Voltage regulator - irregular output

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Brownowl
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Voltage regulator - irregular output

Post by Brownowl »

Hi folks,

A quick question...

My '59 traveller has let me down a couple of times lately with a flat battery. It only takes about 20 minutes to get enough into it to start the car, which made me suspicious. After fully charging, I tested the voltage going to the battery with the (1098 with dynamo) engine runni at a fast tickover. It was all over the place, broadly anywhere between 10 and 19 volts, but switching so fast I suspect my digital multimeter was struggling to keep up.

Hence my suspicions it's the regulator.

How best to test, and how to fix please - short of shelling out £20+ on a replacement.

Thanks, Laurie.
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geoberni
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Re: Voltage regulator - irregular output

Post by geoberni »

Hi Laurie
There is a problem with using modern digital equipment on older electromechanical systems, Digital Displays don't react like a conventional Needle meter.
But yes, if you're reading 10-19 v it's got a problem.

Before replacing it, I'd check it's set up properly. Chances are it isn't.
There's a good set of short videos on youtube made by Moss covering how to do it.
Part 1 is here, the others follow on.
https://www.youtube.com/watch?v=SxJNCigb0uA
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oliver90owner
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Re: Voltage regulator - irregular output

Post by oliver90owner »

If it was 10V, the battery would not be charging! The voltage regulator has contact points which open and close. That is likely why you were seeing those results. You need an average reading, as geoberni suggests.

Fitting an alternator removes problems like this, enables a good charge rate at just above idle and will charge the battery to approx 14.4V with relative ease.

Get the old system wrong and the battery life will be adversely affected. Too low voltage will mean the battery may start to sulphate and too high will mean the electrolyte may be electrolysed. If the battery is a modern sealed item, cells are over-pressured with the products of electrolysis - Hydrogen and oxygen) and they may escape through the regulator valve. Replenishment of electrolyte on VRLA batteries is not possible, so the battery life will suffer.

Best to use a flooded lead acid battery, with removable caps (for replenishment with distilled water as necessary), for a dynamo system.
Brownowl
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Re: Voltage regulator - irregular output

Post by Brownowl »

Thanks for the replies.

The voltage is all over the place, too fast and too big a range to even imagine an average. I do have a voltmeter with a dial, so I'll try that.
An alternator conversion on on my to-do list, and will probably happen next spring. In the meantime I'd just like to keep the old girl running, and I'm concerned about it now I see what's happening.

Ok, I've stuck a dial meter on it, and it reads a steady 13v. Great, many thanks for the tip, that's another lesson learnt! Every day is a school day, even at my age...

My mind is at rest over this, and I'll just keep an eye on the battery if I do short journeys,

Cheers, Laurie.

PS. Yes, it's a sealed battery.
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geoberni
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Re: Voltage regulator - irregular output

Post by geoberni »

I'd still recommend taking a look at the internals, to see if the contact gaps are correct.
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Brownowl
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Re: Voltage regulator - irregular output

Post by Brownowl »

Yes, wise advice - I will.

Thanks again.
JOWETTJAVELIN
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Re: Voltage regulator - irregular output

Post by JOWETTJAVELIN »

There is a solid state combined regulator and cut-out available which fits inside the original control box, without altering the vehicle wiring. This is a much better proposition than an alternator.
oliver90owner
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Re: Voltage regulator - irregular output

Post by oliver90owner »

JOWETTJAVELIN wrote: Thu Nov 11, 2021 8:04 pm There is a solid state combined regulator and cut-out available which fits inside the original control box, without altering the vehicle wiring. This is a much better proposition than an alternator.
Which? The regulator or the dynamo - you seem to be comparing apples and oranges. Virtually all modern automotive alternators come with an integral solid state regulator.

If you are suggesting a dynamo system is a better proposition than an alternator, I would suggest you ponder why nearly every vehicle from about the 1970 (and all, now) fit alternators, not dynamos as a means of electrical generation.

Fine if the owner wants to keep his vehicle looking ‘as original’ with the dynamo - a solid state regulator will be far better than the 80(?) year old design, but an alternator will actually easily keep up with both power usage and battery charging whereas the dynamos will always struggle when power usage is at a maximum.

These solid state conversions have been around for years. What is the cost of one to fit inside the original box?

Of course, conversion to a modern alternator will be for 12 volts and negative earth, and reqire a different fan belt.
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Re: Voltage regulator - irregular output

Post by JOWETTJAVELIN »

Eh? I don't know if you are aware that the vast majority of Morris Minors came equipped with a dynamo and RB106 as standard, with wiring to suit. Are you aware what a standard Lucas dynamo as fitted to the Minor is capable of outputting, in volts and amps? I very much doubt it.

