Small stand-alone amp meter?
- Thread starter Bbasso
- Start date
M35A2
Tinkerer
Add a shunt resistor if you need it to handle higher currents. That's what is inside an ammeter for it to handle higher currents. They are not running all that current through the meter!
pugslyyy
Expedition Vehicle Engineer Guy
dwh
Tail-End Charlie
Shunts are inline (serial) in either the hot or negative line. There is no polarity.
pugslyyy
Expedition Vehicle Engineer Guy
Something to track all of that intelligently gets more complicated and expensive pretty quick. This is what I have - http://www.blueskyenergyinc.com/products/details/ipn_proremote
It would be much cheaper/simpler to track what power you are using after you have stopped for the night, etc with something like this - http://www.ebay.com/itm/DC-100A-LCD...ter-Ammeter-Voltmeter-Multimeter/181814298183
Current shunts themselves are very simple - it is just a very precise but very low resistance resistor. You measure the voltage drop across it, and infer the current. They work both ways, if your shunt shows positive when you are drawing power and negative when you are charging you just need to swap the two wires between the shunt and the meter.
(side note, I am describing DC current sensing here. AC current sensing is done differently (non-contact / electrically isolated)
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DiploStrat
Expedition Leader
The TriMetric is a very commonly used hour counter. Some here have argued in favor of various Victron products.
The simplest to install is the SmartGauge, as it does not use a shunt, but it is very controversial: http://www.smartgauge.co.uk/smartgauge.html
(If you buy, order from Defender Yacht who sell the Balmar branded, US version - a bit cheaper than a one of a kind import from UK.)
I have a TriMetric (yes, I read Handy Bob) but use the monitor built into my Blue Sky controller more.
It is very, very difficult to know a true state of charge, but I would not be without some form of meter; a voltmeter is next to useless for this purpose as camper batteries are almost always either charging or discharging - you never see a real resting voltage.
The simplest to install is the SmartGauge, as it does not use a shunt, but it is very controversial: http://www.smartgauge.co.uk/smartgauge.html
(If you buy, order from Defender Yacht who sell the Balmar branded, US version - a bit cheaper than a one of a kind import from UK.)
I have a TriMetric (yes, I read Handy Bob) but use the monitor built into my Blue Sky controller more.
It is very, very difficult to know a true state of charge, but I would not be without some form of meter; a voltmeter is next to useless for this purpose as camper batteries are almost always either charging or discharging - you never see a real resting voltage.
plh
Explorer
This will be the difficult part
Tennmogger
Explorer
Take a look at the Watts Up meter (search "watsup meter"). It will show you the battery voltage, realtime amperage, peak V, peakA, and most importantly Ampere hours.
Available with several means of attachment. I have a couple of them and prefer the one with wires, to which I added Powerpole connectors for all my 12v stuff..
Copied this off one site:
Specifications:
Voltage 0-60 V, resolution 0.01 V.
Current 0-100 A peak, 50 A continuous, resolution 0.01 A
Charge 0-65 Ah, resolution 0.001 Ah.
Power 0-6500 W, resolution 0.1 W.
Energy 0-6500 Wh, resolution 0.1 Wh.
These little multi-function meters are very handy to know how much energy has been taken out of a battery, or, how much has been put back in.
Available with several means of attachment. I have a couple of them and prefer the one with wires, to which I added Powerpole connectors for all my 12v stuff..
Copied this off one site:
Specifications:
Voltage 0-60 V, resolution 0.01 V.
Current 0-100 A peak, 50 A continuous, resolution 0.01 A
Charge 0-65 Ah, resolution 0.001 Ah.
Power 0-6500 W, resolution 0.1 W.
Energy 0-6500 Wh, resolution 0.1 Wh.
These little multi-function meters are very handy to know how much energy has been taken out of a battery, or, how much has been put back in.
jonyjoe101
Adventurer
for the solar side just get a 90 volt 30 amp combo meter on ebay, there about 20 dollars. it doesnt require a shunt just connect it between your solar panel and battery. Its got a very large led I can read in daylight and leave it connected 24/7 uses very little power, I like looking it at night to see what the voltage on the battery is, in the daytime it tells you how much amps are going into your battery. So far had it running nonstop for 2 years and seems to be very reliable. Highly recommend you get an LED meter, LCD is impossible to see in daylight and you need to be up close to even read it. LCD might use less power but on lead acid batteries power wont be much concern for these low drain LED meters.
Here is a picture of mine installed in a case I made. This the old version of the combo meter, the new version has more features. But happy with the one I got.
I also have a dc wattmeter to measure watts/amps use. Depending how you connect them you can measure how much amps go into battery or how much amps were taken out of the battery. I rarely use them but when I want to see how much power something uses they come in handy. These are about 15 dollars, they do what the combo meter does but LCD is hard to see.
Here is a picture of mine installed in a case I made. This the old version of the combo meter, the new version has more features. But happy with the one I got.
I also have a dc wattmeter to measure watts/amps use. Depending how you connect them you can measure how much amps go into battery or how much amps were taken out of the battery. I rarely use them but when I want to see how much power something uses they come in handy. These are about 15 dollars, they do what the combo meter does but LCD is hard to see.
Bbasso
Expedition goofball
Looks like this is a bit too complicated for me 
My solar charge controller shows amps when charging and volts all the time (switch).
Then I have a cheapo digi volt guage from amazon but that thing never diaplays the same readings as the SCC...
Maybe it's time to upgrade the SCC? Is there one that can display more info and possibly charge a little better then the Sunforce 30 Amp Digital Charge Controller I've had for a while?
My solar charge controller shows amps when charging and volts all the time (switch).
Then I have a cheapo digi volt guage from amazon but that thing never diaplays the same readings as the SCC...
Maybe it's time to upgrade the SCC? Is there one that can display more info and possibly charge a little better then the Sunforce 30 Amp Digital Charge Controller I've had for a while?
DiploStrat
Expedition Leader
Full disclosure: I do not have a SmartGauge; I use a pair of hour counters, the TriMetric and the hour counter in the Blue Sky solar controller.
The SmartGauge's claim to fame is that it is easy to install and, once programmed correctly, will give you a decent state of charge reading. Does it work? Handy Bob swears that it cannot work but Chris Gibson, the gentleman who developed it, started out programming hour counters and developed the SmartGauge because of his dissatisfaction with hour counters.
You money, your choice. ;-)
The SmartGauge's claim to fame is that it is easy to install and, once programmed correctly, will give you a decent state of charge reading. Does it work? Handy Bob swears that it cannot work but Chris Gibson, the gentleman who developed it, started out programming hour counters and developed the SmartGauge because of his dissatisfaction with hour counters.
You money, your choice. ;-)