Battery Analyzer Design

Interested in having a Battery Analyzer (answer later if you are undecided)

  • Yes, definitely interested

    Votes: 16 59.3%
  • Might be interested

    Votes: 11 40.7%
  • No, wouldn't be interested

    Votes: 0 0.0%

  • Total voters
    27

Alan B

Flashlight Enthusiast
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Nov 19, 2007
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I designed a fairly simple battery tester that might be interesting to make, if there is sufficient interest. Something for testing single cells and providing data along the lines of the West Mountain Radio Computer Battery Analyzer, but much lower in cost, voltage and power capability.

This design is based on a small AVR microprocessor (along the lines of what we are using in the Hotwire Regulators), an FET and a serial interface to the host computer. The software would be open, both on the micro and on the host computer. I envision it handling one cell, up to 4.2V and currents in the up to several amp range.

How much interest in a low cost battery analyzer like this?
 
Depends on price and availability of funds when the device is ready to sell.

Having watched the hotwire regulator development project, I'm looking forward to seeing this one, too. Hope I have funds when they're available.

Thanks,
Steve
 
Price depends on a few variables. How many are built, some of the performance parameters can be adjusted, etc.

We could go with a kit - solder it together yourself..

How cheap does it need to be? Is $50 too much?
 
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i have always concidered the CBA to be pretty reasonably priced, not for what it IS, but for what it does, and how valuable the info has been when shown to us , thanks to the people who have them who put in way more than the $100+ bucks in THIER time to display the results.

hardware and its software too , developed for a long time, connections to the computer, dealing with microsoft alone is worth the $100 :)

anything that does almost the same thing, and that sold for half that, would probably be used by many more people than the CBAs have been used. heck that isnt the price of a charger.

I dont have a CBA, because it doesnt have a charger IN it, from what i understand, its really a CDBA :)

will it work via the USB? will you program in something OTHER than net framework, how many other THINGS will we have to buy if we get the cheap version and have to mod it up to the CBA that is sold, thermal probes, graphing, we need a resistance checker, might as well put that in too :)

i hope you can pull it off even if its $100 and only does what the competition does, and there isnt any stupid patent garbage from someone who didnt even make/sell one.

just a RC wattmeter thing can cost $46 and it was more when it first came out. so there must be markets , but it might have to reach those markets for to be profitable for your time.

to commit to it at a specifc price, we would have to hear all the magic plans , and features that it will have, and how glorious it would be without bugs, then we can ***** about it later , or you could just do what the rest of the expert modders and electrical engeneers have done before.
make one for you, and show it, and see if the :paypal: signs :goodjob:start popping up :takeit:

there are people who would assemble it themselves, and there are people who would buy it who both couldnt assmemble it, wouldnt assemble it, and people like me, who would assemble it backwards :)
where they sell kits of some thing, they have started selling assembled kits of the same thing, for 2X the money, for the lesser skilled.
i assume they make money on both, EVEN if i have the skill to assemble the kits, i prefer the ones pre-assembled when available , because the person putting many together doesnt fumble around so much, there is a reasonable expectation that it worked before i got it (vrses because i built it).
I aint soldering no hairleg chips myself, i can barely do repairs on stuff like that, for me to assemble it it would have to have old school big parts.
 
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I'm trying to keep it fairly simple. The CBA has a lot of capability which adds to the cost, no sense in duplicating all of that in Mark I.

I find it useful to test singe cells, such as AA NiMH, alkaline, lithium, etc. The CBA is really overkill for that.

To keep price low and avoid the USB certification process I think serial is the way to do the interface. Folks already have USB to serial adapters, or they can be readily purchased at commodity prices.

My tendency on the software is to use Python for the computer side, and Gnu C for the AVR side. Platform portable, easy to work with. Other folks can develop other applications for it. Commands would probably be simple ascii serial. Set a current and a terminating voltage, and the output would be about one reading per second with voltage, current, integrated current, etc?

If I do this I will lay out a PC board and have three made. So early testing/development would be up to a group of three. This project has to be fitted into an already busy schedule so it will take a little time, but it is a lot less complicated than the hotwire regulator, for example.

I'm thinking it will be a circuit board with rubber feet, no enclosure. A DB9 for serial, a coaxial jack for a wall wart 9-16V. You can always mount it in an old battery charger and use the nice battery connector (one of them).

How important is a temperature sensor? I generally don't see a need for that on a modest discharge only setup, so might not bother with that.

For current, is a couple of amps sufficient? Some of the special cells will go a lot higher, but is it necessary to go there?

Feedback?
 
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for testing it would be relative to anyones uses for that cell, meaning, i would think they would want to test the same way they use, which means up to ~10A max, probably a 5A min if we're to even test Cs and Ds. there are MANY light items that have only 20-30min runtimes. in AA and li-??

i bet most people could drop it in a box, pelican case, radioshack box, assemble some acrylic from tap, or put it in a nice fitting carboard box that they have lying around . but myself i wouldnt leave it out of a box, because something metal would certannly land in it.

those IR thermal pointers are cheap, but they dont look for you, and write nice graphs or turn on magically at the time you need them for testing CHARGING, , , ,but you aint charging, so i guess for me it wouldnt be so terribly important, now that i think about it.

very good idea to have simple brainless askii going through to software, less problems with interfaceing and diagnosis.

one second intervals would be completely sufficient for any discharge application that i can think of, 10 min discharge giving 600 points, sounds ample

and no i dont have serial any more , after the usb serial "took over" i have avoided the other serial whenever possible.
so usb to serial cable and DRIVER, or fire up the old port again, which is probably easier than dealing with one more conversion thingeee.

i think all the power folks could power it 20 ways , still a finished package makes more people use it too, as in everyone, sometimes Collecting/buying the parts is a longer process than assembly and understanding and use.
many thing discussed in many previous threads, leds, lights, power, etc, no longer exists, good deals on usable items were bought out, hoarded, and ended in general. then trying to make the project again, becomes a very difficult and time consuming task, depending on the missing part.

(just some of my take on it, as usual)
 
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...Commands would probably be simple ascii serial. Set a current and a terminating voltage, and the output would be about one reading per second with voltage, current, integrated current, etc?

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I'm thinking it will be a circuit board with rubber feet, no enclosure. A DB9 for serial, a coaxial jack for a wall wart 9-16V. You can always mount it in an old battery charger and use the nice battery connector (one of them).

How important is a temperature sensor? I generally don't see a need for that on a modest discharge only setup, so might not bother with that.

For current, is a couple of amps sufficient? Some of the special cells will go a lot higher, but is it necessary to go there?

Feedback?
Capacity is an over-rated but rarely seen toy...if you convert the "sink" into a source, you can also use the analyzer to double as a charger. It would be interesting to keep a history of the measurements in an array so that one could play with the termination condition. This seems to be a bigger issue today with older batteries.

On the analyzer front, some manufacturers have measured the terminating voltage under load. Any idea if the load would be pulsed or DC ?

I might be interested in a board.

PeAK
 
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Price depends on a few variables. How many are built, some of the performance parameters can be adjusted, etc.

We could go with a kit - solder it together yourself..

How cheap does it need to be? Is $50 too much?
A kit is no problem at all. I have a few soldering irons in the garage. They feel rather neglected, but a kit could fix that.

$50 for a working design with all the parts seems like I might be able to do that. I know the quality would be there (still dreaming about the last photo I saw of your hotwire regulator in its sled). Now to see if I can collect the spare change...

Thanks,
Steve
 

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