Celeron 1037U

[4est]

Iago is correct. In series, the voltages stack (add) and the current remains the same. Also, I would be careful using batteries on a board that is not wide voltage input or in this case, a DC>DC (Pico PS) that is not capable of a wide input voltage. The cells may be rated at 1.2V, but that varies quite a bit upon charge level.

No, the cells are too small. What you are treating as a current is a capacity (product of current * time). Putting multiple cells in parallel would increase their current delivery (because the output current is split over the cells and time is invariant), while putting them in series will increase voltage but keep the current delivery capability constant (the current passes through all cells at the same time). You will arrive at the same result if you calculate energy storage capacity (current * voltage * time) for the circuit.

 

Couldn't you use larger cells (C or D) or maybe a 12V module like they use in model racing? Your board will probably draw 0,5A to 1A steady state and 1A to 2A during boot. Your battery array needs a energy capacity around 20 Wh for useful operation. If you limit current draw to 5% of the (current) capacity 20h * 12V * 0,75A = 180 Wh. That's a small motorcycle battery.

[Animaniac]

Let's suppose I did 3 things

1) Wire 10 in series and 10 in parallel. The cost of these, either Sanyo, amazon basics or GP is so cheap that price is a non-issue. Of course they may vary in sound quality.

http://www.batteriesinaflash.com/images/floodedleadacid/WiringPics/Series_And_Parellel.jpg

 

2) Use a wide input picoPSU

PicoPSU-120-WI-25 Converter | Logic Supply

The chart shows how stable the voltage is, but there is always a chance of 1 or 2 failing. I found a better chart somewhere with 3 voltage curves for 400 1000 and 2000 mA, the difference being that at 400 mA the initial voltage was highest.

3) Use 2 10x battery holders

Battery Holder: 10xAA (5x2) With 5" 26AWG Wire Leads - RoHS Compliant

 

Dan

[iago]

[1] With 10 cells and the pico PSU you are still too close to the lower end of the PicoPSU's specification. You could hope that everything still works with 11.8V or use 11 cells in series. The additional cell's energy is not wasted, because the conversion is switched, not linear.

 

[2] As an alternative, you could use 10 cells in series with a (wide input) board that accepts input voltages from 9V.

 

[3] You could use any number of cells in series with a buck /boost converter in front of the PicoPSU (it will steal part of your charge due to lower overall efficiency).

 

Use as many cells in parallel as your assembly will need. A 2 x 10 Array should give you approximately 2-3 hours of operation.

 

But why don't you use something like this here? It should give you twice the capacity of your home made array. The voltage is lower, but [2] and [3] would work.

 

All of these solutions will fail uncontrollably once the supply voltage is lower than the lowest voltage the board can use. You should either monitor the power supply closely or harden your operation system. This is possibly difficult with Windows.

[4est]

Iago is spot on. That battery is to low of voltage. Find a board/pico PS that works on a lower voltage or find batteries that provide a higher one.

[Animaniac]

Very cool, thanks guys. My mind is more creatively oriented than mechanical so I really appreciate the input. I'd just like to add that the battery pack with US plug can be found here:

http://www.ebay.com/itm/Portable-12V-DC-9800mAh-Rechargeable-Li-ion-Battery-CCTV-B4-2-3-lens-AF100-GH2-/190784564985?pt=US_Cell_Phone_PDA_Batteries&hash=item2c6ba56ef9

 

Getting back to the topic of low power CPUs, here's one with 4.5W TDP

ARK | Intel® Celeron® Processor N2807 (1M Cache, up to 2.16 GHz)

 

I mainly use streaming so this might be good for that.