Spare battery, Solar Charger or Powerpack?

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  1. tobiasg

    tobiasg Active Member

    Looking forward to warmer weather in the NE US and thinking about nice long bike rides. I am psyched to have such a cool little GPS/computer/map system and plan to take the Droid on long rides. Some will be 3+ hours and I don't want to worry about running out of juice. Researching it looks like I have a few options and wanted to know what you all think. Mostly I think the droid will just sit in my Jersey pocket with screen off but tracking GPS. Occasionally I will check maps.

    I figure my options are -

    1- buy a spare battery - weight- not much, 1300 mAh - Downside, sometime during the ride I will need to swap batteries and restart GPS apps that I might be running. This would be really annoying so I think this is out as an option.

    2- battery extender like Satechi iCel 4400 mAh Battery Extender. Pricey but would certainly give me enough ride time & gets excellent reviews

    3 - Solio H1000 Universal Hybrid Charger Not as much power as the battery extender but I really like the idea of charging while I am out riding, although it seems to charge pretty slowly and needs direct sunlight. Even without serious sun it would probably provide enough of a charge for all but the longest rides. Gets "ok" reviews

    4 - something else?

    I would love advice or thoughts on any of the above, maybe an occasional backpacking trip too.


  2. dakster

    dakster Well-Known Member

    A cheap alternative is the Tekkeon MP1550. It's only $20 on newegg, and takes 4 AA batteries. However, the droid pulls too much juice for disposable alkaline batteries, you have to use some good quality rechargeable AA's. I tried Alkalines, and they just can't do it, they're dead in about 40 minutes (an hot as hell too).

    I use Powerex 2700mah AA rechargeables, got for about $23 for an 8 pack on newegg as well.

    Seems like you can get a full recharge (run the droid battery down, fully recharge it from the tekkeon), maybe a little more out of one set of AA's. You can always just pop in another set of AA rechargeables if you need more than that.

    The mp1550 is also a crappy recharger. I wouldn't use it as my main AA battery charger, but it'll do in a pinch while traveling or something.
  3. tobiasg

    tobiasg Active Member

    Nice! That def seems like a possible solution. I have two sets of the Enloops so I should be good there.

  4. xjestersdeadx

    xjestersdeadx Well-Known Member

    If you're willing to carry the extra weight of a battery charger, then what about the seido extended battery that comes with a larger battery cover? Not sure if it would give you what you need or not.
  5. Psychokitty

    Psychokitty Well-Known Member

    Man, I woul;d really love a backpack made of solar-electro-cloth fabric. How cool would THAT be?
    -Or a solar-electric jacket that's made form a special cloth that can charge up a small camera or phone, flashlight, whatever.
  6. dakster

    dakster Well-Known Member

    The mp1550 weighs pretty much nothing, the weight is 4 AA batteries.

    Just looked it up, the mp1550 is 4.5 oz by itself. I would say that the weight of the 4 AA rechargeables is easily 90% of the weight once the batteries are in there.

    It's also pretty small, there's a good pic in this "review" with the back cover off so you can see the AA batteries:

    It seems to work fine using alkaline batteries for low power draw devices (think anything that draws 500mah or less), but iphones, droids, etc, definitely have to use high end rechargeables.

    Not sure how the eneloops will do, aren't those low discharge batteries? I don't have any low self discharge batteries to test against, so I'm not sure how much current they can handle, but it's probably pretty close to the powerex non-low-self-discharge batteries (pheww).

    I think eneloops are 2000mah, whereas teh powerex ones are 2700mah (supposedly, I think they're more like 2500mah).
  7. Thorpeedo

    Thorpeedo New Member

    I invested in a few back-up batteries but none of them made sense. Then I went for a Solio but it annoyed me that I either had to leave it somewhere or worry about which was it was facing depending on where the Sun was. In the end, I grabbed myself a solar backpack from Infinit. Works great for phone, DS and my GPS, especially when I'm out on my bike. Works in daylight too and even better in the sunlight.

    Got it here: HOME : Infint Solar Powered Backpacks
  8. tjreishus

    tjreishus Well-Known Member

  9. PhotonLight

    PhotonLight New Member

    Yes, the eneloops are 2000mah. PowerEx's Imedion line of batteries are comparable to the Eneloops though and rated at a slightly higher 2100mah. The term "low discharge" might be a bit confusing, but basically it means they have low self-discharge and retain their charge for longer when stored away, unused. Normal rechargeables will lose something like 15% of their charge after two months in storage. Eneloop, PowerEx Imedion & other similar types claim to retain up to 85% of their charge after a full year off the charger. It's good for situations where you won't be using the batteries for a long time but want to ensure that they will still have a good charge when you do use them, but they sacrifice a LOT of capacity in exchange for that peace of mind. They should handle powering high-drain devices just as well as normal rechargeables though. Personally, I use the Imedions in things like Wii controllers & TV remotes, but if they're going in something I use regularly the higher capacity of the normal rechargeables makes them a better choice.

