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Alternator suddently not putting out voltage... help!


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6 minutes ago, Alan de Enfield said:

 

Take out the hairdryer and the washing machine and you have the 'normal' ~100Ah per day.

 

There is a 'written' rule in boating "don't generate heat via batteries" - get Alice to cut her hair or get used to it drying naturally.

Or only run power hungry appliances when (and only when) the engine is running.

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7 minutes ago, Alan de Enfield said:

Take out the hairdryer and the washing machine and you have the 'normal' ~100Ah per day.

 

There is a 'written' rule in boating "don't generate heat via batteries" - get Alice to cut her hair or get used to it drying naturally.

Are you single by any chance @Alan de Enfield? ?

 

Sure running a hairdryer is a lot to ask of batteries. Everyone has the luxuries that they don't want to do without. Perhaps for you buying an extra panel or two and battery or two to support 5-10 minutes of hairdryer every other day would be a ludicrous idea. But if we want it, why not factor it into the calculations?

 

The washing machine will take the bulk of the load of the inverter. Fortunately mine has a "cold wash" button that turns off the heating element entirely, so it's just the motor. I think 1kW will be plenty for that.

2 minutes ago, Chewbacka said:

Or only run power hungry appliances when (and only when) the engine is running.

Yeah, at the moment we only run the fridge when the engine is running and try to do most of our device charging then too. We even try to shower while the engine is running so that the shower and water pump is getting some of the juicy alternator goodness.

 

However I'd like to get sufficient batteries so that I don't have to run the engine at all times when I am using the inverter. I know that many boaters have their inverters running constantly so I don't think it is too much to ask.

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16 minutes ago, ivan&alice said:

Are you single by any chance @Alan de Enfield? ?

 

Sure running a hairdryer is a lot to ask of batteries. Everyone has the luxuries that they don't want to do without. Perhaps for you buying an extra panel or two and battery or two to support 5-10 minutes of hairdryer every other day would be a ludicrous idea. But if we want it, why not factor it into the calculations?

 

The washing machine will take the bulk of the load of the inverter. Fortunately mine has a "cold wash" button that turns off the heating element entirely, so it's just the motor. I think 1kW will be plenty for that.

Yeah, at the moment we only run the fridge when the engine is running and try to do most of our device charging then too. We even try to shower while the engine is running so that the shower and water pump is getting some of the juicy alternator goodness.

 

However I'd like to get sufficient batteries so that I don't have to run the engine at all times when I am using the inverter. I know that many boaters have their inverters running constantly so I don't think it is too much to ask.

It isn’t so much a problem running the inverter constantly especially if it has a low power mode, it’s running it at high powers.  Having more batteries will allow either more demand before recharging or a longer period, but the problem with batteries is you can take it out much faster than you can put it back in, especially if you want max battery life, so charging to close to 100%.  It can (will) take along time.  

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51 minutes ago, Chewbacka said:

It isn’t so much a problem running the inverter constantly especially if it has a low power mode, it’s running it at high powers.  Having more batteries will allow either more demand before recharging or a longer period, but the problem with batteries is you can take it out much faster than you can put it back in, especially if you want max battery life, so charging to close to 100%.  It can (will) take along time.  

Sure, I get all that. As you can see I am calculating my power draw and will make sure I put it all back. The reason for calculating a high power day of 3.5kW is precisely so I can make sure I'm generating 3.5kW from solar 8 or 9 months of the year and the rest of the time topping up with my 50A alternator. And of course when I'm running the alternator is the time to use the washing machine and/or hairdryer. Still, if my alternator is putting out 50A max, then it's not going to run a 1500W inverter (which apparently needs about 150A?) by itself in any event, so the rest would have to come from the batteries.

 

Bearing in mind of course that this is the planning stage. I'm looking to make sure that I am speccing out the leccy to handle what we would like to run on it. And having your accurate advice on this is very welcome - even if that advice is that I'd need to double my system to run a hairdryer.

