1. CTEK D250S DUAL CTEK SmartPass A revolutionary solution for 12V Dual Battery systems

2. It all started simple….
One Alternator
One Battery
One Starter Motor

3. Then came a fridge, lights, navigation and….
and suddenly the battery was dead.

4. Well, let’s add another battery for all consumers
…and a Black Box to separate
the two battery banks
Diodes
VSR
MOSFET
Relay

5. … and some more stuff 3-step alternator
Solar panel with dedicated regulator
Thick wires
Battery Switch
0 – I – II - Both
…and a Black Box to separate
the two battery banks
Diodes
VSR
MOSFET
Relay
110/230V charger
with multiple outputs
Battery watch

6. … and some more stuff 3-step alternator
Solar panel with dedicated regulator
Thick wires
Battery Switch
0 – I – II - Both
…and a Black Box to separate
the two battery banks
Diodes
VSR
MOSFET
Relay
110/230V charger
with multiple outputs
Battery watch

7. But problems remained with:
3-step alternator
But problems remained with:
Very long recharge time from alternator
Engine idling just for battery charging
Batteries rarely fully charged, which reduced the useful time
Regular battery replacement
Solar panels conflicting with other sources, which reduced output
No charge of starter battery from solar
Overheated service batteries
Costly, difficult to trouble-shoot, expand, modify, … …
Solar panel with dedicated regulator
Thick wires
Battery Switch
0 – I – II - Both
…and a Black Box to separate
the two battery banks
Diodes
VSR
MOSFET
Relay
110/230V charger
with multiple outputs
Battery watch

8. For a motor home have also large load on the starter battery
For a motor home have also large load on the starter battery! This gives rise to voltage drops
14,0V
13,3V
relay
13,0V

9. Charge time 8,5h to 90% charge rate.
Charging at +25°C and 13,8V
145Ah battery, discharge with 75Ah. Max. charge current: 45A
Charge time 8,5h to 90% charge rate.

10. Charge time 2,5h to 90% charge rate.
Charging at +25°C and 14.4V
145Ah battery, discharge with 75Ah. Max. charge current: 45A
Charge time 2,5h to 90% charge rate.

11. Charging at +0°C and 13,8V
145Ah battery, discharge with 75Ah. Max. charge current: 45A

12. Let’s start with the basics again
One alternator
Let’s start with the basics again
… and a CTEK D250S DUAL that separates the two battery banks
Connect the alternator directly to the Starter
..add another battery bank

13. Engine off The Starter battery is prepared for engine start
…and the Service batteries serve consumers

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

15. Attach a solar panel directly
Synchronized with the alternator when the engine is running

16. The panel serves both batteries when the engine is off
…and charging of Service battery with built-in Maximum Power Point Tracker (MPPT)
Pulse maintenance of Starter battery
Maximum Power Point

17. CHARGING PROGRAM D250S DUAL
The charger starts charging the target battery when the supply voltage exceeds 13.1V for 5 sec (engine on).
The charger stops charging the target battery when the supply voltage drops below 12.8V for 10 sec (engine off).
STEP 1 desulphation
Detects sulphated batteries. Pulsing current and voltage, removes sulphate from the lead plates of
the battery restoring battery capacity.
STEP 2 bulk
Charging with maximum current until approximately 80% battery capacity.
STEP 3 absorption
Charging with declining current to maximize up to 100% battery capacity.
STEP 4 float
Maintaining the battery voltage at maximum level by providing a constant voltage charge.
STEP 5 pulse
Maintaining the battery at 95–100% capacity. The charger monitors the battery voltage and gives
a pulse when necessary to keep the battery fully charged.

18. LIMITATIONS: 20A max from D250S DUAL
Charge current shared with consumers, which prolongs charge time

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

20. D250S DUAL limitations Max 20A
Directly from alternator:
High current initially (up to 30 minutes)
Current tapers off to very low level – 100% charge from alternator almost impossible
Charge Current
Charge Current

21. D250S DUAL limitations Max 20A
Direct charging from alternator could be faster during a short time for:
Large alternator
Large Service Battery bank
Deep discharged batteries
Charge Current
D250S DUAL is faster in the long run, but could be behind during the first minutes.
20Amps
Charge Current

22. D250S DUAL limitations Charge current shared with consumers
Current used for consumers…
…prolongs charge time

23. SOLUTION – and more! CTEK SmartPass
High charge currents through SmartPass

24. SOLUTION – and more! CTEK SmartPass
Low charge current through D250S DUAL.

25. SOLUTION – and more! CTEK SmartPass
Green curve => minimized charge time

26. SOLUTION – and more! CTEK SmartPass
Almost all current through D250S DUAL is used for charging.
Critical consumers directly from battery
Charge
Consume
Move non-critical consumers. SmartPass provide current direct from Alternator.

27. Built-in Battery Watch
SOLUTION – and more!
Built-in Battery Watch
Consume
Engine off. Current from the Service Battery

28. Built-in Battery Watch
SOLUTION – and more!
Built-in Battery Watch
Service battery and critical items are protected.
Engine off. Service battery deep discharged. Disconnect non-critical items.

29. Solar Panel serves all batteries!
SOLUTION – and more!
Solar Panel serves all batteries!
Solar panel charges Service battery and maintains Starter battery
Charge
Maintain
Charge

30. Overheat protection of Service battery
SOLUTION – and more!
Overheat protection of Service battery
Service battery overheated due to age, oversized alternator, high ambient temperature.
Charge
60°

31. Overheat protection of Service battery
SOLUTION – and more!
Overheat protection of Service battery
SmartPass disconnects direct path from alternator. D250S Dual finalize charge with reduced voltage and current
Charge
55°

32. 110/230V charger serve both battery banks with one output
SOLUTION – and more!
110/230V charger serve both battery banks with one output
Charge
Charge
Charge
AC/DC charger charges both Service and Starter battery

33. CTEK D250S DUAL & SmartPass
The Dynamic Duo B
Five connection points for a DC system at a completely new level of standard! C A D E

34. Basic Electricity Onboard
STORE
PRODUCERS
USE LATER
USE DIRECT
CONSUMERS

35. Smartpass - The DC Manager
STORE
USE DIRECT
USE LATER
PRODUCERS
CONSUMERS