    Also FWIW, as far as actual useable capacity ratings go, we tested a number of batteries from different manufacturers when we were first looking into carrying PowerEx products on our site and found that unlike most manufacturers who tend to be a bit optimistic with their capacity ratings, PowerEx tends to rate their batteries very conservatively, so the stated capacities are actually pretty accurate. In fact, the Imedion AA's we tested turned out to be closer to 2200mAh.

    PowerEx Imedion 2100mAh AA
    PowerEx 2700mAh AA
  10. SAFE_2006

    SAFE_2006 Active Member

  11. skunkpbguy

    skunkpbguy Well-Known Member

    I've been looking into kinetic chargers.. but it seems the dozen or so that have been developed are not produced anywhere. To me a kinetic charger would make life much more fun for my Droid, with all the walking I do at work, my battery would never drop below 60%. :)
  12. dakster

    dakster Well-Known Member

    Thanks for that post, I always wondered about the low discharge ones and how well they would handle a high load.
  13. DuckHunter

    DuckHunter Active Member

    I'm going backpacking this spring and this thread is something I've been thinking about lately. I think I've decided to go with the Tekkeon TekCharge MP1800.

    The 1550 is the model that uses AA batteries, but I don't want to have to carry a bunch of batteries with me so the 1800 looks best for my use. The reviews on Amazon were very positive as well, so that makes me feel better about it. I plan to order in the next few days and I will reply with my opinion after I test it out.
  14. tobiasg

    tobiasg Active Member

    Great ideas. Still really leaning toward the Tekkeon 1550, it is cheap, I already have solid AAs, in addition to the enloops I have some older PowerEx 2200mah and some newer energizer 2650mah. It is not as exciting as some of the solar powered options but seems more practical.

    Looking forward to hearing from Duckhunter too.

    The Dahon thing needs to be hooked to a generator hub - those are pricey and somewhat of a pain to deal with. I do dream about riding across the country one day, would be something to look into in more detail then.
  15. wsbsteven

    wsbsteven Well-Known Member

    The solar solutions mentioned really aren't very good. I'll offer another solution that goes for around $30 if you can find it.

    PowerSource Mini | Portable Battery Charger | Duracell

    Has 2 usb connections, a 3Ah battery, can recharge using a computer, and weighs less than the Droid.
  16. PetiePal

    PetiePal Well-Known Member

    Solar is a waste of time for how long it takes to charge. You're too reliant on sun or being outdoors etc anyways. You're better off going for 1 or two portable rechargeable juice deliverers. Don't go with AA battery devices, you'll burn through them too quick even the rechargeables. I have 2 Kensington mobile device ones that I charge up, both about as thick as a pencil and about the size of a credit card. They were perfectly.

    Dell makes their own brand but I haven't heard amazing things about them. You'd want the largest capacity one they made anyways.

    This one is 1150mAh
  17. PhotonLight

    PhotonLight New Member

    Hard to say since specs in the description are limited, but assuming it's 1150mAh @ 5V (standard USB voltage), that's somewhere in the neighborhood of 5.75Ah, so should be good for about 1 full charge (I believe the Droid's battery is about 5Ah). For comparison, two fully charged 2700mah AA's would probably provide a similar amount of charge. That Duracell charger sure looks slick though.
  18. tobiasg

    tobiasg Active Member

    Searching the reviews of the Duracell charger shows one Droid users who isn't toooo happy with the amount of power provided. But I agree, it does look very slick!
  19. hotzorro

    hotzorro Member

    I bought the "Just Mobile Gum Pro USB iPod External Battery 4400mAh" and am VERY happy with this. It has the most juice I could find, is small and compact and will add huge amounts of time to your phone use. In fact, it has enough juice to actually charge the phone 100% when completly dead while you continue to use it.

    I personally got this for the golf course...I want to use my GPS app for the full 4 1/2 hours without turning it off.....and this will do the job.
  20. Zbig

    Zbig Well-Known Member

    I just got myself one of those today too. Now I'm waiting for it to recharge (it already takes 7 hours...). As soon as it's fully charged I'm going to discharge it with my R/C hobby charger measuring the capacity delivered. As far as I can tell from the dimensions, shape of the case and its weight so far, it packs two Li-Ion cells of the 18650 industrial standard form factor (the same as used in many laptop batteries) so at least it has potential to really deliver something in the declared 4.4Ah range which should theoretically yeld some two full Hero charges.

