More Power!

No, not Tim the Toolman type of more power (thought that’s never a bad thing), but something more mundane. As a photographer in today’s digital camera world, knowing the state of charge of your batteries is essential and while most cameras provide a fairly good indication of the state of charge of your battery, it’s never all that accurate. Additionally, spare batteries that you carry with you can be hit or miss as far as charge goes, if you haven’t had them on a charger for a while. Sadly, the majority of chargers don’t provide an actual voltage readout, merely showing a light when the battery is charging/charged. This isn’t always a good thing.

Tool Time - (source: News Corp Australia)

Tool Time – (source: News Corp Australia)

Also, OEM as well as aftermarket chargers (which can have their own foibles) aren’t always a convenient thing to use, requiring 240V power. So a while back I discovered and bought an aftermarket eBay charger that runs off a mini-USB port (the type typically used to charge mobile phones), which means that it can be used with greater ease, not necessarily requiring 240V power. I had some initial reservations, but the charger actually works very well but, again, doesn’t show voltage; I don’t know why this isn’t done, rather than showing charging bars on the LED screen. Anyway, always in the DIY state of mind, I realised that I had all the bits and bobs to make a useful battery voltage tester (rather than using a voltmeter as I have been doing).

Top-Max Battery Charger

Top-Max Battery Charger

Voltmeter

Voltmeter

The voltage tester came about because I had an older aftermarket battery charger, similar to this eBay one, that would no longer charge and so couldn’t be used, and I had a spare eBay LED panel voltage meter that I’d bought a while back for another application, so it looked like the two could be melded together. Thus began another little project, putting to use unused stuff that was just lying around. I always seem to have unused stuff lying around. BTW, I could have done similar by just using a set of Voltmeter cables attached in a similar way to what I’m about to describe, so you don’t really need the digital gauge I’m using.

Useless Battery Charger

Useless Battery Charger

Panel Voltmeter

Panel Voltmeter

The first step was to disassemble the battery charger, which only required a small screwdriver and the assembly was in three pieces in minutes.

Disassembled Battery Charger

Disassembled Battery Charger

The base of the battery charger was almost identical in size to the voltmeter panel, with a smaller internal form housing clips designed to hold the meter in an instrument panel. So all that was required was to cut a hole in the base of the battery charger housing with a Dremel style tool, some filing to get the hole neat and tidy and the LED panel slotted in perfectly. Once that was completed it was a simple matter of soldering the corresponding wires from the battery charger housing to the LED panel and the job was almost done.

DIY Battery Voltage Tester Assembly

DIY Battery Voltage Tester Assembly

Then it was a matter of putting the two battery charger housing components together, though I could no longer use the screws, and that was it. I thought about using some plastic glue to join the housings, but then if I ever wanted to get at the innards again, I’d have a devil of a time separating the two housings, so I opted to use some electricians tape instead. It’s not quite as tidy, but it does the job and covers up the holes left from the removal of the internal circuit board of the battery charger.

DIY Battery Voltage Tester

DIY Battery Voltage Tester

DIY Battery Voltage Tester

DIY Battery Voltage Tester

So with everything together, it was just a matter of testing the unit out. I did test that everything worked before joining the two housings, as it would have been pretty dumb to put it together, only to have to separate things again because I’d missed something. As it is, things worked perfectly and it came out as a fairly neat little unit. Now all that I need to do is get a feel for how much battery power ie, how many shots are left at what voltage levels, to make best use of this tester. As I said at the beginning, I have no idea why a proper voltmeter isn’t included in every battery charger as it makes charging more reliable and you can tell how things are going while charging. Knowing such means that you can remove the battery and know that you’ve got enough charge if caught short for whatever reason.

DIY Battery Voltage Tester

DIY Battery Voltage Tester

Additionally, I recently acquired a Bauhn 7200 mAh Li-Polymer solar-powered power-bank from one of our local Aldi stores for $20. Now while you can get more powerful ones on eBay, for slightly more, if this one doesn’t play well, it’s all too easy to return it. And while battery technology has advanced in leaps and bounds in the last few years, I am still a tad sceptical that you can get a 50,000/80,000/100,000 mAh power-bank (as claimed) in a package that’s only 3mm thicker than this one and otherwise exactly the same size. Also, as the solar panel is only capable of providing a maximum of 180 mAh of charging power, it will need to be under full sun for some time to fully charge even a 7200 mAh battery, let alone a 50,000 mAh battery.