 

I haven't decided what battery technology I'm going with. Leaning towards LAs that I abuse as required and replace periodically. Either that or Li's that I coddle and can worry less about how much I'm charging them.

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7 hours ago, ivan&alice said:

 

Bearing in mind of course that this is the planning stage. I'm looking to make sure that I am speccing out the leccy to handle what we would like to run on it. And having your accurate advice on this is very welcome - even if that advice is that I'd need to double my system to run a hairdryer.

 

 

Remember the power audit of consumption can be pretty accurate but the charging calculations one gets from far too many people vastly under estimates the charging time required. Taking 50% average of alternator output is probably only good for three hours or so then using 50% starts to become more and more inaccurate by over estimating the amount of charge achieved. Li batteries are better in this respect than lead acid. I find that by far the most electrical problems are related to undercharging batteries

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15 hours ago, ivan&alice said:

Sorry to revive this old topic but I finally got around to putting that Uni-T clamp ammeter on my alternator out cable. The belt had worn through and so since my battery was over-flat (showing 11.9V) and I was mucking about with the alternator anyway, I thought it was a good time.

 

I started the engine (at normal idle revs - I don't have a rev counter) and quickly turned on everything I could in the boat. The voltmeter on my battery showed 13.9V. I measured the output cable which showed up as 47.3A and climbed to about 49.3A.

 

I measured what the boat was drawing at 6.3A.

 

Does this mean I only have a 50A alternator? Or would you expect a 70A to put out around 50A under these conditions?

Firstly if you only have 1 battery for the time being, you are not going to be able to put 70A into it. LA batteries simply don’t take that much current even when in a low SoC. The system voltage will rise until the regulator reduces the output.

 

Secondly it is worth bearing in mind that alternator regulation is pretty soft. By that I mean that if you had means to vary the load whilst watching the voltage and current and spinning the alternator fast, you would find that the alternator only produced its maximum output when the load pulls the voltage way down to the 12.somethings. With the load adjusted to get the voltage up to high 13.somethings, the current would be way down. 

 

It is not the case that an alternator will produce it’s rated output until just before the target regulated voltage is reached (14.4v or whatever) and then shuts off.

 

If you are getting 49.3A at 13.9v then your alternator is considerably more than a 50A model. But the only way to find out exactly what, is to load it such that the voltage is pulled down to 12.something.

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2 hours ago, Tony Brooks said:

Remember the power audit of consumption can be pretty accurate but the charging calculations one gets from far too many people vastly under estimates the charging time required. Taking 50% average of alternator output is probably only good for three hours or so then using 50% starts to become more and more inaccurate by over estimating the amount of charge achieved. Li batteries are better in this respect than lead acid. I find that by far the most electrical problems are related to undercharging batteries

 

26 minutes ago, nicknorman said:

Firstly if you only have 1 battery for the time being, you are not going to be able to put 70A into it. LA batteries simply don’t take that much current even when in a low SoC. The system voltage will rise until the regulator reduces the output.

 

Secondly it is worth bearing in mind that alternator regulation is pretty soft. By that I mean that if you had means to vary the load whilst watching the voltage and current and spinning the alternator fast, you would find that the alternator only produced its maximum output when the load pulls the voltage way down to the 12.somethings. With the load adjusted to get the voltage up to high 13.somethings, the current would be way down. 

 

It is not the case that an alternator will produce it’s rated output until just before the target regulated voltage is reached (14.4v or whatever) and then shuts off.

 

If you are getting 49.3A at 13.9v then your alternator is considerably more than a 50A model. But the only way to find out exactly what, is to load it such that the voltage is pulled down to 12.something.

Thanks, this all makes sense.

 

So basically the alternator output is a curve based on what the load is - I'll have to load the alternator to 70A (and spin it fast enough) to determine if it can actually produce 70A.

