Charging and power generation

Boat alternators.High-output alternators and external regulators.

with an external regulator closes this gap.

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Boat alternators: high-output alternators and external regulators
  • 250 ACharging current of the largest XT alternator
  • 12 and 24 Vfor both system voltages
  • Volvo and Yanmarmatching versions

Why the standard alternator is often not enough

Standard alternators are built for the starter battery and the engine's base load. Their internal regulator charges at a fixed voltage that cuts back too early for a full battery bank. In addition, they get hot under continuous load and then deliver considerably less than the rated current on the label. With many consumers on board and few engine hours, the batteries never get fully charged.

Why the standard alternator is often not enough

What a high-output alternator does differently

  • More current even at low rpm: the machines are built for high continuous current, not just a short peak.
  • External regulator with charging profile: multi-stage charging with the right profile for AGM, gel or lithium instead of one fixed voltage.
  • Temperature sensors: the regulator measures alternator and battery and reduces output before things get too hot.
What a high-output alternator does differently

Sizing correctly

The output must match three things: the battery bank that takes the current, the belt drive that transmits it and the cable cross-section between alternator and battery. From about 100 A the belt drive should be checked, as a simple V-belt does not transmit this power reliably. Matching alternators and pulley kits from Balmar are available for many Volvo and Yanmar engines. The alternator calculator suggests model, regulator and belt, and the cable configurator calculates the cross-section.

Sizing correctly

Alternator and lithium battery

A lithium battery can disconnect itself from the network via its BMS. If the alternator is under load at that moment, a load dump occurs that can damage the rectifier. The remedy is either an external regulator that evaluates the BMS charge enable signal or a DC-DC charger between starter and house battery.

Alternator and lithium battery

Matching products.From our range.

View all ›
Alternator, XT series, 170A, 12V, double base 3.15″ Alternator, XT series, 170A, 12V, double base 3.15″1.166,00 €View › Alternator, XT series, 250A, 12V, single foot 1-2" Alternator, XT series, 250A, 12V, single foot 1-2"1.431,00 €View › Alternator, XT series, 90A, 24V, double foot 3.15" Alternator, XT series, 90A, 24V, double foot 3.15" 1.219,00 €View › Alternator Regulator Alpha Pro III Alternator Regulator Alpha Pro III394,01 €View › Alternator Regulator 12V MC 618 Alternator Regulator 12V MC 618428,00 €View › Alternator Regulator 24V MC 624 Alternator Regulator 24V MC 624504,00 €View › Alternator equalizer CFII Alternator equalizer CFII289,20 €View › Alternator Belt Tensioner Belt Buddy Alternator Belt Tensioner Belt Buddy65,30 €View ›

Categories.The full range.

Frequently asked questions.Short answers.

Do I need an external regulator with a high-output alternator?

Yes. Only the external regulator charges with a multi-stage profile and monitors the temperature of alternator and battery. Without it, you lose most of the benefit.

From what output do I need to check the belt drive?

From about 100 A charging current. Above that, a simple V-belt slips or wears quickly. A pulley kit with a flat or serpentine belt and a suitable tensioner solves this.

Can I connect an alternator directly to a lithium battery?

Only with load dump protection. You need a regulator that evaluates the BMS charge enable signal, or a DC-DC charger between starter and house battery.

What does a balancing regulator do with two engines?

It balances the output of two alternators charging the same battery bank so that one machine does not do all the work and overheat.

Read more.In the philippi Academy.

Load and Power GenerationUpgrade to High-Output AlternatorsA larger alternator alone is useless if the belt drive or engine power cannot keep up. The conversion...Load and Power GenerationCharge Converters, Boosters, or Isolation Relays: What Fits WhenThree methods that have the same goal yet differ fundamentally. When a split-charge relay suffices, when a battery-to-battery...Battery and StorageUpgrading from AGM to lithium: What else needs to be replacedChecklist from the charge controller to the main fuse, in the order of procedure — including capacity calculation,...Battery and StorageSeparating Starter and Leisure Batteries: Methods ComparedIsolation diodes, isolation relays and charge converters compared — including voltage drop, switching thresholds and the question of...

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