(9) Establishing Correct Voltage Regulation

What is the consequence of incorrect voltage regulation in DC systems?

Nothing will work correctly in a DC system.

What happens when a battery starts absorbing charging current?

It creates a voltage differential between the plates.

What happens when a battery plate starts getting full?

The voltage differential causes electrolyte to migrate deeper into the battery and onto next set of plates, since it starts looking for easier space to fill.

How does the voltage regulator work in the charging device?

The regulator has a set point that, when reached, turns off the device to allow for migration of electrolyte through the plates due to voltage differential. Once that set voltage gets below the set level, the device turns back on and repeats the cycle.

What occurs to the charge acceptance rate as a battery charges?

It slows down as the voltage differential decreases.

What happens when a large charging device is used on a small battery?

It quickly drives up the surface voltage, causing the regulator to cut back charging output, leading to wasted charging capacity.

What is the consequence of charging a small battery too quickly?

The electrolyte does not have enough time to diffuse to the inner plates, which can lead to the battery appearing fully charged but actually being well discharged.

What occurs when a small charging device is connected to a large battery bank?

The charging output may keep up with diffusion, preventing the regulator from turning off the device, potentially causing overheating and premature failure.

What is the Bulk phase in battery charging?

The phase when a well-discharge battery accepts most charge and full alternator output.

What happens during the Absorption phase of battery charging?

As the battery charges, the charge acceptance rate decreases, causing the alternator to turn on and off for longer periods (still hundreds of times a second)

What is the impact of raising the voltage regulator set point during charging?

It accelerates the rate of current diffusion into the interior plates and reduces charge time, but if set too high, it can overheat the plates and cause electrolyte breakdown.

What happens to the plates if the regulator set point is too high?

The plates will overheat and buckle, leading to electrolyte breakdown and drying out.

What is the primary purpose of a voltage regulator in charging systems?

To maintain optimal voltage settings during battery charging.

What happens to cranking batteries under load?

Their regulator settings remain low because they only take a little load.

What can happen if the regulation is too high for Deep Cycle batteries during extended engine run time?

The batteries can get overcharged.

What are the three phases followed by multistep regulators?

Bulk, absorption, and float

What should the charging current from a multistep regulator equal?

The DC load while the engine is running, plus 10% to 100% of the battery's rated Ah capacity.

At what maximum temperature should battery regulators operate to prevent thermal runaway?

125°F.

What precaution should regulators include to monitor battery temperature?

Temperature sensing.

Why do most regulators have a time delay that slowly ramps up output?

To avois shock loading the drive belt when cranking, which could cause it to snap or slip.

What is a disadvantage of using automotive or high output alternators for charging batteries?

It can take up to 7 hours to fully charge, often leading to impractical charging times.

What are the benefits of using a multistep regulator and high output alternator?

It can cut charge time in half, improve DC performance, extend battery life, lower costs, and reduce electrical issues.