Alternator Regulator

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emnick

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I am thinking of upgrading the regulator and cannot decide what one is best. I have looked at the search but the results were old (2005) Are they as good as the makers claim. I hope to add to the domestic battery AH next year. Looking at Adverc or Sterling. Thanks
 
Incrreasing the domestic bank capacity is the most cost-effective improvement you can make, so you should do that first. After that, adding a "smart" alternator regulator is a good idea. As an alternative, the Sterling Alternator-to-Battery Charger looks good on paper - no alternator mods needed, lower voltage charge for start battery, etc.
 
I agree with pvb if you are going to add more battery capacity then do that first. This will mean that in practical terms if you double the battery capcity then you will double the current from the alternator into the batteries. It will still tyake a long time to fully charge batteries but for a limited engine run time the total charge will be double. (Assuming batteries are only partially discharged when you start.
This is because with a regulated set voltage of 14volts the current into the battery is determined by the battery charge level. Starting at a decent current then diminishing rapidly as battery voltage rises. Add another battery and you double that current even though it will diminish. olewill
 
go with the sterling. charlie is a bloke good. adverk is old tech. before this it is best to get the right sizes of batteries for your needs. a competent cruising boat needs 300ah to 400ah minimum. more if it has lots of extras.
Kentrina
 
But hang on a mo Will ... your now charging twice the capacity so I have difficulty agreeing that you benefit from double ampage .....

And as for the other post about 300 - 400 A/Hr minimum req't - plenty of cruising boats going around with a lot less than that. It's nice if a boat has the space to fit such capacity, I know I would have difficulty fitting such amount in. My max would be about 180 - 200 A/hr unless I start to convert other stowage spaces.
 
[ QUOTE ]
But hang on a mo Will ... your now charging twice the capacity so I have difficulty agreeing that you benefit from double ampage .....

[/ QUOTE ]The benefit is very real. If you increase the charging current, you increase the number of Ah restored to the batteries in a given time. At the end of the day, it's all about putting back the Ah which have been used.
 
There seems to be some confussions as to what is being said. Doubling the battery capacity will NOT double the charging current. What it will do is double time taken to recharge unless you fit a smart charger. These "doubling" figures are of course approximations there are other factors to consider but it all gets a bit complex.
 
[ QUOTE ]
There seems to be some confussions as to what is being said. Doubling the battery capacity will NOT double the charging current. What it will do is double time taken to recharge unless you fit a smart charger. These "doubling" figures are of course approximations there are other factors to consider but it all gets a bit complex.

[/ QUOTE ]Perhaps you're confused about this. Most boat owners with 12v problems have insufficient battery capacity. The charge current is governed by the battery's ability to absorb charge. In most cases where there's insufficient battery capacity, the alternator's max output is far in excess of the battery's ability to absorb charge. So, putting some rough numbers on it, say the boat has a 70A alternator and 1 battery which will accept 20A max. In 1 hour of engine running, the alternator would put 20Ah back into the battery. If a second battery was added in parallel, both batteries would take 20A, giving 40A charge - and in 1 hour the alternator would put 40Ah back. This is a simplistic view, but the basic theory is right. Most boat owners are primarily concerned with restoring the Ah they've used in the shortest time. Having a bigger battery bank helps do that, as long as the alternator is correctly sized.
 
think of the batteries as resistors which have their part to play in governing how much current flows. Now if you put 2 resistors in parallel twice as much current flows...all else being equal.
 
I've been through the charging question and come to the conclusion that alternator regulators are not necessary if you use a VSR. This cuts out the losses through diodes and increases the effective capacity of the batteries. Plus they are easy to fit and need no internal connections to the alternator.
Incidentally, I agree with 'Refueler' 220 Ah is plenty for a cruising boat - the key thing is being able to keep it topped up.
 
Do have a look at the Balmar battery management system - I have one and it is a clever piece of gear, and totally maintenance free. It charges 2 x 130amp + 1 x 70amp batteries off a standard 55 amp alternator, which I find just fine for my crusiing needs.

NB -If you have or are thinking of a frig - that's where power drain pops up!

PWG
 
Hold on - are we forgetting that if you have one battery giving up 20AH, two batteries would only need to give up 10AH each!

Therefore, I am not so sure you would get double the current output from the alternator compared to a single battery?

Understand two resistors statement, but the voltage in the two battery set-up would not drop as much as the one battery and hence would not accept as high a charge rate?

