Another Charging Question?

[Dougal]

Switching from wind generator to solar panels, but now also wondering about those 'Advanced Alternator Regulator' thingies (technical term), like Sterling make. I have a Perkins 4108 in a motor sailor, with an alternator that I 'THINK' will put out up to 80 Amps. Don't really understand those gizmos (another technical term), so wondering if it might be an investment or a waste of money for me.

Under what sort of circumstances would they benefit my charging system?

 

[Colin Regs]

http://www.amazon.co.uk/Boatowners-Mechanical-Electrical-Manual-Essential/dp/0713672269/ref=sr_1_1?ie=UTF8&qid=1428263974&sr=8-1&keywords=nigel+calder+books

It's not a simple thing to understand.

 

[Poecheng]

If you have a Perkins 4108 then you will benefit because the alternator will be older style and the built in regulator will not charge the batteries as well as it might do.

May I suggest an Adverc rather than a Sterling.

There is a little wiring but nothing too daunting apart from one bit. The alternator needs to be removed and a wire soldered on to the bushes (from recollection). If you cannot do this then someone will help you even if it is an auto electrician. Then it is a matter of mounting the Adverc unit, connecting up the wiring harness (connections to the new wire, alternator and battery) and plugging it into the Adverc unit.

It works by considering the (actual) voltage at the battery and not assuming there is no voltage drop from cable, connections or such things as split charging diodes. It therefore alters the alternator to put out such a voltage at the alternator as ensures the correct voltage at the battery; for example with a split charging diode in your system the alternator voltage may be 17.5v to ensure the correct 14.4v is at the battery terminals.

It will make a large difference and will ensure that your batteries are fully charged and in a shorter time. It does not force-charge them, just ensures that the alternator does what a good modern charger would do. You can hear the difference because after about 5 minutes after the engine starts (soft start of the Adverc), the Adverc "kicks in" and the revs drop as the power is drawn from the alternator. After about 20m it backs off, checks and then starts again.

Put a high quality alternator belt on.

All IMHO

 

[Dougal]

Thanks for the detailed reply. However, it's NOT the original alternator with external regulator. I blew that up years ago. I had a high output unit fitted about 5 years ago. The mechanic cut out the old regulator.

 

[Poecheng]

Hi Dougal,

It is still all dependant upon the regulator - which now appears to be an internal regulator. I had assumed it was an internal regulator as I didn't realise the 4108 has an external one originally - I know of the engine but before my time

It may be fine (ish) if it is sticking over 14.2v at the battery terminals and not just in the first ten minutes. Unless you monitor the voltage accurately over some time it is difficult to say whether it is good enough; even then it is simplistic even if it is better than older style regulators. That it is good enough does not mean that it cannot be improved and every specialist manufacturer has external, microprocessor controlled regulation [Balmar, Adverc, Mastervolt] and I believe this is because you simply cannot put the brains into an internal regulator which are made in their millions for tuppence for the car market.

If you have a high output alternator then it is highly likely it would benefit from external regulation - as said my preference is for Adverc and they can be picked up second-hand occasionally. A Balmar regulator is more expensive and, I believe, equally as good as well as being user adjustable.

 

[Colin Regs]

With apologies for the brevity of my earlier reply...

Before adding another 'gizmo' to the electrical system, I would really recommend that you do try to get to grips with it. Nigel Calder's book begins with the importance of establishing a balanced electrical system which suits your boat's needs. If you haven't done that, then adding more bits of expensive kit is unlikely to take you any closer to an appropriate 'fit-for-purpose' system. That's why I'd make a start on his weighty tome...

 

[sailorman]

i bought a adverc from a forumite & phoned adverc 3 times, they were very helpful even though i hadnt bought new. the adverc is just brilliant.

 

[pvb]

However, it's NOT the original alternator with external regulator. I blew that up years ago. I had a high output unit fitted about 5 years ago.

You need to use a digital voltmeter to accurately measure the charging voltage at the battery terminals. If it's 14.2 to 14.4 volts, you probably won't get a big improvement with an add-on regulator (although to some extent this depends on what type of batteries you have). You might also check whether the alternator has a remote sensing lead connected to the batteries - this will improve the voltage reaching the batteries.

 

[RobbieW]

By a strange coincidence Adverc for sale

 

[sailinglegend420]

.....If it's 14.2 to 14.4 volts, you probably won't get a big improvement with an add-on regulator (although to some extent this depends on what type of batteries you have)......

I would challenge this thinking BIG TIME! All boats will see a big improvement.

Boats with a more modern 14.2-14.4 volt alternator with a built-in regulator will have a simple temperature sensor which will unnecessarily drop the output voltage down well below the 14.4v gassing voltage - it thinks the battery is close by in the engine compartment so it lowers the voltage to avoid gassing as the battery heats up. This is great in a car but it is very dumb on a boat where the batteries should not be in the engine compartment. An automotive alternator will also get very much hotter than in a car because it is being asked to charge a large house battery for long periods. All this will make the alternator temperature sensor drop the voltage probably well below 14v.

A good external regulator will have a battery temperature sensor and a voltage sensor actually on the battery and control the charging voltage to charge the battery faster. It will help reduce overcharging due to excessive gassing, and reduce undercharging due to bad voltage and temperature regulation. It will also reduce the output voltage to a Float mode when the battery is fully charged to prolong the battery life.

So there are many very good reasons why you should fit a good external regulator, even if your internal regulator is producing 14.4 volts or higher.