 

It's a bit of a moot point anyway, because in another thread it was suggested that I wouldn't be able to put a larger alternator than 70A on my engine in any event (a Beta 38 / BV1505). I think it's likely given all the evidence (including from earlier in the thread, where a very similar-looking 70A alternator was found, and from producing 50A under a 10A load with 1 LA battery in a low SoC) that the alternator is 70A and as I wouldn't be able to upgrade it. So I will work with a 50A expected generation from my alternator in my calculations.

 

That does go to show though that if I'm running a 1kW washing machine (or hairdryer) off my inverter, I'd need to be able to suck 50A out of my battery bank even while the engine is running (and 100A if it's not). So I would want to size and spec my batteries accordingly.

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40 minutes ago, ivan&alice said:

 

Thanks, this all makes sense.

 

So basically the alternator output is a curve based on what the load is - I'll have to load the alternator to 70A (and spin it fast enough) to determine if it can actually produce 70A.

 

It's a bit of a moot point anyway, because in another thread it was suggested that I wouldn't be able to put a larger alternator than 70A on my engine in any event (a Beta 38 / BV1505). I think it's likely given all the evidence (including from earlier in the thread, where a very similar-looking 70A alternator was found, and from producing 50A under a 10A load with 1 LA battery in a low SoC) that the alternator is 70A and as I wouldn't be able to upgrade it. So I will work with a 50A expected generation from my alternator in my calculations.

 

That does go to show though that if I'm running a 1kW washing machine (or hairdryer) off my inverter, I'd need to be able to suck 50A out of my battery bank even while the engine is running (and 100A if it's not). So I would want to size and spec my batteries accordingly.

I think the general feeling is that 90A alternator is the maximum one can run from a V belt, and that might be pushing it a bit. But it also depends on the belt set up and pulley sizes. If it’s the same belt that runs the water pump, the wrap won’t be as good as if it has its own dedicated belt. If the pulley ratio is such that the alternator works well at idle, this usually means the alternator pulley is quite small and again, not much length of belt wrap. If high output is the only goal then it is better to have a larger pulley on the alternator, but this of course means that the engine has to be run quite fast to get that output.

 

Also worth bearing in mind that the mechanical power delivered to the alternator is proportional to belt force x belt speed. So if the engine is running at only just enough rpm to get full output, the belt force (and hence propensity to slip and stretch) is at a maximum. If the engine is then run faster, the force on the belt reduces because, for fixed power delivery, if the belt speed increases the belt force reduces.

 

In other words, try to avoid running the engine just fast enough to produce its maximum alternator output, if belt wear and slippage is an issue.

 

On the point about the washing machine, these only use a lot of power on heat cycle. If you are avoiding a heat cycle the power consumption as an average, is not a big deal. It may momentarily take 500w or more to start the drum turning, but as an average over the wash I think it is closer to 200w or even less. We do heat the water in the washing machine using engine generated power, but once the heat/wash cycle is over, I have no qualms about stopping the engine for the subsequent rinses and spins. It’s impact on our 450AH of batteries is not significant. Anyway there is no way it uses a steady 1kw for the duration of a cold wash.

 

As to the hair dryer, unless she is Rapunzel she will only have a hair dryer on for 5 minutes max and that isn’t going to use a lot of AH. My point being that it is not just the power demand of an item that is relevant, it is also how long you intend to use it for.  1200w for 5 minutes is about 10AH. And anyway, the alternator will be able to support a good proportion of that.

 

Also worth mentioning that LA batteries are weird things! Yes it takes hours to get from 95% SoC up to 100%SoC when charging from a low SoC. But if you were at 100% SoC and you take out 5% quickly (hair dryer) and then recharge immediately, that charge goes back in quickly. All down to where you are extracting and replenishing the charge from/to - if from the “surface” of the plates, it happens quickly. But if from deeper inside the plates (because the batteries have been significantly discharged, or left a bit discharged for hours) it takes ages.

