Do you really need a buffer battery?

[Danneaux]

Hi All!

I am often asked if I use a buffer battery with my Tout Terrainn The Plug 2 and P.A.T. amplifier cable.

The answer so far has been "no, not yet". This will all change the day I take a computer with me. Its greater energy needs cannot be met with my current (sorry) setup, and will require a buffer battery. I have been a bit resistant to take a buffer battery because it adds both weight and bulk. If it is of high-capacity, it provides a lot of juice for a long time. The downside is that energy-dense batteries take a long, long time to recharge from empty with an on-bike charger when away from the mains for an extended period. Therefore, one has to adopt a trickle-charge strategyto keep them topped-off.

The other side of the argument is...if the buffer battery has sufficient capacity and USB outlets, one can take fewer dedicated batteries, charge off the buffer battery as you go...and have a bit of reserve before you have to charge, from the bike or a wall outlet.  Of course, most of the drawbacks of a buffer battery go away if you remember to recharge the buffer from the mains while at a motel. It is when one is away from mains power for extended periods that the good and bad of a buffer fully emerge.

Meanwhile, I'm topping-off my batteries as I ride and using my AA/AAA batteries as my mini-buffer for replaceable batteries (Eneloops and Sony-branded Eneloop with high Amp/Hr ratings and an Eneloop AA/AAA charger. Dense batteries last longer but take longer to recharge), then charging my embedded batteries as I go. It takes about two to four hours' riding to fully recharge a depleted pair of AA/AAA batteries with my setup. Any gadget whose charge ratings are based on 1A charging rates will take twice as long when filled with by 0.5A source like The Plug. I chose gadgets with really good battery life whenever possible, and with USB charging. If they didn't allow USB charging, I made my own adapters to do so after checking on power requirements:

Items using AA batteries (two of my my most important items):
= GPS (2AA, usu. start with Lithiums, then switch to Eneloops; can be powered in real-time with Dan-hacked power cord to The Plug)
= SteriPen water purifier (4AA). I went with the Classic for the AA cells...the RCR123's take a lot longer to charge but are more energy-dense; a tradeoff for a more common size.

Items using AAA batteries:
= Auxiliary LED blinky taillight (2AAA, 30/65 hrs' use)
= LED headlight (for me to wear around camp, 3AAA, 115 hrs' use)
= AM/FM/Weather radio (1AAA, 12-54 hrs' use)

Embedded (not user-changeable):
= Panasonic electric shaver (holds charge good for 2 weeks' shaving, eliminates need for water). Dan-hacked USB cable.
= MP3 player (Li-Po, good for 11hrs' use).
= GoPro camera (changeable, but I charge in-camera to save the weight of another charger; carry 3 charged spares. Battery life varies greatly depending on 720 vs 1080 video, and LCD back use)
= Samsung/Flip Mino vidcam (good for an hour on each charge)

Other:
= Cell phone (an old 3G "dumb" phone that almost always connects if it is at all possible to do so). Another of my most important items. Batteries charged in-phone, with at least 6 charged batteries on-hand. Phone is my lifeline. Dan-hacked USB cable.
= Chinese eBay clip-on USB charger for my other digicam/vidcam combo, with 6 charged spares, since this is my primary camera.

Carry:
= 3 1A USB "micro-cube" wall chargers and a threaded bulb socket-to-AC plug adapter so I can charge where there is a light bulb, 1 1A/2A USB charger for an automobile lighter/charger socket so I can quick-charge off a motorist's system if necessary.
= Reel-type USB cord with assorted ends to fit my gadgets, plus Dan-hacked adapters where none were available (GPS, phone, shaver).
= Charged spare batteries for my gadgets. How many depends on energy consumption, use, and critical need. The phone gets first priority, followed closely by the GPS (the two spare compasses I take require no power at all). The water purifier can be swapped-out in favor of chemical treatment or boiling.

So far, if I leave home with the items fully charged and any spare batteries fully charged, then swapping the depleted items onto The Plug or topping off at the rare but occasional restaurant or motel with the 1A wall chargers does the trick. The "big" items to keep going are the Phone, GPS, and water purifier. Everything else I coud get by without, so I assign lower priority in the charging queue.

Add an iPad or similar carry-along computer "someday", and I'll need to go the buffer-battery route, no question. The trouble is, the buffer battery adds both weight and bulk if it is of sufficient capacity to really count. The good news is if it has a USB output, it can charge everything else as well, minimizing the need to carry as many individual spares.

