Theory and History of Alternators and Regulators

[ndutton]

Yet the problem as it has been stated remains, how do we know when the battery is full? A prolonged cranking in a car will discharge a battery just as well as any load on a boat. The battery gets discharged, it gets recharged. How do we know when the car battery is full? It really is the same question.

The point I'm raising is many get all verklempt on their boat and never give it a second thought in their car. Why? Because we trust the car's charging system to do its job without additional user input.

[joe_db]

Yet the problem as it has been stated remains, how do we know when the battery is full? A prolonged cranking in a car will discharge a battery just as well as any load on a boat. The battery gets discharged, it gets recharged. How do we know when the car battery is full? It really is the same question.

The point I'm raising is many get all verklempt on their boat and never give it a second thought in their car. Why? Because we trust the car's charging system to do its job without additional user input.

A car is nothing like a sailboat. A starter might draw between 100 and 200 amps. One minute would be a LOT of cranking for a car, my cars all start in about 5 seconds. Ignoring Peukert's Constant that is like 1 amp hour and with it probably around 5. Unless something is really wrong with your car it is going to be using just a few percent of its capacity to start the car. Cars use thin plate batteries designed to get the most possible cranking out in a short burst, even when very cold. The thin plate batteries then recharge very quickly when the car is running. If you ever try and cycle car batteries to 50% or 80% discharge, you will get very few cycles out of them before they are ruined forever. You can't even get graphs of depth-of-discharge vs. expected cycle life because start batteries do not get tested that way and the number would be depressingly low if they were tested.

[ndutton]

Discharge → charge.
The problem as stated is not the rate of discharge, it's knowing when the battery is fully charged regardless of its discharge profile. I'm not the one who stated the problem in those terms. In fact, I don't think there is a problem which leads us to what exactly is being solved here which in turn leads us to answer the question of what is the goal?

[Dave Neptune]

Your battery type, it's condition, the integrity of the connections and the integrity of the "sensors" connections control your system. In most of the cases we see here the connections and battery neatness are sometimes abominable at best in these old boats.

You the operator, the batteries, the quality of connections and the charging system need to work in harmony. The battery of any kind is limited to it's input and output rates so choice comes to play. then matching the charging to your needs from the power available.

I have seen to often a boat with horrible electrical conditions have the owner throw wads of money at with "new monitoring" systems only to screw things up worse because the problem was the wiring. Don't waste money there unless you upgrade the whole "package".

I have gone to solar for my needs and the eng/alt is there only for running the boat under power. Once shut down the only power I am interested in is the "house bank" usage. So I brought the solar power directly to the power supply at the panel. The solar regulator works well with the alt when both are working. If I turn on the LP switch my input goes up an amp and visa versa. I am at float by 10AM and if the "acceptance" is at 5 amps and I turn on a light the amps out will increase and the solar regulator will add whatever is needed. The system will go to trickle after noon unless the refrigeration is on.

Dave Neptune

[joe_db]

Now on to what you can get today in 2020.
I am totally leaving off a CANBUS integrated lithium battery system that can do everything and costs more than my boat, we'll stick to things vaguely possible at least for less than the cost of the boat it goes in

Alternators: A4s use 2 inch single foot mounts. 1 inch single foot mounts can work with an adapter.
Our stock alternators were either 35 or 50 amp Motorola alternators. They were OK for the time, but the 13.8 volt setpoint all the ones I have or had is too low. They are easy to modify for external regulation.
Balmar makes a few alternators that fit the A4. The one I have is a Balmarized variant of the 50 amp Motorola. They all are very nice looking and are set up for external regulators. Note that is not just a white painted Motorola! Besides for the external regulation it puts out more amperage. Not a huge amount more, but I can see the difference.

You can see they had a common origin, but they are not identical. Looking on FleaBay is your best bet, these things are not worth anything close to the list price when an A4 will never exceed 50 something amps out of ANY alternator on the stock mount and pulley.

The other major source of A4 alternators is the endless variants of the Delco 10si alternators. These are made in marinized and non-marinized versions, single wire and three wire, and outputs from about 50 amps to 150. Many of them are strictly Chinese knock-offs with no actual AC-Delco parts whatsoever. They all have internal regulation. They are somewhat of a pain to make externally regulated. On the plus side there are endless varieties of 10si regulators around at various setpoints, so if you are sticking to a fixed setpoint setup you can probably find a regulator close to what you want. Prices range from $60 to the hundreds of dollars. I would hope the higher prices = better quality, the cheap 10si I had lasted maybe 50 hours.
Here is one sold by our host towards the higher quality end of the spectrum:


Next up - what, if any, regulators to connect to these.

[joe_db]

Modern regulators:
First thing is to learn A circuit vs. B circuit, also known an P field vs. N field.

When you have an "A" circuit type voltage regulator means full power is sent to one brush while the voltage regulator controls the output by varying the ground to the other brush. Also known as N field. The regulator controls the connection to GROUND. This is most, maybe all, 10si variants.

