Alternator charging problem.

[nutmeg]

I am having problems charging my domestic batteries using my alternator and would appreciate any help.

 

My system comprises

 

Beta 1903 engine driving 95 amp alternator with Balmar Controller, (alternate charging provided by Kohler 3.5 KVA marine generator and Victron Phoenix Multi Inverter/charger)

 

A few weeks ago my BMV 501 battery monitor indicated charging had stopped whilst we were travelling, the batteries being nowhere near fully charged. The warning lamp to the domestic system was not lit.

 

The Balmar controller, which has a digital display which I believe indicates all sorts of useful things if you understand them, was displaying its normal readings (being complicated and electronic it of course goes wrong occassionally, but then the red 'no charge' warning light illuminates and the readings change. Switching off the engine unplugging the Balmar and reconnecting usually works)

 

I did the usual things like checking the alternator belt for slippage, connections, as far as possible, but could not find an obvious fault there.

 

The next day when I started the engine, charging did not commence after the usual delay, however when I increased the revs to much higher than normal, i.e 2500-3000 rpm, charging started, albeit at first in an off and on sort of way, and would continue charging if revs were slowly reduced.

 

All was well for a few days until in a series of locks, where revs were naturally low for some time, charging failed again.

 

The same pattern has repeated several times, however I cannot now get charging at all from the alternator although everthing is fine using the generator.

 

Knowing very little about narrowboat electrical systems I have followed the fault finding procedure in the Balmar manual.

 

It suggests an alternator/regulator field test by checking for a strong magnetic pull on the pulley shaft when ignition switched on, engine not started. After usual delay strong magnetism was noted and strangely, as the regulator started, the 'no charge' warning light came on, something it has not been doing, except for a few seconds when the ignition is first turned on.

 

Next it suggests a voltage regulator test by using a multimeter, taking readings from the sensing, field and ignition wires in the plug connecting the balmar controller to the alternator. Readings are taken at three stages, with ignition off, ignition on engine off and lastly while engine running at 1400 rpm. Readings were as suggested they should be except the red sensing wire only showed the battery voltage at each stage (12.2 volts at the time) and should have been higher with the engine running.

 

At this point I do not know what to do next, except of course consult a marine electrical engineer which I may have to do but I wonder if anyone can suggest anything else I can try.

[bottle]

As a totally non expert.

 

I think you have proved that the alternator either needs a service or replacement.

 

As long as all connections are clean and tight.

[Sir Nibble]

Sorry to be brief, busy busy busy. Sounds to me that there is a problem between the alternator output and the battery. Your location? There are a couple of professionals on this board and you may be just up the cut from one of them.

[nutmeg]

Sorry to be brief, busy busy busy. Sounds to me that there is a problem between the alternator output and the battery. Your location? There are a couple of professionals on this board and you may be just up the cut from one of them.

 

Thanks for the reply.

 

We are currently on the Trent and Mersey just south of Stoke on Trent, heading towards the Coventry and South Oxford en route to the Thames. If anyone knows a good electrical expert on the way I would be grateful for contact details but meantime whilst we sit out the rain due tomorrow I will check those connections again.

[Arnot]

Thanks for the reply.

 

We are currently on the Trent and Mersey just south of Stoke on Trent, heading towards the Coventry and South Oxford en route to the Thames. If anyone knows a good electrical expert on the way I would be grateful for contact details but meantime whilst we sit out the rain due tomorrow I will check those connections again.

Sounds like it might be the brushes in the alternator.

 

If it helps I am based in Stone and you should be fairly near me...

 

Regards

 

Arnot

[Sir Nibble]

There you go, three different replies and three different diagnoses, shows how difficult it is to help by sitting at a keyboard!

For what it's worth, I have spent 35 years as a vehicle and marine electrical professional, and I would certainly trust Arnot with the job so I suggest you arrange to meet up with him.

[nutmeg]

Thanks for all the advice and it's a particularly big thanks to Arnot for turning out at short notice and driving down to Fradley Junction to sort us out (we had reached there before I managed to read the message that he is based in Stone, where we passed through the day before yesterday !)

 

It turns out the alternator needs serious attention and not just new bushes, so he has taken it away for repair. Fortunately as we have a separate generator/charger system for the domestic batteries he was able to leave the alternator cables safely isolated so we can continue our journey to Maidenhead, hoping to get there before our daughter has her first baby, due mid August.

[Smelly]

A bleedin good example of why this board is so good!

 

Arnot...

[sociable_hermit]

Yep, Arnot has helped me out a great deal too, will PM when next approaching Stone in order to arrange beers!

[Bobbybass]

I am having problems charging my domestic batteries using my alternator and would appreciate any help.