    I don't recommend any but some really bad-ass solar chargers for some serious smartfone use other than "just for one emergency call" scenario. The pocket ones tend to have internal battteries a little on the smallish side, have a really hard time delivering the current required and it takes ages to recharge them in the other than middle-of-Sahara environment.

    And don't compare apples to oranges, guys - you cannot directly take mAh figure from AA rechargeable battery (1.2V), phone battery (3.7V) and just compare them. You have to convert both to watt-hours first and take the voltage converters' efficiency on the both sides into account. So, for the 2xAA Eneloop-equipped battery pack, that would be:

    2 x 1.2V x 2Ah (assuming Eneloop) = 4.8Wh (Watt-hours)

    Then, assume the step-up switching mode voltage converter (2.4V->5V) efficiency of 80% and you get some 3.84Wh. Then, you have another voltage regulator on the charged (phone) side (5V -> 3-4.2V). Assuming 80% efficiency for that one too, your chances of pumping into the phone any more than 3Wh (64% of the initial Wh calculation) are quite slim. Hero's battery, for example, holds some 1.35Ah x 3.7V =~5 Wh so you'll get some 3/5 of the full Hero charge from two fully charged Eneloops.

    Furthermore, beware of the 4xAA "chargers" not equipped with the voltage converter of any kind. Some of you guys mentioned some 4xAA charger which is very light and most probably it's of that very kind. I have one of these and it's nothing more than a case for 4 AA cells connected in series and a switch. This will give you the required 5 volts on the USB connector only in the initial stage on the fully charged batteries at best. Then the voltage will drop soon and your phone will either charge seemingly forever, stuck on 99%, time-out, freak out, spit out some "incompatible charger" message or anything in between. Beware of that cheap stuff.

  21. PhotonLight

    PhotonLight New Member

    True. I was actually thinking of the 2700mah PowerEx AA's when I was doing the Wh math, which actually comes out quite a bit higher. Good point about the losses from step-up switching, etc. though. I hadn't considered that part.
  22. tobiasg

    tobiasg Active Member

    Still thinking about this - really like the reviews of the Just Mobile Gum Pro USB iPod External Battery 4400mAh except the mentioning of the on off switch being flimsy and causing issues, I am hoping to throw this device in a bike jersey pocket and not worry about it getting jostled a little.
  23. DuckHunter

    DuckHunter Active Member

    Got a Tekkeon 1800 purchased on Amazon.

    It charged my DROID from 20% to full in 90 minutes. Not bad I thought!
    The Tekkeon came mostly charged (more than 60%). After charging the DROID, it was down to about 30% left so I now have it charging on USB at the computer. It is small and light. Perfect for what I need it to do... keeping my Droid charged over a three day camping trip where the phone will mostly be used for texting.

    So far it does seem slow to recharge. I'm going to leave it overnight.
  24. Zbig

    Zbig Well-Known Member

    Ok, so here are some initial observations on my "Gum Pro" (oh c'mon, who came up with that name... ;)) device I got recently.

    First of all, my Gum Pro wasn't able to provide the declared 1000 mA of current on the USB output. When loaded at 1A with R/C hobby charger in the discharge mode, the "Gum" shut itself down immediately. When I went with the loading current down to 0.5A, it still didn't deliver full 5V but something in the 4.72V range instead. So much for recharging my Hero at full AC adapter rate... Capacity-wise though it performed well, shutting itself down after delivering 2815mAh@4.72V which accounts for a little over 13Wh of usable power so I'm happy with that as it's more or less as much as to be expected from the declared 4400mAh@3.6V battery capacity. Recharging the thingy fully from a powered USB hub took eons (7 hours or so) and I'm yet to see if the things change when using AC USB adapter I got with Hero.

    One note regarding recharging: there's a bi-colored LED which is supposed to switch from red to green once the charging is complete. The problem is, that the circuit designers cut some corners and it seems not to actually switch colors but rather start with both green and red lit and then gradually fade the red component down to zero as the charging goes on. So, you have to look at the LED at the "right" angle to be sure it's "just green" already and not "green-red" still :) Kinda stupid but not a deal-breaker either.

    It has just finished charging my Hero from 4% to 100% in some 2 hours and 15 minutes (2 of the 3 meter LEDs still lit) so while not as fast as using the supplied AC adapter, not really that bad either. So, given the really good price-to-capacity ratio I think I can live with the lower than advertised maximum current and can recommend this product to anyone who doesn't need as-fast-as-possible recharging performance.

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