Best,

Dan.

[rifraf]

G'day Dan,
I'm slowly following in your tyreprints with regards to trailer charger.

My Ogre is mostly finished and I'm really just ironing out the niggles now trialing different tyres and grips etc.

My trailer wheel is getting built as I type - I dropped off a Son28 hub and rim/spokes to a LBS last week and hopeful I'll get the call to pick up this week.

Currently trying to negotiate a better solution than ordering a trailer frame and then having to order new attachment "forks" of a 29er nature for it at added expense.
My belief is that they should stock factory 29er trailers instead of an add on sale for an extra $85.
I mean what the hell am I supposed to do with a set of 26er trailer forks that don't fit my bike? - lol.
We try these things.

Anyway you may be able to steer me in the right direction.
I've bought a battery without looking hard enough at the spec due to being overawed by its 23000mAh size.
http://www.ebay.com.au/itm/151167271530

It has yet to arrive but I notice that its input is rated at DC 15 - 20V 1.2A

Charging current From Wall:   1.2A (Max.)

My E-werk has a max output of 13.3V and 1.5A

What do you think my chances are of the E-werk trickle charging at the lesser voltage set to 13.3 and 1.2A?

Another  seller was selling a 16000mAh version which I noticed came with a car cigarette adapter rated at Car DC /DC 12~24V 2A charger  here:
ebay.com.au/itm/16000mAH-High-Capacity-Solar-Charger-Battery-F-Laptop-Iphone-ipad-Samsung-Galaxy-/181179922815

I don't know enough about electricity to proceed further.
My intention was to utilise the trailer to charge an iPad and hopefully do something with my Nikon camera batteries via a storage battery like the above with the addition of the solar trickle charge.

I use another Son28/E-werk buffer battery/E-werk for a front wheel setup  on my bike to charge my phone/gps and my lights (Edelux and Philips Ringlight) which I've been extremely happy with.

Any thoughts?

[Danneaux]

Hi Rif'!

Good to hear from you and to follow your project as well. I agree it would be terrific to get the Extrawheel Solo attachment fork you need the first go; currently the factory store only lists it with the Universal Fork (20-26") or the wider 26x3.7" fork intended for Surly's Pugsley fat-bike. That 29" fork is extra (I got one too; as you say, "We try these things").

I've bought a battery without looking hard enough at the spec due to being overawed by its 23000mAh size.

Wowzers!   That is twenty-three-thousand milliamp-hours! Man! Light a house with that thing!  

Charging current From Wall:   1.2A (Max.). My E-werk has a max output of 13.3V and 1.5A. What do you think my chances are of the E-werk trickle charging at the lesser voltage set to 13.3 and 1.2A?

On the face of it, not good...something may well go in, though I don't think it will be enough to make up for demand in a very timely manner. Huge storage batteries are a wonderful boon 'cos they provide either more juice or for longer or -- sometimes -- both (given enough capacity). The downside? They take a long time to recharge by solar or bicycle means...not so bad by mains power, which sometimes occurs at double the bike-generated rate (i.e. 1.0A from mains source instead of 0.5A/500mAh typical from the bike). Even so, the math says this would take better than 19 hours to charge from flat on mains power. With the e-Werk cranked on high? Well, trying to charge big batteries with it is on my list of things to do, so I'll be following your tests avidly. So far, I've just used the trailer's e-Werk charger as if it were another The Plug2+ to keep the less demanding gadgets charged (AA/AAA cells, camera batteries, shaver, etc).

Rif', since writing the post previous to yours in this thread, I've started carrying a Joos Orange solar panel and accumulator battery combo described more fully in this thread: http://www.thorncycles.co.uk/forums/index.php?topic=7663.msg49485#msg49485 Unfortunately, I have not yet had the chance to see if the Joos Orange will actually charge from either the bike's front wheel dynohub-charger (SON28 New and Tout Terrain The Plug2+) or the Extrawheel dynohub-charger (SON28 Klassik and B&M e-Werk). I'm eager to give it a go.

By the way, the Joos Orange has "only" a 5400mAh battery, according to the published specs -- and its case size is slightly larger than your new battery. The Joos has only about 23% the capacity of yours, and it tops out at 5.0vdc output @ 1.0A. They claim...

