Battery Monitor based on SG

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stephendv
stephendv Solar Expert Posts: 1,571 ✭✭
in Off Grid Solar & Battery Systems #1
Hi all,

I've been working together with Tim (aka Blackswan555) on a battery monitor based on the JSA Photonics digital SG sensor and have the base unit working properly.
Currently supports displaying values on LCD and accessing them over SMS. Ethernet is not working properly, I had it uploading to pachube.com but the whole board would hang after a few minutes - so that's still being worked on.

Full project details here: http://www.casanogaldelasbrujas.com/blog/battery-monitor/
and some more photos: http://www.casanogaldelasbrujas.com/blog/2011/02/20/version-0-1-battery-monitor/

Next features to be added:
- SMS Alerting on low SG
- Monitor SG during EQ and send SMS alert when it stops rising
- Remote generator control over SMS is already in the code but I haven't tested it with relays yet
- Auto gen-start on low SG
- Monitor generator current and switch on second relay for additional optional loads

Project is open source and the code is on the web page above.

Feature suggestions welcome :D
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Comments

  • waynefromnscanada
    waynefromnscanada Solar Expert Posts: 3,009 ✭✭✭✭
    #2
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    Re: Battery Monitor based on SG

    I like the idea. Go for it. Been wondering for some time why such an animal doesn't exist. At least not that I've heard of.
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  • Ralph Day
    Ralph Day Solar Expert Posts: 1,019 ✭✭✭✭
    #3
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    Re: Battery Monitor based on SG

    My beef would be that you can only monitor one cell at a time. I can do that in 15 seconds with my hydrometer, and then a couple of random checks on other cells to confirm battery SOC.

    Now, if it was reliable and wireless then you could dip in each cell, just like a hydrometer, but without the sloshing and splashing. The sloshing and splashing does stir up the electrolyte a teeny bit, at least the top few centimeters of it.

    Ralph
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  • blackswan555
    blackswan555 Solar Expert Posts: 246 ✭✭
    #4
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    Re: Battery Monitor based on SG
    My beef would be that you can only monitor one cell at a time. I can do that in 15 seconds with my hydrometer
    You could use as many sensors as you want, They could update every 200ms, 24/7 We are thinking of 2, one in your "best "cell" on in your "worst", that would enable EQ "alerts" and give better reliability,
    I used it to do an EQ a few weeks back, from previous records, I know which cell is the last to come up on this bank, I put the sensor in that one, Did confirm with traditional hydro a few times, but spent most of the day sat in my truck watching a screen (well surfing net :-) till sg stopped rising, best , easiest, safest EQ I have ever done,
    Now, if it was reliable and wireless then you could dip in each cell, just like a hydrometer

    reliability is a problem at the moment, The sensors do not seem to like air travel, Which needs working on and on board SD card storage, wireless could be added at a later date reasonably easily.
    I have also "had" mine acting as what would be gen control, Using a bat charger, a load and the sensor to switch depending on SG, That did about 30 x 1.200 > 1.270 reliable cycles before prototype No 2 came about :-)

    A work in progress:D

    Have a good one
    Tim
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