Edited by nicknorman
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31 minutes ago, nicknorman said:

I think the general feeling is that 90A alternator is the maximum one can run from a V belt, and that might be pushing it a bit. But it also depends on the belt set up and pulley sizes. If it’s the same belt that runs the water pump, the wrap won’t be as good as if it has its own dedicated belt. If the pulley ratio is such that the alternator works well at idle, this usually means the alternator pulley is quite small and again, not much length of belt wrap. If high output is the only goal then it is better to have a larger pulley on the alternator, but this of course means that the engine has to be run quite fast to get that output.

 

Also worth bearing in mind that the mechanical power delivered to the alternator is proportional to belt force x belt speed. So if the engine is running at only just enough rpm to get full output, the belt force (and hence propensity to slip and stretch) is at a maximum. If the engine is then run faster, the force on the belt reduces because, for fixed power delivery, if the belt speed increases the belt force reduces.

 

In other words, try to avoid running the engine just fast enough to produce its maximum alternator output, if belt wear and slippage is an issue.

 

My alternator is driven by a 21cm diameter pulley, 1/2" belt, and on the alternator is a 7cm pulley (3:1 ratio). That pulley and belt is not driving anything else, but there is another coaxial pulley behind it (not sure on size) that has a second belt driving another small alternator that is plugged only into the engine, and another pulley which I presume drives the cams/valves on top of the engine. I'm not sure exactly what the second small alternator is for.

Unless cruising we never run the engine faster than idle when charging, our throttle is connected to the gearbox so revving higher also engages drive.

 

I don't have any issues with slipping and stretching of the belt, but the alternator was prone to a bit of vibration due to the non-standard mounting. I got a new belt yesterday that wasn't quite the same, so I changed the mounting arrangement somewhat to get it to fit and it has had the happy side effect of cutting all vibration out.

 

There's also quite a bit of soot in the alternator from a past exhaust leak. I cleaned up the housing and got as deep into the vanes as I could, but I'm sure the alternator's cooling fan has drawn a lot of muck into it. I was tempted to try to clean it but as it is still performing well I decided not to fix things that ain't broke.

 

40 minutes ago, nicknorman said:

On the point about the washing machine, these only use a lot of power on heat cycle. If you are avoiding a heat cycle the power consumption as an average, is not a big deal. It may momentarily take 500w or more to start the drum turning, but as an average over the wash I think it is closer to 200w or even less. We do heat the water in the washing machine using engine generated power, but once the heat/wash cycle is over, I have no qualms about stopping the engine for the subsequent rinses and spins. It’s impact on our 450AH of batteries is not significant. Anyway there is no way it uses a steady 1kw for the duration of a cold wash.

 

As to the hair dryer, unless she is Rapunzel she will only have a hair dryer on for 5 minutes max and that isn’t going to use a lot of AH. My point being that it is not just the power demand of an item that is relevant, it is also how long you intend to use it for.  1200w for 5 minutes is about 10AH. And anyway, the alternator will be able to support a good proportion of that.

Yes I got this washing machine mainly on the advice of the Cruising the Cut guy ( https://www.youtube.com/watch?v=X6FT0zzpN_k ), who raved about the true cold wash button. I've placed the washing machine right next to the cauliflower and intend to install a thermostatic valve so I can put hot water into it (I know cold is OK but I just feel that hot gets the clothes cleaner).

 

He didn't know how much the washing machine draws without the heating element, it's good to know that 1000W is probably overly pessimistic. If I can refine my estimate down to 500W or even 200W that is great, I do want to maintain a healthy level of pessimism in these calculations as I see people (myself included) constantly berated on this forum for being overly optimistic with their leccy calculations!

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44 minutes ago, nicknorman said:

I think the general feeling is that 90A alternator is the maximum one can run from a V belt, and that might be pushing it a bit.

 

There seems to be two widths of V belt widely available from places like Bearing Boys, 9mm and 12mm IIRC. Each will run after a fashion in a pulley designed for the other, again IIRC and they are often mixed up.

