife and I's headlamps. My camera uses unique Li-Ion batteries, but I have 3 of them so I should be fine there. Opting for NiMH over alkaline or lithium also saves quite a bit of money over the trip, and it avoids being reliant on finding batteries in stores. While not likely a real problem, it's nice to be as in control as possible. Considering I need to charge my camera and iPad Mini anyways, 2-3 hours for charging doesn't really change anything.

http://ww2.duracell.com/media/en-US/pdf/gtcl/Product_Data_Sheet/NA_DATASHEETS/Charger%20Datasheet_CEF27.pdf

Maybe remove the cover for lighter weight?

That's good info and a good idea about the cover. Thanks.

It looks like 4 batteries just takes twice as long as 2 because the max output is 3100mA, so when you toss in 4 the per battery charging is halved from 1550mA to 775mA. Kinda pointless to have 4 slots then in the context of being in a hurry.

Armed with this information, the new CEF27 (called the Duracell Ion 4000) may actually just as fast and lighter at 82g. Is there a product sheet like this for the Duracell Ion 4000? Here's the regular page:
http://www.duracell.ca/en-us/products/battery-chargers/duracell-ion-speed-4000-battery-charger

I don't really trust that 82g weight because the only spot it's listed is on Amazon. And I don't understand how to compare 4000mW of charging (Ion 4000) to the original CEF27 (3100mA of charging).

Dan,
Do you really think you'll need to charge your batteries every week? This seems unlikely to me if you are just using them to power your Zebralight headlamps (unless you plan on lots of night-hiking). I would guess one full charge every two weeks, but you will know your usage better than I will, of course.

With all this in mind though, if I was you, I might reconsider putting the charger in a bounce box (if you plan to take one). You could keep some extra NiMH batteries in the bounce box as well for a quick swap out option in case you are in a rush and need to get out of town. Then, when you get your bounce box again and have more time, you could charge both sets of batteries.

Just food for thought. I'm sure you might have already considered this though…

My wife and I have been back and forth on the bounce box, but we're currently leaning towards not using one. There's a lot of advantages, but it also forces us to plan around the post office hours. There are a lot of downsides to no box bounce, like having to carry chargers and cords, and having to waste resupply items like half bottles of sunscreen, so we're still back and forth.

You make a good point about how much juice we'll really use. My guess is that we'll do some night hiking in SoCal and easily burn through 2 AA's each then, but most of the hike we'd probably use less aside from a few incidents where the headlamps are bumped on in our packs. Maybe a 2 x AA charger would be fine. Unfortunately Sanyo's 55g USB 2 x AA Compact charger takes 6.2hrs for two high capacity AA's which means hanging out in town all day even for 2 batteries.

I purchased the new CEF27 today (Duracell Ion Speed 4000 Charger) with the hope that it would be lighter and ideally faster than the gen 1 Duracell CEF27.

Turns the speed is the same (1550mA for 2 x AA, 775mA for 4 x AA) but it's heavier. The Amazon weight of 82g was way off and it actually weighs 121g. It's too bad I couldn't accurately weigh it in the store because it includes AA's, AAA's, packaging and a manual. It looks like it'll be getting returned and I'll opt for Gen 1.

FWIW, here's the info I've gathered so far:

Dan –

If you are considering a 2AA charger then definitely check out the SolarFocus Battery Charger/Battery Bank that MEC sells. It charges 2AA in 5 hours (according to the doc… depends on the battery density I guess), I’ve not timed mine but that sounds about right.

The big plus is that it’s a battery bank as well with a bunch of different connectors. It can take Lithium disposable batteries (which is what I use) so carrying a few extra AA’s with it allows you to charge your mini etc if needed.

Mine weighs 1.5 oz without batteries and the cable I use (USB to mini USB) adds just under .5 oz so 1.9 oz in total.

Nice thing about MEC is that you can try it and if you don’t like it, no big deal.