Power on the go - one practical solution

[allovertheglobe]

To add something constructive to the whole battery discussion:
Besides the Tekkeon wallcharger, I also got their "TekCharge" battery pack (MP1550, $15 at NewEgg, batteries NOT included). Yesterday I loaded it with freshly charged PowerEx 2700mAh batteries. So here's the result (no stopwatch/by the minute count, sorry ):

Start with fully charged DR1000 (Solid green LED)
Light reading for about 5 hours (-> Red LED)

Attach TekCharge (Orange LED)
Continue off and on use through the evening while charging.
DR 1000 fully charged. Remove TekCharge.
Use a couple of bars while it's sitting around for a couple more hours.
Reattach TekCharge & resume charging before going to sleep (Orange LED)
Morning: TekCharge fully depleted, disconnected.
Continue using the DR1000 until completely drained (Red LED, shutdown)
Total: 12 1/2 hours (Yes, really)

Grand Total: 17 1/2 hours of light use without ever turning the DR1000 off or attaching it to a PC or AC. Heavy usage will reduce that time, but I figure one should still get a solid 10 hours+

Sure it's not as elegant as a built-in solution (perhaps DIY soldered for the adventurous) but it is still pretty portable. It even comes with a little velvet pouch.

You can of course use it with regular batteries (which can be found in any airport or convenience store all over the globe). The beauty of using rechargeable batteries is that then the pack ITSELF can be recharged using the same cable and wallcharger used for the DR1000 (not at the same time )

And of course, this solution can be used with any USB device: iPod, Sony reader, GPS... And there are other similar products out there that are probably as good. This is just the one I tried.

On a side note: in light of the usage time with this pack, the built-in battery does seem a bit on the small side...

[pilotbob]

Originally Posted by allovertheglobe

Grand Total: 17 1/2 hours of light use without ever turning the DR1000 off or attaching it to a PC or AC. Heavy usage will reduce that time, but I figure one should still get a solid 10 hours+

Interesting idea. I was thinking you were just going to charge up both, and leave the external battery/charge hooked up to the DR and see how long it would last. I would be interested to know.

While it is "plugged" in if you do this, at least you don't need a laptop or mains outlet close by.

BOb

[allovertheglobe]

Originally Posted by pilotbob

Interesting idea. I was thinking you were just going to charge up both, and leave the external battery/charge hooked up to the DR and see how long it would last. I would be interested to know.

Well, I didn't feel like dragging it around with the umbilical cord attached unless I had to. Besides, between the 2 batteries (internal and external) there is X amount of energy stored and I don't think the timing of when it is transfered around plays a big role. More likely usage will have a bigger impact.

I'll try it when I get around too, but due to the above, I'm not sure how indicative that time will be in comparison.

[dhill]

I was thinking of this also. I have a battery pack that I use for my iPod touch on long flights to watch videos. It's enclosed (not aa or aaa batteries) and can be charged via USB port or USB power supply. I have not had time to test it on the dr yet.

Here's a pic.

[wallcraft]

I think this conclusively demonstrates that the DR has a single cell 1300 mAh battery.

Power from single cell 3.7V 1300 mAh battery = 4.8 Watt Hours

Power from four 1.2V PowerEx 2700mAh batteries = 13.0 Watt Hours

This is consistent with 5 hrs vs 12.5 hrs, and also suggests that the DR1000S is drawing about 1 Watt.

[sarikan]

I am convinced Thanks a lot for sharing it, really a neat way to handle the power issue. The next problem to solve is to find a new and large backpack. With pda+gps+two cell phones, two external drives, webcam, earphone, etc etc.. mine is about to explode
Add DR1000S to the mix (soon), and something will get crushed in it. Any suggestions about this requirement? Actually it would be nice to know if there is a particular brand/model that'd allow us to carry around DR without worrying about damages.

[bob_ninja]

Originally Posted by wallcraft

I think this conclusively demonstrates that the DR has a single cell 1300 mAh battery.

Power from single cell 3.7V 1300 mAh battery = 4.8 Watt Hours

Power from four 1.2V PowerEx 2700mAh batteries = 13.0 Watt Hours

This is consistent with 5 hrs vs 12.5 hrs, and also suggests that the DR1000S is drawing about 1 Watt.