Bauhn Solar-Powered Power Bank

Bauhn Solar-Powered Power Bank

To complete the circle, I also bought a inexpensive USB voltmeter from eBay so that I can manage the charging more efficiently, as alluded in the main part of this story. It is perfect for understanding how much charge is being delivered and when the charging has actually finished. In fact it supplements the voltage tester, as it records how many mA are required to raise the voltage from battery low to fully charged,

USB Voltmeter - (source: eBay)

USB Voltmeter – (source: eBay)

Solar power is appearing just about everywhere nowadays, as the technology has effectively matured (though there is still constant development going on in an attempt to gain greater efficiency) and portable power development is being driven by our insatiable need for power due to all of our modern day electronic devices (the military is very much into man-portable power generation). One of the issues with modern devices is that you’re not always going to have 240V or 12V power available for charging your devices, so having a portable power source that can charge itself during the day isn’t such a bad idea. How many times could I have made use of one of these, years back while attending endless meetings, where everyone scrambled for a power point?

Cables everywhere - (source: displaynote.com)

Cables everywhere – (source: displaynote.com)

The only thing that would have made this device even better, were if it had a retractable cable like the Nokia power-pack shown earlier (the day-glow orange one). That would really save on needing to have a separate cable on hand (considering that many/most devices now use the micro-USB plug). At the moment, I have no idea as to how well this device will work in the long-term and how consistent it will be, but if it does perform reasonably well, it’ll be a great item to have around when travelling. In fact, when I’m on one of my bush trips, I’m invariably short of one USB charging port, no matter how I try to work things out, so this should help things out immensely.

Bauhn Solar-Powered Power Bank

Bauhn Solar-Powered Power Bank

So to test things, I ran my mobile phone down to 80% charge and then connected the phone to the power bank. It took the better part of an hour to bring the phone back to 100% charge and, as soon as the phone was fully charged, the power-bank turned off – that’s a good thing. During that time, the fourth light on the power-bank was blinking all the time, but when I disconnected the phone and tested the power level on the power bank, all four lights illuminated. I then placed the power-bank in an area where it would get indirect sunlight (far too hot for direct sunlight at time of writing) and the fourth light started blinking, indicating that the power-bank was charging. So I left it there to see how long it would take to bring it back to full charge. However, after seven hours, the light was still blinking, so I decided to put the power-bank on a charger and see how long I’d now need to charge with full power. About three hours later it was fully charged, so don’t rely on the solar panel to do much more than slowly top things up.

Charging a mobile phone

Charging a mobile phone

As for the USB Voltmeter, it’s a pretty nifty device. It doesn’t tell you the final voltage of the device that’s been charged, as that’s not what it’s designed to do, but it will tell you the input voltage (so you know that the charging device/power source is working properly), the current (Amps) that’s being delivered and the total milli-Amp hours (mAh) delivered, which is a good indication of how much a battery was drawn down. That can be really useful information when maintaining batteries. In the photo, you’ll see that the power-pack is only delivering 0.33A and that’s because the phone was more or less fully charged, so the current was now trickling in before it fully shut off.

Update: After mere days over 12 months, the Bauhn power pack went wheels up. Now I haven’t used this power pack all that often, but I have kept it regularly charged to maintain good battery management. But over time I noticed that it was constantly low on charge and when we had a blackout today, I took the power bank out so that a friend staying over could charge their phone. No such luck with the power bank as it was almost out of power.

Once power was back on, I put it on a charger where it sat for most of the day with the lights cycling and when when the lights went out, so it seemed did the power bank. When I plugged in the USB Voltmeter, it registered power for a moment and then blanked out, nor would the power bank charge any device. So at the end of the day, this device was a complete waste of money.