The JOOS Orange battery is roughly 80% the size of the iPad 1 and iPad 2 battery, and about half the size of the “new iPad” battery. Because of limitations with the charging circuitry on Apple’s iPad, some power is lost during the charging process. This results in the JOOS Orange providing a 60-70% charge on an iPad or iPad 2, and a 35-40% charge on a “new iPad.”

I've only used mine to (re)charge less demanding gadgets and AA/AAA cells so far. Looking at your new solar/battery combo (still stunned by that rating...), they're getting a lot of energy density out of such a physically small package. I checked the measurements and it is slightly smaller than my Joos Orange solar/accumulator battery combo. I'm not sure how they're getting 23000mAh or how a solar panel that size will charge it. In a similar-sized package, the PowerMonkey Extreme has a 9,000mAh battery and charges from solar in about 15 hours (@ 0.5A or from mains power in about 7 hours @~1.2A or so).

I don't think the solar panel is going to do much in terms of charging that big battery from flat in a timely manner; I think it may be better suited for topping-off a charge or keeping up with (limited) demand. I fear the same for your dynohub-e-Werk combo, but it may work better in practice (depending on the circuitry) if you can combine your dyno-power with solar, but it will take awhile. To make much of a dent even with the e-Werk set at 13.3VDC @ 1.5A, you're going to have to keep the kettle on the boil, speed-wise. I hope it will work, as your battery's 19VDC output has the potential to charge my own little netbook.

I also use a small 5vdc @ 2200mAh buffer battery between my Tout Terrain the Plug2+ and my GPS when I am continuously recording tracks for an extended period of time. More about it and my Joos Orange setup here: http://www.thorncycles.co.uk/forums/index.php?topic=7119.msg45123#msg45123

Please tell us you impressions when the unit arrives and let us know how your testing goes. I'm really eager to see how you fare and hope this will work out well in practice.

All the best,

Dan.

[il padrone]

Looking at the pics rifraf, that panel is about the same size as one half of the Powermonkey's split panel.





Charging a 23,000 mAh battery? "Tell 'im he's dreaming!!"


I can't see where this mega-monster battery is. Don't tell me it's supposed to be in the same case as the panel  

[rifraf]

Looking at the pics rifraf, that panel is about the same size as one half of the Powermonkey's split panel.


Charging a 23,000 mAh battery? "Tell 'im he's dreaming!!"


I can't see where this mega-monster battery is. Don't tell me it's supposed to be in the same case as the panel  

G'day IP,

You could be right for all I know , though }SkOrPn--7 on the Australian cycling forum says good things about his one and I've had good luck with his tips and advice so far.
He does seriously long leg tours on his recumbent trike and trailer combo and from memory is currently in Northern Queenland, away from his home in South Australia.

There are some pics of his down the bottm of this thread:
http://www.bicycles.net.au/forums/viewtopic.php?f=2&t=50649&sid=25b5b05d253f6d75a14733eb5cb01bcb&start=175

Hes had both versions, sold as the 16000 and now the 23000mAh respectively

Grabbing dimensions from another auction of what appears to be the same product:
http://www.ebay.com.au/itm/12V-16V19V-23000mAh-solar-laptop-charger-for-Phone-Notebook-Tablet-Laptop-Pad-/390562623910

Dimension: 222x126x21mm
Weight:649g
Charging time: about 8h for DC Charging

What seems like some positive feedback on Amazon

http://www.amazon.com/EvikooTM-Mp-s23000-23000mah-External-Rechargeable/dp/B00ABTIGMO/ref=sr_1_1?ie=UTF8&qid=1384685919&sr=8-1&keywords=MP-S23000+solar

http://www.amazon.com/XTPower-MP-S23000-Power-Bank-MP3-Player/dp/B00A34T7HU/ref=sr_1_2?ie=UTF8&qid=1384685919&sr=8-2&keywords=MP-S23000+solar

http://www.amazon.com/Allpowers%C2%AE-23000mah-Charger-Cellphone-Nintendo/dp/B009C5Z0IG/ref=sr_1_3?ie=UTF8&qid=1384685919&sr=8-3&keywords=MP-S23000+solar


There appears to be a few different versions of the power monkey.  Which one did you want to compare it too?

https://www.powertraveller.com/en/shop/portable-chargers/outdoor-adventure/powermonkey-extreme-5v-only-version-1:1/

"The powermonkey extreme unit weighs 242g and measures 152 x 59.5 x 28mm, whilst the solar panel weighs 214g, measures 171 x 90 mm and is 18mm deep when folded."