Hmmmm, sounds about right except I am still bit confused:

4.8 Wh = 5h = 1A load, 1W power use

Now adding 13 Wh from AAs:

4.8 + 13 = 17.8 Wh / 1W = 17.8 hrs

Assuming both fully loaded DR battery and 4AAs according to this we should get 17.8 hrs as opposed to 12.5 hrs!!!!

Question: Did you use brand new Powerex AAs? Were they broken in? Did they reach their full capacity?

P.S.: Not sure what is the load while charging. Don't have data for 2700. For 2500 at 1A we get about 2.8 Wh, slightly less than the calculation above.

http://www.candlepowerforums.com/vb/...ad.php?t=79302

[bob_ninja]

Couple of comments:

Powerex 2700 are a great choice. However, if the external battery pack is not used often then you may want to go with LSD type NiMH AAs like Eneloops. Depends on your usage pattern.

I would suggest a decent AA charger like BC900 or BC700

Try not to drain the external pack with AAs completely. AAs will last longer if they are recharged before they are completely empty. Using 2 sets of 4AAs and simply swapping them betwee the pack and charger would work well. That way you never wait.

[wallcraft]

Originally Posted by bob_ninja

Assuming both fully loaded DR battery and 4AAs according to this we should get 17.8 hrs as opposed to 12.5 hrs!!!!

Yes, which is what allovertheglobe found (5 hrs from the DT1000S's battery and then 12.5 hrs from the MP1550, for a total of 17.5 hrs).

[bob_ninja]

Originally Posted by wallcraft

Yes, which is what allovertheglobe found (5 hrs from the DT1000S's battery and then 12.5 hrs from the MP1550, for a total of 17.5 hrs).

Ops, sorry
Read "total" and missed "grand total"
cool

[allovertheglobe]

Originally Posted by bob_ninja

Couple of comments:

Powerex 2700 are a great choice. However, if the external battery pack is not used often then you may want to go with LSD type NiMH AAs like Eneloops. Depends on your usage pattern.

I would suggest a decent AA charger like BC900 or BC700

Try not to drain the external pack with AAs completely. AAs will last longer if they are recharged before they are completely empty. Using 2 sets of 4AAs and simply swapping them betwee the pack and charger would work well. That way you never wait.

I agree. I'm also going to try it w/ Imedion 2100 Low-Self-Discharge batteries. (LSD? watch those acronyms )

I have a very nice 8 battery charger w/ conditioning and all, but I'm not going to haul that one along, so it's good to be able to recharge them on the go in the pack (and it's not quick-charge, so that should be easier on the batteries too)

[bob_ninja]

Sounds like you know what you are doing despite using LSD LOL
One other word of caution. I found + terminals on Imedion AAs to be much smaller than normal cells. I found some battery compartments where Imedion + terminal couldn't reach the contact point due to plastic around + contact!!!

You may want to get few at first and verify they fit properly into the USB power pack.

[bob_ninja]

Originally Posted by wallcraft

I think this conclusively demonstrates that the DR has a single cell 1300 mAh battery.

Power from single cell 3.7V 1300 mAh battery = 4.8 Watt Hours

Power from four 1.2V PowerEx 2700mAh batteries = 13.0 Watt Hours

This is consistent with 5 hrs vs 12.5 hrs, and also suggests that the DR1000S is drawing about 1 Watt.

Yes, Karel confirmed in the iRex forums it is a single 1300 mah (see the other thread).

Now according to these numbers, "light reading" used up interlan battery after 5 hours. Of course, since battery is never depleted fully, I will guess/estimate about 1000 mAh (to be conswervative meaning 300 mAh still left).
1000 mAh / 5 hrs = 200 mA

However, Karel in the other thread stated:
"with software version 1.0 the reader consume about 150 mA per hour"

So once again they seem to be underestimating true power use. Seems like a pattern of overestimating device capabilities.

I suppose battery could be defective or not fully broken in, but highly unlikely. A more likely explanation is that the current software version is still not optimized for power use and subsequent versions might clean up these rough edges.

[Ranpha]

check A Solar , they have backpakcs with solar panels build it and a 2000Mah batteries