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CTEK D250S DUAL CTEK SmartPass

A revolutionary solution for 12V Dual Battery systems

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It all started simple….

One AlternatorOne Battery

One Starter Motor

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Then came a fridge, lights, navigation and….

and suddenly the battery was dead.

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Well, let’s add another battery for all consumers

…and a Black Box to separate the two battery banks

DiodesVSR

MOSFETRelay

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… and some more stuff

…and a Black Box to separate the two battery banks

DiodesVSR

MOSFETRelay

3-step alternator

Battery watch

110/230V chargerwith multiple outputs

Solar panel with dedicated regulator

Thick wires

Battery Switch0 – I – II - Both

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… and some more stuff

…and a Black Box to separate the two battery banks

DiodesVSR

MOSFETRelay

3-step alternator

Battery watch

110/230V chargerwith multiple outputs

Solar panel with dedicated regulator

Thick wires

Battery Switch0 – I – II - Both

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…and a Black Box to separate the two battery banks

DiodesVSR

MOSFETRelay

3-step alternator

Battery watch

110/230V chargerwith multiple outputs

Solar panel with dedicated regulator

Thick wires

Battery Switch0 – I – II - Both

But problems remained with:Very long recharge time from alternatorEngine idling just for battery chargingBatteries rarely fully charged, which reduced the useful timeRegular battery replacementSolar panels conflicting with other sources, which reduced outputNo charge of starter battery from solarOverheated service batteries Costly, difficult to trouble-shoot, expand, modify, ……

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arge

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timmar

Charge acceptance at +25°C and 13.8V

145 Ah battery, discharge with 75Ah. Max charge current 45A.

8.5h to recover 90%.

… and the need for temperature compensationC

urr

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Time [h]

Source: Exide Scandinavia

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(%)2.5h to recover 90%.

Charge acceptance at +25°C and 14.4V

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Time [h]

Source: Exide Scandinavia

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Charge acceptance at 0°C and 13.8V

Source: Exide Scandinavia

24h is not enough to recover 90%.

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Let’s start with the basics again

One alternator

..add another battery bank

Connect the alternator directly to the Starter

… and a CTEK D250S DUAL that separates the two battery banks

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Engine off

The Starter battery is prepared for engine start

…and the Service batteries serve consumers

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Engine running

CTEK D250S DUAL charges the Service batteries with a temperature compensated charging. • High temp => lower voltage• Low temp => higher voltage

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Temperature [C]

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arg

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olta

ge

[V

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14.4V @25°C

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Attach a solar panel directly

Synchronized with the alternator when the engine is running

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The panel serves both batteries when the engine is off

Pulse maintenance of Starter battery

…and charging of Service battery with built-in Maximum Power Point Tracker (MPPT)

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Cur

rent

[Am

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CURRENT [Amps]

POWER [Watt]

VOLTAGE [Volt]

POWER = VOLTAGE x CURRENT

Maximum Power Point

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LIMITATIONS:20A max from D250S DUAL

Charge current shared with consumers, which prolongs charge time

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Cha

rge

Cur

rent

Charge Current

D250S DUAL limitationsMax 20A

D250S DUAL charges with 20A until the battery reaches max voltage. The current then tapers off to a fully charged battery

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D250S DUAL limitations Max 20A

Cha

rge

Cur

rent

Charge Current

Directly from alternator: • High current initially (up to 30 minutes)• Current tapers off to very low level –

100% charge from alternator almost impossible

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D250S DUAL limitations Max 20A

Cha

rge

Cur

rent

Charge Current

Direct charging from alternator could be faster during a short time for:• Large alternator• Large Service Battery bank• Deep discharged batteries D250S DUAL is faster in the

long run, but could be behind during the first minutes.

20Amps

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Cha

rge

Cur

rent

Charge Current

D250S DUAL limitationsCharge current shared with consumers

…prolongs charge time

Current used for consumers…

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SOLUTION – and more!CTEK SmartPass

High charge currents through SmartPass

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SOLUTION – and more!CTEK SmartPass

Low charge current through D250S DUAL.

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SOLUTION – and more!CTEK SmartPass

Green curve => minimized charge time

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SOLUTION – and more!CTEK SmartPass

Charge

Consume

Move non-critical consumers. SmartPass provide current direct from Alternator.

Almost all current through D250S DUAL is used for charging.

Critical consumers directly from battery

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SOLUTION – and more!Built-in Battery Watch

Consum

e

Engine off. Current from the Service Battery

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SOLUTION – and more!Built-in Battery Watch

Engine off. Service battery deep discharged. Disconnect non-critical items.

Service battery and critical items are protected.

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SOLUTION – and more!Solar Panel serves all batteries!

Charge

Charge

Solar panel charges Service battery and maintains Starter battery

Maintain

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SOLUTION – and more!Overheat protection of Service battery

Charge

Service battery overheated due to age, oversized alternator, high ambient temperature.

60°

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SOLUTION – and more!Overheat protection of Service battery

Charge

SmartPass disconnects direct path from alternator. D250S Dual finalize charge with reduced voltage and current

55°

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SOLUTION – and more!110/230V charger serve both battery banks with one output

Charge

Charge

AC/DC charger charges both Service and Starter battery

Charge

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CTEK D250S DUAL & SmartPassThe Dynamic Duo

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B

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Five connection points for a DC system at a completely new level of standard!