Appears to be a noticeable weight difference.

If I find it below par, I'm happy to revisit my purchase decision and reconsider the Power Monkey Extreme.

[il padrone]

Grabbing dimensions from another auction of what appears to be the same product:
http://www.ebay.com.au/itm/12V-16V19V-23000mAh-solar-laptop-charger-for-Phone-Notebook-Tablet-Laptop-Pad-/390562623910

Dimension: 222x126x21mm
Weight:649g
Charging time: about 8h for DC Charging.....


......https://www.powertraveller.com/en/shop/portable-chargers/outdoor-adventure/powermonkey-extreme-5v-only-version-1:1/

"The powermonkey extreme unit weighs 242g and measures 152 x 59.5 x 28mm, whilst the solar panel weighs 214g, measures 171 x 90 mm and is 18mm deep when folded."

Appears to be a noticeable weight difference.

Yes those are the dimensions for the Powermonkey Extreme that I have, so that unit you've bought has a good bit larger panel, and a heavier unit too. The battery I presume. 1.5 times the weight, so double the charging output is reasonable, not sure about 2.5 times with 23,000 mAh. You may be right with it.

[rifraf]

Yes those are the dimensions for the Powermonkey Extreme that I have, so that unit you've bought has a good bit larger panel, and a heavier unit too. The battery I presume. 2-3 times the weight, so 2-3 times the charging output is reasonable. You may be right with it.

Fingers crossed it will do a turn.
I"m regarding it as a compromise due to current financial priorities.
I've just bought/in process of buying a new overhead tarp, Mondial tyres (after your recommendation), new dynamo tail light, tent footprint, iPod, extra-wheel trailer and a large assortment of gear in anticipation of some extended touring in 2014.
The coffers are a little lite and I thought I'd take a punt.
I'll wear the derision if its falls flat

[mickeg]

Dan, what brand and model is your weather radio?  And does it have a speaker or do you need to use headphones?

For weather where I am far from civilization I use a marine band handheld radio that takes 6 AA batteries.  Quite heavy for the small amount of time that I actually listen to it.  This year to cut some weight on my annual canoe trip, I used AAA batteries in plastic AAA to AA adapters, but it is still large and heavy. 

[Danneaux]

Dan, what brand and model is your weather radio?

Sony Walkman SRF-M37W, ~USD$29 at Wal-Mart, but be aware I found not all examples are created equal. I love mine, though.

And does it have a speaker or do you need to use headphones?

No speaker included, but fairly large headphones are. They were too bulky for me, so I use an older pair of Sony's earbuds that work very well for my needs when paired with a Radio Shack inline volume control (needed not for sound but to boost sensitivity; see below). There is always the possibility of a tiny plug-in speaker. Some of these add very little weight. The radio itself is remarkably small and light.

One caution, however: The radio's circuitry is designed in such a way that sensitivity seems to be dependent on volume. I have good ears and want to keep them that way, so I run my radios at minimal volume. On the SRF-M37W, there is a huge step at the very bottom of the volume range where all audio fidelity drops off -- and so does sensitivity. It is not as noticeable with the huge, '80s-style headphones supplied with the unit, but with earbuds, it is horrible. The solution is to run the unit with an inline volume control ( http://www.radioshack.com/product/index.jsp?productId=2102975 ) so the radio volume can be turned up above minimum while maintaining a reasonably low listening level at the earbuds.

Thread on the topic is right here, mickeg: http://www.thorncycles.co.uk/forums/index.php?topic=4023.0
Post devoted to the Sony is here: http://www.thorncycles.co.uk/forums/index.php?topic=4023.msg18320#msg18320

In practice, the little radio has proven itself nicely for Western US use (there is a step-offset for Europe butno weather there) and the battery life on a single AAA cell is phenomenal (I use Eneloops I recharge from my dynohub). I have taken it into box canyons and other "radio-challenged" locations and found it can get reception when my other radios can't. Unfortunately, the weather band can be the most difficult to receive sometimes because of the low-power transmitters used, not the radio.

Best,

Dan.

[Andre Jute]

I'll wear the derision if its falls flat

We're laughing with you, Rif. Honest.

Seriously, we're following this avidly. You're on the right place, where we're used to having someone lead the pack on some of the most unlikely components that a year later, after being proven, is suddenly the standard at the cutting edge, to mix a metaphor or three.