A solid state regulator/cut-out conversion, quite aside from fitting neatly inside the RB106 unit, does not require any alterations whatsoever to the vehicle wiring, fan belt or dynamo mountings.
If you are suggesting a dynamo system is a better proposition than an alternator, I would suggest you ponder why nearly every vehicle from about the 1970 (and all, now) fit alternators, not dynamos as a means of electrical generation.
I'm doing a lot of pondering.... pondering what dates you reckon the Minor was in production from until, and what sort of electrical demands you think they make on the battery.

Then again, some people spend more time in their armchairs than driving their old cars, so it wouldn't really matter to them.
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Re: Voltage regulator - irregular output

Post by MCYorks »

Brownowl wrote: Mon Nov 08, 2021 11:21 am My '59 traveller has let me down a couple of times lately with a flat battery. It only takes about 20 minutes to get enough into it to start the car, which made me suspicious. After fully charging, I tested the voltage going to the battery with the (1098 with dynamo) engine runni at a fast tickover. It was all over the place, broadly anywhere between 10 and 19 volts, but switching so fast I suspect my digital multimeter was struggling to keep up.

Hence my suspicions it's the regulator.

How best to test, and how to fix please - short of shelling out £20+ on a replacement.

Thanks, Laurie.
Hi Laurie,

If you haven't already done so, check all the connections on the regulator and dynamo are in good condition, especially the 'E' earth terminal. No amount of adjusting the regulator will solve the problem if any of the connections are poor. The original Lucas service manuals are available online, if you want comprehensive details on regulator adjustment and setup. As people have already said, it needs to be done correctly or there is a risk of damaging the battery or dynamo.

I find the Minor's RB106 regulator is a bit of a compromise really. It tends to overcharge when the load is low and undercharge with higher loads. Maybe the Lucas engineers expected daytime driving to compensate for the night time losses :lol:

If you're driving at night in stop start or slow moving traffic, even if the dynamo is 100% it will usually struggle to fully recharge the battery. With the sidelamps, headlamps, wipers and heater fan going, there's not much current left for the battery :wink:
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Re: Voltage regulator - irregular output

Post by Brownowl »

Thanks one and all for your advice. Gratefully received.

Cheers, Laurie.
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Re: Voltage regulator - irregular output

Post by myoldjalopy »

Similar problem recently - starter struggling to turn engine over but a good 12.6v showing on battery, 13.1 showing after a good run. Once started, easy to start again for rest of the day. But after a day or two, sluggish starter motor again. Took to to be checked and battery duff........well, it was nine years old.
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geoberni
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Re: Voltage regulator - irregular output

Post by geoberni »

myoldjalopy wrote: Fri Nov 19, 2021 10:42 am But after a day or two, sluggish starter motor again...
A very good point, I just reread the OP and there is no mention of Battery age. I hadn't noticed that before.

My Basil had a similar issue to you, although it was more like a couple of weeks between starts, but more noticeable in colder weather. Battery had a good 'Terminal Voltage' but had lost it's 'Cranking Amperage' capacity.

Same thing with my Modern Diesel a couple of years ago.
It let me down after I had done a few 'Stop & Starts' around the village before heading elsewhere...
It no longer had enough capacity to handle multiple restarts, but then it was around 9 years old at the time. :roll:
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KeithL
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Re: Voltage regulator - irregular output

Post by KeithL »

I have a battery disconnector on our Traveller which I unscrew and remove every time I park up in the garage. I also have a CTEK Comfort Indicator attached so I can monitor the battery voltage. It will remain green for weeks and weeks if we don't drive it - green is > 12.75V. The only time we had a problem was when the last battery finally lost capacity after 12 years.

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geoberni
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Re: Voltage regulator - irregular output

Post by geoberni »

KeithL wrote: Fri Nov 19, 2021 12:50 pm I also have a CTEK Comfort Indicator attached so I can monitor the battery voltage. It will remain green for weeks and weeks if we don't drive it - green is > 12.75V.
Voltage can be a very misleading measure of a battery capacity, i.e. the ability to actually do it's job.
While a terminal voltage will drop with time, and can be restored with a quick recharge, with a rechargeable battery, of any construction, the ability to deliver the required Amperage degrades, and this depends on the Depth of Discharge (DOD) cycle.
That's why any battery powered device, your phone, laptop or electric car, will need a new battery after a few years.

In addition to the DOD, the charging regime also plays an important part in determining battery lifetime. Overcharging or undercharging the battery results in either the shedding of active material or the sulfation of the battery, thus greatly reducing battery life.
The working temperature plays a significant role too. When I lived out in southern Nevada (I came back 11 years ago this week) a typical car battery only lasted about 3 years before it was totally worn out, especially if used for typical urban runs of 10 minutes each way.
My Wife's Jeep had a Voltage Display. About as much use as a Chocolate Fireguard.
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