 

It the 90A rule of thumb for a 9mm belt or a 12mm belt, does anyone know?

 

Should more attention should be given to pulley widths or are pulleys actually designed to suit both belt widths?

 

 

 

 

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12 minutes ago, ivan&alice said:

Unless cruising we never run the engine faster than idle when charging, our throttle is connected to the gearbox so revving higher also engages drive.

You should have a 'button' that allows you to run the engine at high revs without engaging gear.

 

On some controls it can be :

 

A button / tab that you press down to disengage the gear cable

A rubber button in the centre of the controller 'pivot' point (see picture - position E)

Pull the lever 'outwards' to disengage to gear cable.

It can be a 'squeeze' lever underneath the main handle (see picture Item D)

 

Do you always start your engine without 'any revs' (throttle) ?

 

0176917_F2.jpg

 

 

On this type, the complete 'handle' pulls a few mm 'away' from the box to disengage the gears

 

Image result for outboard control gear disengage

Edited by Alan de Enfield
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21 minutes ago, ivan&alice said:

My alternator is driven by a 21cm diameter pulley, 1/2" belt, and on the alternator is a 7cm pulley (3:1 ratio). That pulley and belt is not driving anything else, but there is another coaxial pulley behind it (not sure on size) that has a second belt driving another small alternator that is plugged only into the engine, and another pulley which I presume drives the cams/valves on top of the engine. I'm not sure exactly what the second small alternator is for.

Unless cruising we never run the engine faster than idle when charging, our throttle is connected to the gearbox so revving higher also engages drive.

 

I don't have any issues with slipping and stretching of the belt, but the alternator was prone to a bit of vibration due to the non-standard mounting. I got a new belt yesterday that wasn't quite the same, so I changed the mounting arrangement somewhat to get it to fit and it has had the happy side effect of cutting all vibration out.

 

There's also quite a bit of soot in the alternator from a past exhaust leak. I cleaned up the housing and got as deep into the vanes as I could, but I'm sure the alternator's cooling fan has drawn a lot of muck into it. I was tempted to try to clean it but as it is still performing well I decided not to fix things that ain't broke.

 

Yes I got this washing machine mainly on the advice of the Cruising the Cut guy ( https://www.youtube.com/watch?v=X6FT0zzpN_k ), who raved about the true cold wash button. I've placed the washing machine right next to the cauliflower and intend to install a thermostatic valve so I can put hot water into it (I know cold is OK but I just feel that hot gets the clothes cleaner).

 

He didn't know how much the washing machine draws without the heating element, it's good to know that 1000W is probably overly pessimistic. If I can refine my estimate down to 500W or even 200W that is great, I do want to maintain a healthy level of pessimism in these calculations as I see people (myself included) constantly berated on this forum for being overly optimistic with their leccy calculations!

The second smaller alternator connects to the engine battery for charging it. It is probably 45A. This ensure separation between the engine battery and the domestic batteries. However there are other ways to achieve that, such as a voltage sensitive relay (VSR) which connects the batteries together when the engine is running and charging, and disconnects them when the engine stops. If it were my boat, I would connect both alternators to the domestic batteries and connect a VSR between the domestic and starter batteries. That way you get to use the output from the smaller alternator as well. As thing stand, that alternator is doing virtually nothing as it will have replenished the starter battery within a minute or two of the engine starting, after that it is doing nothing.

 

Regarding the second belt you mention, this is driven by the crank shaft and also runs the engine cooling water pump (not the camshaft!)

 

On the throttle lever thing, there will be a means to operate the throttle without it going into gear. Sometimes a button to push in or pull out, sometimes you move the whole lever sideways, it depends on the exact model. A photo or product name will allow us to tell you how to do that. Starting the engine from cold at idle to charge the batteries is not good for it. Much better to run the engine at fast idle say around 1200rpm, at least to start with until the charge current decreases.