That said, I know a little about electronics -- at the high voltage end, see Jute on Amps -- and, as Dan and IP have said already, the math and the mass don't seem to add up right unless there has been some magical, secret advance in batteries. So, on the one hand it will be great for us if a sensible chap proves it works, but don't be too downcast if the laws of physics catches up with the marketing hype.

[JimK]

I would really like to understand batteries better! Ratings are strange: amp-hours. That is not the same as energy! To get an energy requires a voltage, too. I.e. amp-hours at what voltage? Of course the voltage varies with the state of charge, but still, some sort of ballpark number would be nice.

Batteries are usually built up by putting cells in series. Each cell puts out maybe a volt or 1.5 volts, depending on chemistry. So you can put maybe 4 in series to build up to 5 volts. The same current flows through each when they're in series like that. Or you can put them in parallel and get 4x the total current but of course just the boring 1.25 volts. Same power/energy, just packaged differently.

Looking at the battery specs on amazon, it can run at different voltages. Got to be the case that the mAh rating will vary, roughly inversely proportional to the voltage. I couldn't see which voltage gave that 23000 mAh rating. So there is a bit of an awkward gap right there. But I am not up on all the conventions for ratings, etc. - the gap could easily just be in my understanding!

[il padrone]

I would really like to understand batteries better! Ratings are strange: amp-hours. That is not the same as energy! To get an energy requires a voltage, too. I.e. amp-hours at what voltage? Of course the voltage varies with the state of charge, but still, some sort of ballpark number would be nice.

W = V x A

Power (watts) = Speed (volts) x Flow (amps)

I think I have that right. So amp-hours is the flow per hour.

[JimK]

W = V x A
Power (watts) = Speed (volts) x Flow (amps)
I think I have that right.

Volts doesn't really map well to speed! If you think of electricity being like water, then amps is flow like gallons per hour, and volts is like a difference in height. You can inject power into the system to pump water uphill, or you can let it flow downhill and extract energy.

So amp-hours is the flow per hour.

Amp-hours is flow TIMES time. So amp is to gallons-per-hour as amp-hours is to gallons. An amp-hour is 3600 coulombs, if that helps!

[macspud]

What seems like some positive feedback on Amazon

http://www.amazon.com/EvikooTM-Mp-s23000-23000mah-External-Rechargeable/dp/B00ABTIGMO/ref=sr_1_1?ie=UTF8&qid=1384685919&sr=8-1&keywords=MP-S23000+solar

http://www.amazon.com/XTPower-MP-S23000-Power-Bank-MP3-Player/dp/B00A34T7HU/ref=sr_1_2?ie=UTF8&qid=1384685919&sr=8-2&keywords=MP-S23000+solar

http://www.amazon.com/Allpowers%C2%AE-23000mah-Charger-Cellphone-Nintendo/dp/B009C5Z0IG/ref=sr_1_3?ie=UTF8&qid=1384685919&sr=8-3&keywords=MP-S23000+solar

Going by that feedback I'd not buy it.

[Andre Jute]

Amp-hours is flow TIMES time. So amp is to gallons-per-hour as amp-hours is to gallons. An amp-hour is 3600 coulombs, if that helps!

You could think of the amp-hour as the battery supplying 1 amp for 1 hour at the rated voltage. In fact, absent some control device, the actual voltage will start higher (up to a fifth should cause you no concern) and end up a small fraction of the total voltage rating below the rated voltage when the battery is "flat". That's the theory. In real life it isn't that simple by far. In real life you have consider how much current the battery can deliver constantly without ruining the cells, without overheating, etc, etc. An idealized rating of one amp at best means that you can draw perhaps three-quarters of an amp from the battery. Whatever the "peak" rating may be described as technically, if you tried to operate tha battery at such a draw, you'd wreck it on day one. If life and limb will depend on these bicycle/solar chargers, I suggest you learn about the C factor in batteries, which describes how fast they can/should be discharged.

I had a good deal of experience in vacuum tube hi-fi, where I would operate the grids of tubes in autobias on penlight batteries which performed several crucial functions at once, so that tens of thousands in irreplaceable equipment would depend on a single battery, and never lost more than a couple of hundred dollars worth of gear, but when I investigated larger batteries, when I installed an electric motor in my bike, I was shocked at how complicated and uncertain battery "science" is. I wish you luck.

My plusses want to party with your minuses...