D3 Ammeter Options?

[Mully]

Greets all.... was curious to know if anyone out there has installed an ammeter into their D3 (or D4)? Given the load these beasts draw & the fact that they need to be reliable in often remote locations, I figure someone here may have looked at a few solutions/options?

Obviously a conventional moving coil meter could be wired in like any 'normal' vehicle but is there a simpler electronic option... connecting to the Disco OBD setup for example? Assuming a Scangauge etc would do this function but I'm hunting for a more economical single purpose option if there is one out there.

Thanks for any suggestions.
Cheers.

PS: forum searches haven't revealed anything.

[bbyer]

The link below is to the Traxide people, (drivesafe on the forum), who make a pretty good dual battery interface for the 3 and 4.

Drivesafe at least understands which direction power is moving from the main starting battery and where it is coming from or going to, and more importantly, why and how. That brings up another question - is that what you were thinking of monitoring?

I think perhaps you were wondering what current the alternator is putting out at any given time or were you wondering what current the vehicle systems were drawing or - well it keeps on going, particularly with multiple batteries.

As such, the solution to what you may be asking is not easy to answer any longer. When a vehicle electrical system consisted of a generator, a battery, and a load, (the vehicle), it was not too hard to insert something somewhere to at least tell you what the battery was doing, charging or discharging, and that would mean something. Now it is not so easy.

My own view is that if you want to monitor alternator output, taking a measure of field voltage used to give a pretty good indication of load, (higher field volts, the harder the alternator was working). With these new alternators, I do not even know it they have what used to be called field voltage. I have attached the battery / alternator wiring diagram for an LR3 and the only wire identifier word I understand is B+ and maybe Batt Sense coming off a 5 amp fuse that I presume provides 12VDC power to what I used to call the Field, but somehow I think it is called something else now.

I even see a couple of locations where I "suppose" one could insert an old fashioned shunt and monitor amps in or out of the battery or alternatively, amps out of the alternator, but somehow the term "old fashioned" bothers me. I figure some Can Bus monitoring system would probably pick up on the shunt and throw a fit - well drop the 3 to the stops as that seems to be the first reaction to any concern.

Anyway, it may be simple and I may be making a too big deal of it, but the word "obvious" and my word "suppose" does bother me. The question is an interesting one however.

D3 (http://www.traxide.com.au/D3_kits.html)

[101RRS]

I don't believe Scangauge gives a reading of amps - does voltage though. Scan gauge is cheap at $160 especially as no modifications are required to connect and mount it.

Surely the voltage readout from a scangauge or even a basic voltmeter combined with the charge light on the dash is all you would need.

Garry

[bbyer]

I don't believe ScanGauge gives a reading of amps - does voltage though. Scan gauge is cheap at $160 especially as no modifications are required to connect and mount it.

Surely the voltage readout from a ScanGauge or even a basic voltmeter combined with the charge light on the dash is all you would need. Garry I have the ScanGauge II installed and yes, it does give voltage, (no amp readings), but from just where the voltage reading is taken, I am not certain. The ScanGauge is connected to the OBD port, but from where the OBD sources its voltage, I do not know.

My guess is that it gives alternator output voltage when the engine is running. The voltage numbers seem to suggest that. Readings vary from a high of 15.0 to about 12.4 volts, but mostly run about 13.9 volts.

These numbers seem to me like alternator output voltage rather than battery or buss voltage.

[Blknight.aus]

a simple dedicated clamp on amps meter can be obtained from Jaycar in kit form.

as it reads in both directions clamp it to the earth lead of the battery and it'll tell you how much is going out or in at any given time.

[Mully]

I have attached the battery / alternator wiring diagram for an LR3 and the only wire identifier word I understand is B+ and maybe Batt Sense coming off a 5 amp fuse that I presume provides 12VDC power to what I used to call the Field, but somehow I think it is called something else now.

D3 (http://www.traxide.com.au/D3_kits.html)

Thanks a bunch for the PDF... very helpful! I did look at Traxide site actually while on the prowl for options thinking their dual kit may provide a dual excuse for purchasing one. :)

I'll check out the Scangauge option as I didn't realize they were that price... interesting.

The Jaycar kits I'll have a look at too as we have trade accounts with them... you never know.

The voltage output is I think not a 'real' help as these type of alternators I believe have constant output at all revolutions so I'd expect it only fluctuate a little while actual current draw is the real number I'd like to see and which direction it's going in... be useful to see how quick the battery comes back up after a start etc for one thing.

I've had an alternator die now and the battery has been brought back to life a couple of times now (actually has an RAA 600CCA in it... huh?) and I can see a real need to be on top of the electrics of the D3 especially when off the black stuff.

Interesting comments... thanks.

[drivesafe]

a simple dedicated clamp on amps meter can be obtained from Jaycar in kit form.

Hi Dave, do you have a link to the kit at Jaycar. I’ve had a look through their cattle-dog and not found it.