 

My system comprises

 

Beta 1903 engine driving 95 amp alternator with Balmar Controller, (alternate charging provided by Kohler 3.5 KVA marine generator and Victron Phoenix Multi Inverter/charger)

 

A few weeks ago my BMV 501 battery monitor indicated charging had stopped whilst we were travelling, the batteries being nowhere near fully charged. The warning lamp to the domestic system was not lit.

 

The Balmar controller, which has a digital display which I believe indicates all sorts of useful things if you understand them, was displaying its normal readings (being complicated and electronic it of course goes wrong occassionally, but then the red 'no charge' warning light illuminates and the readings change. Switching off the engine unplugging the Balmar and reconnecting usually works)

 

I did the usual things like checking the alternator belt for slippage, connections, as far as possible, but could not find an obvious fault there.

 

The next day when I started the engine, charging did not commence after the usual delay, however when I increased the revs to much higher than normal, i.e 2500-3000 rpm, charging started, albeit at first in an off and on sort of way, and would continue charging if revs were slowly reduced.

 

All was well for a few days until in a series of locks, where revs were naturally low for some time, charging failed again.

 

The same pattern has repeated several times, however I cannot now get charging at all from the alternator although everthing is fine using the generator.

 

Knowing very little about narrowboat electrical systems I have followed the fault finding procedure in the Balmar manual.

 

It suggests an alternator/regulator field test by checking for a strong magnetic pull on the pulley shaft when ignition switched on, engine not started. After usual delay strong magnetism was noted and strangely, as the regulator started, the 'no charge' warning light came on, something it has not been doing, except for a few seconds when the ignition is first turned on.

 

Next it suggests a voltage regulator test by using a multimeter, taking readings from the sensing, field and ignition wires in the plug connecting the balmar controller to the alternator. Readings are taken at three stages, with ignition off, ignition on engine off and lastly while engine running at 1400 rpm. Readings were as suggested they should be except the red sensing wire only showed the battery voltage at each stage (12.2 volts at the time) and should have been higher with the engine running.

 

At this point I do not know what to do next, except of course consult a marine electrical engineer which I may have to do but I wonder if anyone can suggest anything else I can try.

Hi...

I did have a problem like this when my engine start battery was on its way out.

It 'dominated' the charging of the domestic batteries and my Sterling system showed no charging going on...or very low amps...even though they needed it.

My main battery guage (simple round type) showed alternator output as only about 12.2v instead of the normal 13/14 that I am used to.

Changing the troublesome battery sorted it out.

[Arnot]

Yep, Arnot has helped me out a great deal too, will PM when next approaching Stone in order to arrange beers!

Thanks for the compliments - appreciated!

 

When I cought up with Nutmeg there was no output from the alternator and metering it produced some strange results on the field resistance. Anyway, since there was a mains generator with a Victron 120A charger and the domestic alternator could be removed and the engine still run, that's what I did. After tea and butties (thanks), they are now on their way to London.

 

It turns out that this alternator is a Balmar special and was eventually stopped by a rather unusual fault, one rotor coil wire had a dry/broken solder joint to the slip ring... However, the whole machine is pretty badly worn and probably not worth repairing so I am going to see if I can find a replacement. As well as the rotor fault, the stator wires have melted the solder joints on the rectifier that have then arced and melted the plastic rectifier plate.

 

The trouble is that the alternator that Balmar used for their conversion is quite an old bosch design (last fitted to a vehicle over 20 years ago to my knowledge) so it might not be so straightforward.

 

I will post the outcome.

 

Kind regards

 

Arnot

[Sir Nibble]

That's interesting, all those joints de-soldering like that, might be worth a regulator test when it's all back together. Have you investigated Wood auto to spec parts or to source the core unit?

[Arnot]

That's interesting, all those joints de-soldering like that, might be worth a regulator test when it's all back together. Have you investigated Wood auto to spec parts or to source the core unit?

I agree and it will certianly be worth keeping an eye on the regulator. I suspect that the problem with the solder joints is a combination of;

1) old age

2) that these joints were always the achilles heel of this type of alternator. When I used to rebuild these units I remember that great care had to be taken with these joints.

3) that the Balmar regulator maintains a higher initial charge rate for longer leading to very high alternator temperatures

4) that the boat is a semi- trad with very limited engine hole cooling

and last but not least

5) that nutmeg has recently invested in a new set of AGM batteries. Whilst these are very good, their low internal resitance will tend to take a bulk charge for longer than most which in turn compounds the problems listed in the first four points.

 

It is all best guess stuff though really...

 

I did look at getting the bits and rebuilding it but since the Balmar version cannot be identified to a Bosch part number, it is a bit pot luck on what to orde. Also, by the time that the rotor is repaired with new slip rings, the stator, rectifier, brush box and bearings replaced it would almost certianly be beyond economical repair...

 

Regards

 

Arnot