Car Battery Voltage Meter.

[SpitFire6]

Hi,
I would never waste a hole for a 52mm voltmeter. Instantaneous display of the battery voltage is intuitive, especially if the reading is digital.
Analog would look nice if it was scaled better than the norm, something like 13.6 - 14.6 over 270 degrees?

I have used a USB cigar plug-in adaptor with a voltage digital display of +/-100 mV.
Display across the usable range is accurate and it is effectively connected to battery terminals as the current draw is <10mA.

I have found a better device to use my phone wirelessly to display the actual battery voltage. The ability to export historical data is useful. SOC readings are as good as can be with voltage vs SOC measurements.
 

Battery module costs around £10,

 

BRB when I find a picture.

 

Edited December 25, 2023 by SpitFire6
Price now £17!

[Colin Lindsay]

For me, it's the period feel of the whole thing. Digital is effective, accurate and completely the wrong era. It's like the anachronisms that movie buffs spot in films. I fitted a battery condition gauge, needle sits at about 14 until I turn the lights on and it drops to 11, and it just takes me back to the earlier days of motoring. I've a few modern meters and scanners in the garage (just got a Creator 410 to play with) but they're plug-and-test out of sight, and overkill for the Heralds. It just seems guiltily efficient to use anything modern!

[johny]

11 hours ago, SpitFire6 said:

Cool bit of kit but Im going to fit one of these in the side of my Vitesse glovebox...

[dougbgt6]

I had an ammeter, but the wiring got very HOT, so replaced it with a Smiths Volt meter, very nice, but by the time you've noticed the voltage dropping, it's too late! I have in my upgrade drawer a digital ammeter, the battery cable goes through a ferrite ring and the current sensed (I'm not sure how!) It has an LCD display, I think it's going to go in the ashtray?

Doug

Edited December 26, 2023 by dougbgt6

[SpitFire6]

Historical & trends are useful.

[johny]

Hours of fun😁

[Colin Lindsay]

interesting and fascinating, but don't you start to worry when there are blips or momentary surges? 

[Wagger]

Don't spend too much time watching displays. You could run into somebody or something. Check that the 'Charge' light in the speedo is working and let that tell uou if there is a problem.

 

[johny]

Ah but if you run an old regulator box I think... Im right in saying the ignition light can be out because the dynamo output is good but that doesnt mean its getting to the battery☹️

[Pete Lewis]

I have some very old indestructible lucas testers one for battery /starter/alternator

and being just 3 led voltage lamps  for what ever you are testing 

and are just 3 voltages   so you get good bad  and useless

no fafing about for a quick clue , just clip on the battery and follow the test 

bit like these but mine are simples  from the 70s 

[SpitFire6]

Hi,

If you need diagnostics from the battery you can download 30 days of data. data points are every two minutes.

Cheers,

Iain.

 

ACU77L _Dec 2023_Report (5).xls

[Colin Lindsay]

2 hours ago, SpitFire6 said:

Hi,

If you need diagnostics from the battery you can download 30 days of data. data points are every two minutes.

Cheers,

Iain.

 

I'm interested in what that tells you, exactly. Over time, yes, you can see the battery performance fade, so maybe the battery is on the way out, or not charging, but isn't it just another source of worry over figures that you analyse in unnecessary depth? (Good fun tho so I can understand it)

[SpitFire6]

1 hour ago, Colin Lindsay said:

I'm interested in what that tells you, exactly. Over time, yes, you can see the battery performance fade, so maybe the battery is on the way out, or not charging, but isn't it just another source of worry over figures that you analyse in unnecessary depth? (Good fun tho so I can understand it)

I'm sure I will get bored with it. I am using it at the moment as trying to increase the charging voltage a knats.
The voltage trends are interesting. Shame the wireless range is only a few meters on this model. The cranking test has shown low voltage readings which is odd.

Cheers,

Iain.
 

[Morgana]

I wouldn't worry about it if I were you. Lead acid batteries have a finite life. As long as there's a charge current to replace that drawn when starting, and it retains that, all is well. It's impossible to tell the state of a battery during charging using a voltmeter, as any voltage reading is only indicative of anything once the cell has settled with the charging current removed. I guess if you were particularly keen to have the most long-lasting charge possibility then some complex circuitry to make a 'smart' charger would be best, rather than the simple increased resistance to inward current flow the cars rely on. Good information here.

Personally, the ignition light and a check with a meter and hygrometer if the starter's turning slowly are all I think are necessary with these cars. The battery will need replacing whatever you do every few years, so I wouldn't add to that with worrying about regular data points.