Interesting to debate this...... /forums/images/graemlins/ooo.gif
 
Bear in mind I was contesting alan17's assertion that "Doubling the battery capacity will NOT double the charging current. What it will do is double time taken to recharge unless you fit a smart charger."

I did say "rough" numbers, and I did say it was a "simplistic" view, but it's close to reality. Fitting additional battery capacity is a great improvement.
 
Yes I do understand, I am not being contentious, I like to respectfully consider all arguments and by debating these things I believe I, and of course others, benefit. This is an intersting topic.

IMO adding battery capacity is almost always a good idea (usual caveats) and avoids deep discharging a single battery which can reduce its life.

Adding capacity means you can charge a higher current with the alternator, but surely this is if you have 'manual' or as you suggest 'intelligent' control of charging but often this is not the case. I think I feel a new thread coming on about debating and giving advice - will start it shortly! /forums/images/graemlins/smile.gif
 
I will say what I have for the last 20 years, fit the battery capacity you want with a relay split charge system, then see if you have a problem. If you don't do nothing, if you have look at correcting it.

If you have a alternator regulating around 14.2 / 14.4 volt, you will not improve reharge a great deal, if you have a alternator regulating at 13.6 volt you will improve recharge a lot with a smarter regulator. If you increase capacity you need to look at alternator output, a smart regulator will not increase current, just increase the time it charges for if you have a low voltage.

In most cases the problem is that people do not motor for long enought to recharge batteries, motoring out of the marina to open water is not normally adequate.

Brian
 
Lots of good advice above.

In my case, I have two battery banks (one twin 'domestic' and one STBD starting) with a mains charger to domestic only (OEM).

Had a problem with split diodes when the boat was just over 2 years old, easy to detect, replaced them and since then all OK (Although I hate the idea of a wasting energy due to the PD across the diodes albeit quite low around 0.6V). I will continue with this set-up unless I get another problem! (If it aint broke dont fix it...)

Would probably then look at a more intelligent charging system and like the simplicity of voltage sensing relays!

Although you can adjust the the alternator voltage which the regulator is designed to maintain (as said usually just above 14V) this can lead to over-charging on long runs, I would not advocate this mod. I would however advocate making sure that the voltage regulator +ve wire is connected to the normally lowest battery on board! /forums/images/graemlins/cool.gif
 
I have read that a standard alternator will never charge the batteries properly due to regulator set up, split charge etc. By adding batteries am I just compounding this problem. Is it not best to get the existing batteries near as possible to 100% charged. If I add batteries is there an argument that they will get damaged due to under charging? I do take your point and this could be another topic, can you get more charge /hour into AGMs Still not sure if I should go for Adverc or Sterling or Balmar
 
I guess i have to havee another go at this argument. Mostly every one is correct.
The problem is that a battery given a set regulated voltage to be charged from. takes a useful current initially which tapers to a lower current as the battery is charged. So if you run the engine just to charge the batteries you will initially get a useful current into the batteries but as the current tapers off the value of the engine run times becomes much less. It will take quite a long run to fully (or nearly fully) charge the batteries.

Now if you have 2 batteries being charged at once then (assuming the total current is less than the capability of the alternator) you get a current out of the alternator (into your batteries collectively) that is double that for one battery.

However as pointed out if you have double the battery capacity then each battery after a given overnight will only be half as discharged as if you had one battery or half capacity.

This does not mean however that being only half as discharged that the initial and subsequent current will only be half that you might expect for twice the discharge %. The problem being that inherent battery volltage which determines charge current is not a linear function of time and discharge %
So 2 batteries for a limited engine run time will replace more amp hours not actually double that for 1 battery (after a given total AH discharge) but certainly a lot more AH in if 2 batteries are charged. But of course each individual battery will be no closer to fully charged.

I think the bottom line is fit an amp meter and monitor charge current over time. This will make the whole problem more real.
What a smart charger will do is to increase the current and extend the time that the battery is charged at the higher current by increasing the regulated voltage so making a limited time engine run for charging much more productive. olewill
 
[ QUOTE ]
What a smart charger will do is to increase the current and extend the time that the battery is charged at the higher current by increasing the regulated voltage so making a limited time engine run for charging much more productive. olewill

[/ QUOTE ]

and that seems to be the crux of the whole matter, which makes it worth repeating!!
 
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