B circuit is the opposite, the field is always grounded at one end and the regulator controls the voltage fed to the field. This is all Balmars and the Motorolas found on A4s. These are by far the easiest to add regulators too or troubleshoot. Also known as P field.

10si internal regulators are numerous and varied. This is just one sample I found: https://store.alternatorparts.com/10si-regulator.aspx All of them are fixed set point, but you can pick numerous voltages.
If you want to change your 10si to external regulation, you can take it apart and hack the internals to provide a connection. That is a bit of a pain but cheap. That is what I did to mine.
This kit changes a 10si to B circuit and provides a simple regulator with a voltage adjustment

https://store.alternatorparts.com/partnod7044.aspx

I have no dealings with that company nor have I tried that regulator, but it looks worthwhile to me, especially if you don't want to invent your own system to change over to external regulation.

Moving away from 10si specific devices, there are several regulators you can source with either one user adjustable setpoint or 3/4 stage regulation. These are designed for pretty much any P field/B circuit alternator and some can adapt to A circuit/N field.
Some basic single voltage regulators. Note none of these are endorsements of any brand or vendor unless I specifically say so.
Here is one that looks quite heavy duty and has a remote pot for adjustments.

https://www.amazon.com/World-Power-Systems-adjustable-regulator/dp/B00OBTZ8OE/ref=sr_1_1?crid=38WET7ONVKFF4&dchild=1&keywords=transpo+regulator&qid=1588349567&sprefix=transpo+regu%2Caps%2C150&sr=8-1

Here is a cheaper one with the adjustment on the regulator itself:

https://www.amazon.com/dp/B07LHCNJ8P/ref=sr_1_2?crid=1EXJS58BAU08N&dchild=1&keywords=v1200+regulator&qid=1588349714&sprefix=v1200+reg%2Caps%2C140&sr=8-2

Balmar sells their own versions of single set point regulators, one set to 14.1 and the other is adjustable. The adjustable one looks a LOT like the V1200, enough so I would probably just get whichever one was cheaper.

http://www.balmar.net/products/single-stage-regulators/

More to follow.

[joe_db]

What modern 3 stage (aka smart) regulators can do:
1. Pretty much all of them can be set for different battery chemistry. Gel, AGM, flooded, and lithium batteries all use different charging regimes. Some even have subtypes, big flooded traction batteries like golf cart batteries can usually charge with higher voltage than car batteries even though both are flooded.
2. They will have a way to switch to the lower float voltage setting. One way is that they sense the field current needed to hold the absorption voltage and when that tapers off, they know the battery is near full and trip over to float. I am sure there are others I am not familiar with and they have various ways of trying to differentiate loads from low batteries. My Balmar, once tripped to float, will go back to bulk/absorption for a short time if it senses a heavy load but then quickly switch back. There are various ways of doing or not doing this.
3. Alternator temperature sensing. Some will use temperature indications from the alternator to back off if it appears the alternator is overheating.
4. Soft start - Some will gradually ramp up the field current to take it easy on belts.
5. Alternator limiting. I haven't seen any low to mid range regulators that actually measure the output directly, but you may have a function to limit field current to a certain percentage of maximum. This sort of does the same thing, less amps but voltage set-points remain the same. My FleaBay sourced regulator had this set and I was going nuts trying to figure out why my charging was so slow
6. Battery temperature sensing. This does TWO things, not one. The more obvious function is backing off charging to not boil the battery, but the other one is changing the voltages to suit battery temperatures. This is actually very important, batteries need more voltage when cold and less when hot.
7. Force to float. Some regulators can be manually forced into float mode.
8. Equalization mode. Some regulators can drive the voltage to 15, 16, or even more volts to equalize batteries. This would usually be manually switched on and off.
9. I think all of them have remote sensing wires so you sense charge voltage at the battery, not at the alternator.
10. Some can do N field/B circuit.
11. Some can do 24 volts with either a switch or auto-sensing.

[joe_db]

The current Balmar lineup:

http://www.balmar.net/multi-stage-regulators/

I like Balmar products. I hate the prices. The only reason I have a Balmar alternator and regulator is from diligent FleaBay searching
This is my regulator:

http://www.balmar.net/?product=regulator-ars-5-h

This is the manual:

http://www.balmar.net/wp-content/uploads/2017/05/PDS-ARS-5-H-1.pdf

Sterling also makes a line of regulators.

https://sterling-power.com/collections/alternator-regulators/products/universal-advanced-digital-alternator-regulator-pro-reg-dw-waterproof

One thing I like about them is they show up on FleaBay for reasonable prices WAY more often then Balmars do.
Use this search string: https://www.ebay.com/sch/26443/i.htm...ling+regulator
Right now there is one for about $150 or so.

[joe_db]

Now you have done all this, one nice thing perhaps not appreciated right away about having access to the field connection is it makes troubleshooting easy. Disconnect the regulator and connect the field to 12 volts and if you get a jump in voltage the regulator is bad and if not the alternator is.
When my old regulator died, I didn't have a spare so I made do with a light bulb:

The higher wattage the bulb, the higher voltage from the alternator