I’ve been looking for high current non intrusive current monitors for years and never found anything that didn’t need installing in-line to get a reading.

I use a clamp meter but have you ever tried taking a current measurement with the bonnet up, hanging over the grill doing a hundred kph down the freeway. Hell does it blow a breeze up the kilt, and the wife finds it very difficult holding on with only one hand.

Seriously, I have come across a few AC clamps that can be fixed over a cable and a normal multi meter can be used remotely to get measurements but I have not come across any decent DC remote clamps.

The D4’s 140 amp alt/gen is bad enough but the D4’s 180 alt/gen makes it next to impossible to get an idea of what is going on.

[ADMIRAL]

Try ABR Sidewinder. They have an aircraft setup available if your budget will stretch to it. ( $300.00 plus ) Looks the goods. I cannot comment as to how good, bad or otherwise.

If you are looking for a simple setup, Wurth, SnapOn and I believe several other tool suppliers, make a plug in ampmeter for a single fuse draw. ( remove the fuse, plug in the tool ) I have the Wurth tool. Not really suitable for remote mounting though.

[bee utey]

Ammeter shunts available:

150 Amp 50mV Ammeter Shunt | eBay (http://www.ebay.com.au/itm/150-Amp-50mV-Ammeter-Shunt-/200608681036?pt=AU_Boat_Parts_Accessories&hash=item2eb5358c4c)

Suggested to fit into the battery earth cable.

[drivesafe]

Sorry ADMIRAL but with Sidewider’s track record of supplying garbage and not backing their warranty, not a good recommendation.

Hi bee utey, there are plenty of shunt type set ups but the problem is where would you put it in the D4 with out risking problems.

The D4 diagnoses it’s battery by analysing the neg cable coming from the battery and as a shunt needs to be in the neg cable it would not be advisable to do this on a D4.

To get accurate current diagnostics on a D3 or D4, you need high side monitoring ( positive ( + ) monitoring ) and it really needs to be a clamp type not and inline type plus, you would need to monitor in a number of different locations to evaluate what current was going where.

BTW there is also an advantage to high side monitoring on most vehicles because it is usually much easier to fine a positive cable than it is the separate a cable from a bonded earth to the chassis or bodywork.

[Blknight.aus]

dont go using a shunt to do the measurement, I have a nasty feeling that the resistance of the shunt will throw the management system on the new advanced vehicles.

The kit that I was referring to is now replaced with this one. AC/DC Current Clamp Meter Kit for DMMs - Jaycar Electronics (http://jaycar.com.au/productView.asp?ID=KC5368&keywords=amp+meter&form=KEYWORD) which is out of stock and will also require the addition of a simple volts meter kit to make use of it.

heres the altronics one.

Altronics - Your One Stop Audio Visual & Electronics Supplier (http://www.altronics.com.au/index.asp?area=item&id=K2582)

and heres the original silicone chip one.

http://www.siliconchip.com.au/cms/A_30551/article.html

[Mully]

The ABR stuff looks pretty much what I had in mind & the aircraft style model looks great. Prolly need to look further in to a clamp option... never been a fan of running huge cables back behind the dash.

Cheers.

[Mully]

Hey thanks Dave... will check these out now.

[drivesafe]

Thanks and thanks Dave, I remember the original project in Silicon Chip. Unfortunately for what I want to measure, the d4’s alternator to cranking battery cable currents, it needs a maximum in access of 180 amps.

Hi Mully, if you go with the kits, wrap everything in electrical type and/or heat shrink, that includes the toroid cores, it won’t change the accuracy of the Hall Effect but it will prevent possible shorts when you try accessing some of the cables around a vehicle.

BTW if you want to use the info gained from the current measurements to control different devices and/or events, while you can use shunts to get accurate current measurements, but because they are installed in the negative circuit, they are not reliable because if you get a short, they can not see it.

Whereas, high side current monitoring is perfect for sensing shorts.

[bbyer]

The ABR stuff looks pretty much what I had in mind & the aircraft style model looks great. Prolly need to look further in to a clamp option... never been a fan of running huge cables back behind the dash.Cheers.

If the amp meter you are referring to is per the link below, it is probably good for an early Defender but as for a current D3/4, I am not so certain. The use of a shunt really bothers me.

There are two kinds of airplanes, light and heavy. Light is generally piston gasoline; heavy, the jet sort. The electrical systems on most light aircraft are early Edison, so simple even I can understand them and the referenced instrument would work well. It is not the sort of thing I would be installing on my Lear however. Per the other link below, MGL makes instruments for homebuilt aircraft, not always the most advanced, at least electrically.

Also my view is that the D3 electrical system was designed by some laid off AirBus types who were picked up by BMW. The whole wiring system of the D3 just looks more heavy aircraft than it does early Series.