 

The “soot” you refer to is almost certainly black belt dust, arising in part because you are running the engine too slowly at high charge currents. It does look a bit like soot but is actually rubber dust. And of course means the belt is slipping and wearing.

Edited by nicknorman
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4 hours ago, Alan de Enfield said:

You should have a 'button' that allows you to run the engine at high revs without engaging gear.

 

Do you always start your engine without 'any revs' (throttle) ?

Of course! I actually knew that... but I just never use it so I forgot.

 

Yes we always start the engine with no throttle.

 

The ignition turns to the left against a spring, and doing this for a few seconds warms the engine - I presumed they were glow plugs. The engine always starts very easily and quickly, if we don't warm it, it takes a couple of seconds and there will be a brief puff of smoke which I presumed was unburnt diesel. But, the engine has been fantastic over the last year, starting and running without any complaints.

 

4 hours ago, nicknorman said:

The second smaller alternator connects to the engine battery for charging it. It is probably 45A. This ensure separation between the engine battery and the domestic batteries. However there are other ways to achieve that, such as a voltage sensitive relay (VSR) which connects the batteries together when the engine is running and charging, and disconnects them when the engine stops. If it were my boat, I would connect both alternators to the domestic batteries and connect a VSR between the domestic and starter batteries. That way you get to use the output from the smaller alternator as well. As thing stand, that alternator is doing virtually nothing as it will have replenished the starter battery within a minute or two of the engine starting, after that it is doing nothing.

I installed a split charge relay to charge the starter battery and then the domestic. When I bought the boat the seller (by agreement) kept his Li's, so we had no electrics hooked up until I bought the LA and split charge relay.

 

Can I just connect the smaller alternator in parallel straight to where the main alternator joins the battery bank?

 

4 hours ago, nicknorman said:

Starting the engine from cold at idle to charge the batteries is not good for it. Much better to run the engine at fast idle say around 1200rpm, at least to start with until the charge current decreases.

 

The “soot” you refer to is almost certainly black belt dust, arising in part because you are running the engine too slowly at high charge currents. It does look a bit like soot but is actually rubber dust. And of course means the belt is slipping and wearing.

So when starting the engine with a flat battery bank, you're supposed to give it some throttle for the first say 10 minutes?

 

There may well be black rubber dust as well, but believe me you wouldn't be able to tell because the whole engine bay is coated in a film of diesel soot from my exhaust leak. I'm actually busy cleaning it out today.

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57 minutes ago, ivan&alice said:

 

 

Can I just connect the smaller alternator in parallel straight to where the main alternator joins the battery bank?

 

Yes. However, make sure that the VSR closes when the engine is started, or shortly afterwards. Some VSRs only sense the voltage on one side and if that is connected to the engine battery side, it will never close. 

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1 hour ago, ivan&alice said:

 

Yes we always start the engine with no throttle.

 

So when starting the engine with a flat battery bank, you're supposed to give it some throttle for the first say 10 minutes?

Yes. If you look at the Beta owner’s manual it says to start with 1/3rd throttle. That is perhaps rather a lot IMO, but to start at idle puts maximum stress on belts, pulleys, crankshaft etc and probably doesn’t spin the alternator fast enough to get maximum output or good cooling air flow.

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3 hours ago, nicknorman said:

Yes. If you look at the Beta owner’s manual it says to start with 1/3rd throttle. That is perhaps rather a lot IMO, but to start at idle puts maximum stress on belts, pulleys, crankshaft etc and probably doesn’t spin the alternator fast enough to get maximum output or good cooling air flow.

Alright, good to know! I will open the throttle in future when starting the engine. Should you open the throttle first and then turn on, or turn on then open the throttle? Must I still use the ignition to the left warming first? (the thing that I think is glow plugs).

I can imagine the extra stress on the alternator and belt from having a high load (therefore requiring more force to turn the alternator), but the engine doesn't labour in any way when I turn it on.