[Wagger]

I do have two auxilliary sockets with built in LED's which echo PeteL's kit, Good, mediocre and useless. I am not colour blind so can use these as they are red, amber and green,

In the days before I fitted an alternator, I used my bench voltmeter and current clamp to check charge monthly.

 

[PeteH]

One of the issues with "Sealed" batteries is the fact one can no longer test individual cells with a Hydrometer. Something I think is a Retrograde step. There are, clearly, situations where having "open" cells would be dangerous, but under the open Bonnet of an old(er) car?. Testing with a Hydrometer was how I discovered the just one battery in a Bank of 6, was defective and the "cause" of lost capacity. With 6 batteries and 300Watts of solar panels I could "Off Grid" for nearly a full week.

I suspect "plum`s" battery is nearing the end of life, It takes a charge overnight, and by the following day is down to 12v or less just standing. Not having the "Ghost drains" of a more modern vehicle I think a new Battery is on the cards soon.

Pete

Edited December 28, 2023 by PeteH

[JohnD]

It used be that the terminals of each battery cell were exposed on top.  Even easier to check the cells with a volt meter!

But thats progress for you.

John

[Wagger]

1 hour ago, JohnD said:

It used be that the terminals of each battery cell were exposed on top.  Even easier to check the cells with a volt meter!

But thats progress for you.

John

Yes, mine had no cover and I stood a can of oil on it when topping up, not paying attention to where I put it. I heard this boiling sound when reading the dipstick. That's where the term 'Dipstick' came from then.

[Colin Lindsay]

...which is why cars these days come with a warning: "Do not drink the contents of the battery". Sad, but true.

 

[PeteH]

7 minutes ago, Colin Lindsay said:

...which is why cars these days come with a warning: "Do not drink the contents of the battery". Sad, but true.

 

Not exactly a new phenomenon either, If we flame cut steel, it often got left on the floor. so we chalked "Hot" or "OTAZEL" on it as a precaution, Always some Divi would burn his hand trying to see just "how" hot!. How many times do youe see "wet paint" signs, and what happens, someone WILL touch to see!

Farmer, put a sign up "Bull In Field" and the "ramblers" still walk through!. You can`t Legislate for Loonies.

[JohnD]

Must be getting slow, took me ages to work out OTAZEL!

 

[SpitFire6]

Hi,
The ability to measure individual cells of a pack/battery is informative and necessary for some cell technologies. The life of the pack can be maximised.
Not possible to change a cell with a car battery so why bother/worry that a weak cell is holding the other 5 back?

On a fully charged battery the resting voltage will point to a problem if compared with the internal resistance. The internal resistance is a very useful metric. Easy to calculate & cheap to measure.
Cheers,

Iain. 

[ahebron]

When I was doing my time back in the early 1980s we had one chap whose job was looking after the battery packs in the substations. There were lead acid individual cells (2 volts?) consisting of glass battery housings in individual wooden boxes supplying 110 volts DC to power the  control circuits in the zone substations. I recall many a day working in these buildings standing on the top of the switch truck housings and getting a tingle across my legs as I was leaning into the exposed connectors of the 110 volt DC. It did seem a very old fashioned system back then but I suppose if it worked then why change. 

[PeteH]

3 hours ago, ahebron said:

When I was doing my time back in the early 1980s we had one chap whose job was looking after the battery packs in the substations. There were lead acid individual cells (2 volts?) consisting of glass battery housings in individual wooden boxes supplying 110 volts DC to power the  control circuits in the zone substations. I recall many a day working in these buildings standing on the top of the switch truck housings and getting a tingle across my legs as I was leaning into the exposed connectors of the 110 volt DC. It did seem a very old fashioned system back then but I suppose if it worked then why change. 

I think the post office now, BT, only got rid of that type of system for power backup in exchanges, sometime in the 80s or even later. When my youngest went to work for them. The Yeovil exchange, he sad, still used those old 2v glass cells. 
 

Pete

[Pete Lewis]

the old glass 2v cells  we had at school in the 50/60s  we decided to join a few up and weld/burn names in some tin labels we acquired then  after some charging and rapid discharge was a spark ignited  explosion , only the metal carry strap saved me from injury ,the two screw terminals are probably still stuck in the ceiling panels. and the acid disolved a big white patch in the red tile coloured floor 

well we all learn a bit by experimenting  Hmmmm 

Pete