Alternator charge controller ?

The solar panel on my boat is connected to the starter battery with a (MPPT) charge controller, so the battery gets the optimum charge voltage/current.

I doubt if my outboard Suzuki DF115A also has a charge controller, and that the power from the alternator is delivered (via rectifier) straight to the battery, so voltage/current varying with RPMs only.

Would it make sense to add a chargecontroller to my outboard (if these exist)??

THANKS,
V.

 

alternator already has. that's what makes it an alternator not a generator

 

The alternator has a voltage regulator which is not the same as a charge controller. However, the difference is whether the controller is simply outputting a constant voltage or adjusting charging rate depending on battery condition.

 

The alternator regulator meets the needs of a traditional lead acid battery systems.
One imagines it could be updated to meet The needs of a modern battery technology, if needed.

Do we know what @Vronsky battery technology happens to be? I assumed Lead acid, because he was charging direct from alternator. I did not think you could do that with lithium, or any of the more exotic ones.

 

You can charge any type of battery from an alternator. Li-Ion batteries are more forgiving than flooded lead/acid. AGM are in between and take a faster charge than the old lead/acid typed. Alternators with only a voltage regulator work fine for starting batteries, but are not optimized for house batteries that get discharged to less than 10V. It would not be too hard to add a "smart charge controller" to an alternator.

 

Fully programable alternator regulators do exist, for example here Wakespeed Products http://wakespeed.com/products.html It's for the owner to decide if it makes sense for his particular application.

 

Yes, simple lead acid: no other allowed by the Zuke manual.
Does the alternator also do this 3-stage charging that modern 'smart' battery chargers offer, like the MPPT controller ??

 

I'm not so sure it's that simple: my outboard does not have seperate cables coming from the alternator. The battery is charged with the same cable that also powers the starter motor on the engine. As I understand it, when starting the power goes from the battery to the motor, and when the motor is running the power goes from the motor (alernator) to the battery.
How would a charge controller be added in this situation ?

 

You would have to disconnect the alternator from the voltage regulator and install a charge controller instead. If there is not enough space under the cowling, it can be installed somewhere as close as possible.

 

No, you have a simple one stage internal (meaning it's bolted to the alternator) regulator. This is well proven technology, every car and motorcycle you see has the same thing, no need to panic. "Smart" regulators are only needed for big house banks, the starter battery is ok with your existing setup. After all you would not come to the ideea to change the voltage regulator in your car, just because the manufacturer installed a "dumb" regulator.

 

That's what I was thinking. He could just bypass the regulator and install a "smart" one and run a separate dedicated alternator cable. The bigger question that comes to my mind is why are we doing this? Typically people install aftermarket regulators/charge controllers in inboard engines in order to get house banks properly charged (deep cycle). I don't see outboards being used for this purpose as they are typically day boats but maybe the OP is using his boat differently.

I was curious and did see some specific outboard charge controllers made for the sailboat crowd. These were made for small outboards, kickers, the 9.9's. I couldn't find anything for the larger engines.

 

Actually, I do have a second, service battery on board as well. This one is charged with a Xantrex Echo charger, so not 'combined' with the starter battery.
The motor/alternator and the MPPT controller are both connected to the starter battery, and the Xantrex Echo charger keeps the service battery topped of.

The MPPT technology is very common these days, so I wondered why the -recent- motor/alternator apparently doesn't have this as well, better for the power management I'd say.
Do modern cars really still have old-school alternator/regulator chargers, given the very advanced electronics modern they carry these days ?

 

Yes, modern cars still have one stage regulators, but they are not "old school" they are electronic, and most have temperature compensation. In fact your alternator on the outboard is probably just a standard car alternator from Denso, Bosch, etc.

The setup with the Xantrex charghing the house battery is odd, usually you would have it the other way around, but truth be told, if you have the 40A alternator it does not make any difference whatsoever, and I presume it's more important to you to have a charged start battery, so having the solar on it makes sense.

 

Vehicle type/style alternators as usually wired are quite poor at charging depleted house batteries.
In your car you start the engine, (which typically uses less watt-hours than the capacity of an AA battery,) and that small discharge is restored quickly.
The internal regulators are not "set up" for high rate "bulk charging" of deep-cycle batteries, they are for picking up the small loads as they occur, heater fan/headlights, etc.
When you combine the house and starting batteries for charging, the alternator will typically "see" the higher voltage of the starting batt, and so its regulator cuts back its output,, the result is that the house batt takes an inordinate amount of time to charge.
External devices can be used to couple starting/house batteries together so that each receives its "share" of the power.
Even so, because of the differences between the internal composition of "starting" vs "deep cycle" batts, neither one of them are charged or floated at optimum levels.
It's kind of a "make your choice/take your chance" scenario,, and replace batteries at more or less regular intervals.

 

Correct! I don't like the hassle of shore power, so the solar panel + the Xantrex make sure both batteries are always topped of, without the drawbacks of battery combiners.