After how long at 1/3 throttle should I put the engine back into tickover? Unfortunately I don't have a rev counter.

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3 minutes ago, ivan&alice said:

Should you open the throttle first and then turn on, or turn on then open the throttle?

The former. 
 

3 minutes ago, ivan&alice said:

Must I still use the ignition to the left warming first? (the thing that I think is glow plugs).

Yes. And yes, it’s glow plugs. 
 

4 minutes ago, ivan&alice said:

After how long at 1/3 throttle should I put the engine back into tickover?

See if dropping the revs also drops the current. If it does then keep the revs up until it doesn’t. If you don’t have an ammeter then fit one :)  (in the mean time use your clamp meter). 

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18 minutes ago, ivan&alice said:

Alright, good to know! I will open the throttle in future when starting the engine. Should you open the throttle first and then turn on, or turn on then open the throttle? Must I still use the ignition to the left warming first? (the thing that I think is glow plugs).

I can imagine the extra stress on the alternator and belt from having a high load (therefore requiring more force to turn the alternator), but the engine doesn't labour in any way when I turn it on.

After how long at 1/3 throttle should I put the engine back into tickover? Unfortunately I don't have a rev counter.

Throttle first before operating the starter. But not too much - just so the engine is running at a fast idle, not racing away. Yes might as well use the glow plugs, especially in cold weather.

 

How long depends on charging current, but I’d leave it for 15 mins or so.

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  • 6 months later...

Reviving this old thread again.

 

Yesterday and today I installed 1.5kW of solar via a Victron MPPT 250 / 100 charge controller. Also added a BMV 712 which I'm not completely sure how to read yet, throughout the day the sun is charging my battery.

 

This morning the alternator was putting out 14.2V just fine. Now as the sun goes down and I'm heating water for a shower by running the engine, I'm getting no voltage - I'm stuck on 12.4. I put my Uni-T clamp meter on the alternator cable and I'm getting no ants either - none. Tightened the belt to no avail. Less of an emergency this time because the sun will keep me charged, but just my luck if tomorrow is overcast and I'm stuck without any power.

 

I'm still using my LA battery, as I unfortunately have to wait for less pandemicky times to get my LiFePOs from Jeremy.

 

On 01/06/2019 at 01:07, TheBiscuits said:

I'll punt that the *one* 110Ah battery you have been using for 6 months as your only battery is sulphated to hell and is only fit for weighing in for a tenner.

 

Yes - this same 110Ah battery! It's served me well for nearly two years and I've never noticed anything wrong with it. But perhaps this is the dreaded plate short suggested way back last June.

 

Could current from the solar have messed anything up? 1.5kW on a 110Ah battery seems like that might have been a bad idea.

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I have never had a working set of engine lights. I was indeed cleaning around the engine wiring - the wires had all been  wrapped a generation ago with black electrical tape which had melted into a gooey mess. Someday I'd like to fix all that but it isn't a priority at the moment. I definitely did a lot of tugging and pulling but not since this morning, when everything was working as it should. And I'm fairly sure the alternator wires are OK.

 

The alternator has three terminals but only two cables - a thick red one (25mm^2 ish) and a teeny green and yellow one (2mm^2 ish).. I'm guessing its negative is the engine block, since I can't understand how a current could be that asymmetric.

 

Tomorrow I'll use a meter to test that both cables are intact. Not sure what else to try.

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1 minute ago, ivan&alice said:

Someday I'd like to fix all that but it isn't a priority at the moment.

 

I've an idea that might have just changed!

 

 

2 minutes ago, ivan&alice said:

The alternator has three terminals but only two cables - a thick red one (25mm^2 ish) and a teeny green and yellow one (2mm^2 ish).. I'm guessing its negative is the engine block, since I can't understand how a current could be that asymmetric.

 

A photo of the back of the alternator would be really good now.

 

 

 

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