Increasing voltage output from alternator on 1GM10

[Chris_Robb]

James - I agree with what you are saying re Alternator controllers and VSRs, BUT:

Surely this is only true with a modern alternator that puts out up to 14.8V? My own set up on an Oceanlord, with a battery switch 1,2 or both, initially only gave me 13.8V when charging and a trickle of 2-8 amps into the battery. So fitting a Sterling controller on this raises the voltage to 14.8 and allows the alternator (50amps) to output an initial 45amps, dropping eventually to around 15amps when I stop charging. I do need to keep an eye on the water levels and top up regularly.

Perhaps I am working the alternator too hard and it will overheat???

 

[Ken_Irby]

Some comments on this response

Most who post here i assume don't make a point of displaying their companies' website addresses. also we too "post in our lunch-hours" out of interest and a desire to help our fellow "practical boat owners".
if you have a single acting vsr and solar panels, after switching off the engine, unless this also disconnects the charging feed to the starter battery, the voltage provided to the now linked batteries by the solar panels will ensure that the relay remains closed so the solars will continue to charge everything. when night falls, the solar panel voltage will drop off and the two banks will disconnect safely at 12.7v. most solar panels also have an in-line regulator which incorporates a diode to prevent the overnight reverse-charging phenomenon. you don't need a double acting vsr in this case unless you don't start the engine each morning but even it isn't all that vital since the then isolated starter battery, if healthy will hold it's charge sufficiently to start the engine and ALL the solar charge will go into the house bank where, particulary out here, the fridge needs every watt it can get!
this next statement alarms me somewhat "Not many people know this but if you are using a blocking diode in combination with an alternator charge controller, it is quite possible to overcharge and damage your engine battery bank." it would appear that you are suggesting that larger capacity batteries require larger charging voltages and that somehow a (healthy) starter battery will be damaged by it being charged in parallel to a larger capacity one. the truth is that once it has reached it's capacity the smaller battery will simply not take any further charge. this is not unique to diode seperated systems, which actually reduce the alternator's output voltage as applied to the battery but also to your beloved vsr which holds the batteries directly in parallel so long as the input is >12.7v. you don't condemn vsrs for the same "disadvantage". why?
most people will already have a diode splitter so you aren't selling one against the other, only a vsr against no sale.
your comments on vsr chatter remind me of a conversation i once had with the (i'm very sorry to hear) late John Heap of adverc where he related a story about vsrs melting due to this effect in a fleet of ambulances, previously so fitted, which he was asked to look at. incidentally, he also stated that his device was not any sort of booster like Charles Sterling's but simply a machine to battery sensing conversion device. and yes HIS device DID shorten charge times "marginally" but on a timed, not a monitored basis
incidentally, i notice how much you go out of your way to avoid mentioning Mr Sterling and his products. is the feude still going on? funny that you decided to bring out your own multi-stage controller after you and your father had spent all those years decrying a very innovative product and company which has been awarded a Queen's Award to Industry for such items.
furthermore, throughout the whole of your response you continually ignore the fact that the car type alternators fitted to most marine engines are just not suitable for their purpose in sailing boats not relying on shore power which require a device to re-plenish, depleted overnight or whilst sailing, batteries, where a machine (load) sensing device is just not good enough but where battery sensing is vital and a much reduced charging time where the alternator's health is monitored is desirable.
finally, if you are against high charging voltages and stepped charging devices, why do you sell Dolphin mains chargers which initially put in excess of 16.5 volts across all the batteries (ok a small arguement for plate cleaning once in a while) and continue to bash voltages like sterling's device does but for a fixed length of time regardless - unlike his which is monitored and varies this time to suit battery state and then, like his goes into float for the remainder of the time connected. why is your blind french system ok but his intelligent one not?
Chas via Kentrina's link

 

[Chris_Robb]

Re: Some comments on this response

Ken, some further questions which perplex me.

With a modern alternator, let say producing 14.4V, do they keep the voltages at 14.4 ALL the time they are running, or do they go into float mode (13.8V)?

If they don't then I would rather have an alternator producing a rather lower voltage, like mine (13.8) and add a Sterling controller, that will allow the voltages to drop off once charging is finished.

I take it that provided the natural output of the alternator is below that of the Sterling Float stage volatge, then the Sterling will keep it at this (the Sterling) float voltage.

ALSO

If the modern alternator only produces 14.4V then surely this will not charge the batteries as agressively as one charging at 14.8V (allbeit there will be substantial water loss). Perhaps this is because a "sealed" battery will loose its water and be permenantly damaged if charged at this rate?

One thing I did find when I fitted the Sterling, is that it is extremely intollerent of substandard cabling, enev if on the face of it it all looks ok. We continually had "over voltage" checks when the battery volts reached 14.5V from the sterling, which disabled the sterling. This was solved by doubling up the positive and negative cables, adding to the standard ones fitted by Westerly. this instantly solved the problem, (as Charles Sterling said it would!!) and increased the amount of amps on start of charging from 35 to 45, which was a significant improvement.

 

[Ken_Irby]

Well, it was me who wrote it actually on my partner\'s Kentrina\'s login

"With a modern alternator, let say producing 14.4V, do they keep the voltages at 14.4 ALL the time they are running, or do they go into float mode (13.8V)? " with a standard controller there is no sort of stepped two stage regulation as your comment seems to suggest. once the battery is up to the maximum voltage attainable, equilibrium is acheved and maintained. the sterling does this by software control. the sterling will maintain a float voltage of around 14.4 once battery capacity is reached. "If the modern alternator only produces 14.4V then ..." sterling does not recommend sealed batteries for this and other reasons, preferring fully vented flooded ones. yes they will use water. ours lasted eight years with no problems until finally they, one by one over a month's interval, each suffered a "hot" cell. due to varying exchange rates we got a good deal on two and not so good on the other two.
Last paragraph - yes the fatter the conductors and sounder the connections (soldered pref) the better.
Chas on Kentrina's handle