MGL Bat 1 (http://www.sidewinder.com.au/page164aa.html)

Infinity Singles (http://www.mglavionics.com/html/infinity_singles.html)

[Mully]

Thanks guys.... the Silicon Chip would be great except it is only 80A as mentioned. The other options using a remote volt meter are a bit ordinary and not what I'm after. The MGL units look exactly what I'd like to achieve and if I can sort a decent clamp circuit, I'll put something like that together from scratch if need be.

Challenge number two may be finding a place to locate said gauge!

Drivesafe thanks for your input and I'd love to see you come up with a kit as a solution. I'm quite surprised that after 6 years or so that there isn't a commercial option for the D3/4 on the market, it's such an important piece of information and I shudder at the thought of relying on the alternator in dash 'globe' to tell me I may not get home without a jump start. :)

The search continues and thanks again one and all.

[Ashes]

Would something like this be suitable for monitoring draw on a 2nd battery (isolated from the main battery by a Traxide SC40)?


http://www.ebay.com.au/sch/i.html?_from=R40&_npmv=3&_trksid=m570&_nkw=DC+50A+Blue+LED+Digital+Ammeter+AMP+Meter+%2B +Shunt+75mV

I'm thinking placing this after my 2nd battery and before my accessories fuse box (installed under the drivers seat). This should give me an indicator of current draw when running my fridge, lights and other bits and pieces from the fuse box? Would this also measure the amount of charge going into the battery when driving or would I need to place the shunt between the SC40 and battery to see charging rate?

[gps-au]

Would something like this be suitable for monitoring draw on a 2nd battery (isolated from the main battery by a Traxide SC40)?


DC 50A Blue LED Digital Ammeter AMP Meter Shunt 75mV | eBay (http://www.ebay.com.au/sch/i.html?_from=R40&_npmv=3&_trksid=m570&_nkw=DC+50A+Blue+LED+Digital+Ammeter+AMP+Meter+%2B +Shunt+75mV)

I'm thinking placing this after my 2nd battery and before my accessories fuse box (installed under the drivers seat). This should give me an indicator of current draw when running my fridge, lights and other bits and pieces from the fuse box? Would this also measure the amount of charge going into the battery when driving or would I need to place the shunt between the SC40 and battery to see charging rate?

If you just want to measure in/out on the one battery, put it in the battery negative lead to the chassis.

If you want to measure the load for one item, you should set up a test lead. Personally I use "rigrunner" type boxes (google it and west mountain radio) and all accessories (non-factory) are run using "powerpole" connectors (normally 30A do nicely) to the rigrunners.

I actually use "rigrunner" as power distribution boards in my trailer as well, so everything is standardised.

[drivesafe]

Hi Ashes, if you want to get high current amp readings, the simplest way it to fit two of the shunts in parallel and connect to one of them.

Just remember that that the reading you get has to be doubled.

The other way for getting both volt and amp reading is to something like a Doc Watson meter ( se the link below ) fitted with Anderson Powerpoles as gps-au suggested.

Watts Up and Doc Wattson power meters. (http://www.braingarage.com/Dons/Travels/articles/power/wattsup.html)

I have made up loads of different cable set ups using the Anderson 15, 30 and 45 amp Powerpoles so I can plug what ever I need to into a set up for testing.

The Anderson 15, 30 and 45 amp Powerpoles all use the same size housing so they are interchangable and all plug together.

Although these meters cam measure up to 100 amps, because the cables connected to these meters is so thin, I rarely use them for loads much greater than 30 to 40 amps max.

https://www.aulro.com/afvb/images/imported/2012/05/337.jpg

https://www.aulro.com/afvb/images/imported/2013/02/681.jpg

https://www.aulro.com/afvb/images/imported/2013/02/680.jpg

[Ashes]

Thanks guys, at this time I'm just interested to see the total draw so I can estimate battery life based on what I'm running when camping and more carefully use the "expensive" drawing items. I can run each device independently so I can cycle though each of the devices to see what they are doing.

So to get this clear in my head and based on the following guide which is likely to be pretty standard

http://jaycar.com.au/products_uploaded/QP5588%20User%20Manua.pdf (http://jaycar.com.au/products_uploaded/QP5588%20User%20Manua.pdf)

- place the shunt in the negative/earth cable between the 2nd battery neg terminal and the chassis ground point, connecting it in serial with the 2 large terminals on the shunt
- the digital ammeter has 4 inputs ( +/- power and +/- signal input)
-I can take +/- power from my accessory fuse box or a 9v battery (might put a switch on it so it's not on all the time or use a swith I already have on a digital voltmeter)
- the negative signal input is one of the small screws on the shunt and the positive the other.

With this setup and using a 9v battery for power the only cable I would need to run would be 2 relatively thin wires from the shunt back to the display.

Will the digital display show a "-" when devices are using power and a "+ or nothing" when the aux battery is charging?

Am I missing anything in regards to this?