For Mainesail

[sailaway78]

Hey Mainesail,
On ScottB's post about alternator sizing, you had a short video showing the actual amp draw starting, and the quick decrease in amps accepted from the alternator, once the engine is running. If I am not mistaken you run an internal regulator. Does this video show the amperage being accepted into the batteries with an internal regulator or an exteranl three stage. Inquiring minds want to know.

 

[Maine Sail]

Hey Mainesail,
On ScottB's post about alternator sizing, you had a short video showing the actual amp draw starting, and the quick decrease in amps accepted from the alternator, once the engine is running. If I am not mistaken you run an internal regulator. Does this video show the amperage being accepted into the batteries with an internal regulator or an exteranl three stage. Inquiring minds want to know.

That is a "dumb" regulator but it still senses the state of charge and adjusts in accordance with the state of charge based on acceptance. I currently don't use a "smart" regulator but have owned them in the past. I have also had three failures of Balmar's two ARS-4's and one ARS 5..

 

[sailaway78]

What I thought

I don't think the Balmars are worth the cost. Maybe it they were super dependable, but I just can't see the expenditure for something that doesn't have a stellar reputation.

 

[Bill Roosa]

That's an easy one

Hi Nice-N-Easy
Batteries act just like variable resistors when charging and many of the things you see when discharging also occur during charge.
To fully understand this you need to understand the concept of internal resistance in a battery. The perfect battery would have zero internal resistance and be able to provide 100% of the AH you pumped into it. Alas, we live in a part of the universe where that does not happen.
A battery has low internal resistance when deeply discharged so it accepts lots of current and does not heat up much. As the amount of charge stored increases the resistance goes up and therefore so does the voltage required to maintain a give amp input and heat generated. At full charge, the battery has an internal resistance that will not allow more than a trickle of charge at normal system voltages.
The spike you see in amps when the alternator comes on line with a fully charged battery is just the change from "surface charging" to regular charging. Surface charging is exactly the same as the surface charge that you can get when you discharge the battery after letting is sit for a while without a load. If you turn the alternator on and then let the amps stabilize and turn the alternator off and right back on you do not get the spike a second time. You have to wait (just like surface charge) till the electrolite equalizes again and battery internal resistance drops a bit.