1. It will have multi-stage voltage settings for different battery types.

2. It should also be custom programmable to match the alternator and battery bank sizes. There are so many ‘new’ batteries now that don’t fit the standard charging profiles. Balmar's regulators allow many parameters to be changed, for example they may set the Boost voltage to 14.6v, hold that for 45 minutes and then reduce it to 14.3v, just below the gassing voltage, and hold it there for the duration of the absorption stage. They can be programmed to stay longer in the absorption stage without dropping down to float too early to get the batteries close to 100% charged.

It is worth noting that with sealed batteries most battery manufacturers recommend that you use a multi-stage regulator to drop the charge down to float mode at 13.2-13.8 volts to avoid gassing and overcharging. This is a condition of the warranty on some batteries.

3. It will delay the charge current for about a minute at start up until the engine oil is well distributed. A 100 amp alternator draws 4 HP which is a heavy load on an engine when starting with a weak battery.

4. It will also accept a sensor to measure the alternator temperature and control the charge rate. Even a 100 amp alternator could be providing 15 amps to the boat systems, another 25 amps to say a watermaker or an inverter, and then a heavily discharged bank may be demanding 50 or 60 amps. In this situation the batteries may not get charged and the alternator will overheat and burn out from continually trying to deliver its maximum output if not protected by a temperature sensor. It is too easy for the alternator on a boat to get too hot if used for long periods.

5. It will also accept a sensor to measure the battery temperature which will rise with a heavy charge current. At 25ºC batteries start to gas at 14.4v, at 40ºC they gas at 14v so the external regulator will reduce the charging voltage automatically to compensate for this. If batteries are fitted in an engine compartment it is very easy for them to get too hot and lose water. This is fatal for sealed batteries. Sailing in high temperature regions may mean the batteries are already at 30C before charging starts.

6. It will have a voltage sensor at the batteries not on the alternator. This will compensate for split diodes or losses on cable runs to the battery.

7. A Balmar regulator has a “small engine mode” that allows you to cut the output to 50% with a switch to reduce the alternator load on the engine when you suddenly need extra power in a big sea. It also has belt manager to reduce the load on the alternator. A 100 amp alternator set to 70% will run cooler and produce 70 amps at a lower speed.

 

[grumpygit]

I would challenge this thinking BIG TIME! All boats will see a big improvement.

Boats with a more modern 14.2-14.4 volt alternator with a built-in regulator will have a simple temperature sensor which will unnecessarily drop the output voltage down well below the 14.4v gassing voltage - it thinks the battery is close by in the engine compartment so it lowers the voltage to avoid gassing as the battery heats up. This is great in a car but it is very dumb on a boat where the batteries should not be in the engine compartment. An automotive alternator will also get very much hotter than in a car because it is being asked to charge a large house battery for long periods. All this will make the alternator temperature sensor drop the voltage probably well below 14v.

A good external regulator will have a battery temperature sensor and a voltage sensor actually on the battery and control the charging voltage to charge the battery faster. It will help reduce overcharging due to excessive gassing, and reduce undercharging due to bad voltage and temperature regulation. It will also reduce the output voltage to a Float mode when the battery is fully charged to prolong the battery life.

So there are many very good reasons why you should fit a good external regulator, even if your internal regulator is producing 14.4 volts or higher.

1. It will have multi-stage voltage settings for different battery types.

2. It should also be custom programmable to match the alternator and battery bank sizes. There are so many ‘new’ batteries now that don’t fit the standard charging profiles. Balmar's regulators allow many parameters to be changed, for example they may set the Boost voltage to 14.6v, hold that for 45 minutes and then reduce it to 14.3v, just below the gassing voltage, and hold it there for the duration of the absorption stage. They can be programmed to stay longer in the absorption stage without dropping down to float too early to get the batteries close to 100% charged.

It is worth noting that with sealed batteries most battery manufacturers recommend that you use a multi-stage regulator to drop the charge down to float mode at 13.2-13.8 volts to avoid gassing and overcharging. This is a condition of the warranty on some batteries.

3. It will delay the charge current for about a minute at start up until the engine oil is well distributed. A 100 amp alternator draws 4 HP which is a heavy load on an engine when starting with a weak battery.

4. It will also accept a sensor to measure the alternator temperature and control the charge rate. Even a 100 amp alternator could be providing 15 amps to the boat systems, another 25 amps to say a watermaker or an inverter, and then a heavily discharged bank may be demanding 50 or 60 amps. In this situation the batteries may not get charged and the alternator will overheat and burn out from continually trying to deliver its maximum output if not protected by a temperature sensor. It is too easy for the alternator on a boat to get too hot if used for long periods.

5. It will also accept a sensor to measure the battery temperature which will rise with a heavy charge current. At 25ºC batteries start to gas at 14.4v, at 40ºC they gas at 14v so the external regulator will reduce the charging voltage automatically to compensate for this. If batteries are fitted in an engine compartment it is very easy for them to get too hot and lose water. This is fatal for sealed batteries. Sailing in high temperature regions may mean the batteries are already at 30C before charging starts.

6. It will have a voltage sensor at the batteries not on the alternator. This will compensate for split diodes or losses on cable runs to the battery.

7. A Balmar regulator has a “small engine mode” that allows you to cut the output to 50% with a switch to reduce the alternator load on the engine when you suddenly need extra power in a big sea. It also has belt manager to reduce the load on the alternator. A 100 amp alternator set to 70% will run cooler and produce 70 amps at a lower speed.

Good info.

I am 24v with a stand alone service alternator with a 29v regulator fitted with which I use the Driftgate Bucaneer and find it does all our needs.