Alternator regulator 3YM30

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anniebray

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My boat had a new Yanmar 3YM30 fitted last year (well it was also a new boat !) The alternator is the standard 60A. I was quite keen to have a smart regulator fitted at the time but it would have invalidated the engine warranty & the yacht builders were insistant that "the latest alternators have such good performance that additions are not necessary". I was sceptical about this at the time so my first question would be to ask if this is true. I would like to optimise my battery charging so am wondering how much benefit I would get by fitting a smart regulator controller (say Sterling) bearing in mind that my house batteries are 3x 105AH maintenance free ( bad choice I think !) which restricts maximum charging to 14.5v.
 
See www.smartgauge.co.uk then click on "Technical Info".---then "Alternator Regs".
I changed my mind about a fancy regulator after reading. I checked voltage across battery terminals and found 14.4v, even at tickover [3 yr. old Beta].
I have standard lead acid batteries, which would take the "boost" of 14.8ish volts, but at the cost of excess gassing.
If you can only accept 14.5v, any gain in performance will be very marginal.
 
Re "Smartguage", looks to be a most informative site & already I begin to believe that my yachtbuilder did know what he was talking about. I noticed also "Peukerts Equation" which features in the instructions with my battery monitor DCM600 which is presently performing in a most peculiar manner. eg with batteries on charge for days, capacity is indicated to be falling but once the engine is started & we are underway capacity jumps to 100%. I shall have to check connections & also the input set up data which includes this mysterious Peukert.
Thanks for the info!
 
Very good site www.smartguage.co.uk , well laid out and lots of useful information well explained in stages to avoid brain overload! thanks to Varne and Steve 28.I have also used the www.sterling-power.com website to help clear up the many misconceptions which beset us all! Good wintering to all esp those in the freezing bits of territory
 
If you (AnnieBray) use your battery monitor carefully you will be able to monitor what the regulator that you have is doing.
Voltage should stay high on start up especially if batteries are a bit low. The voltage should fall after the batteries are charged.
Similarly the current into the batteries should start high and remain high until the batteries are charged then reduce in a step.
It is this ability to maintain a high charge current until the batteries are charged that indicates a "smart " charge regulator.
A standard regulator will charge at a constant voltage and so as the batteries take some charge the current will fall steadily. Which means the last part of the charge will take forever. ie to get a full charge takes forever of engine running wheras a smart charger controller will increase the voltage to force more current in until charge is near full hence shorter engine running time required for full charge.

It is this engine running time that is why people want a smart charge controller. A standard (old fashioned) regulator will eventually do the job. As in your car so if you do a lot of motoring old one will be fine. But if you run the engine just to charge the batteries then a smart one will mean less running time. olewill
 
Turns out that my Yanmar Alternator is regulated to 14.4v. In addition I have BEP voltage sensitive relay for split charging so no volt drop. According to the Smartgauge web site & bearing in mind that I have sealed lead acid batteries, I would get no benefit from fitting a smart regulator.
Thanks for all contributions.
 
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