Parallax 45RU 45 Amp RV Converter/Charger | 12V DC Power Supply

Parallax 45RU 45 Amp RV Converter/Charger

The RV converter/charger is the heart of your RV’s 12V electrical system when connected to shore power or a generator. It converts 120V AC to 12V DC to power all your 12V appliances, lights, and electronics, while simultaneously charging your RV batteries. A failing converter can cause dim lights, dead batteries, or complete 12V system failure.

This Parallax 45RU 45-amp converter/charger is designed as a direct replacement for Parallax 4400, 4500, and 6300 series converter/chargers. It features 3-stage smart charging, built-in fan cooling, and comprehensive protection circuitry.

Compatibility

• Parallax 4445, 4455, 4465 converter/chargers
• Parallax 4545, 4555, 4565 series
• Parallax 6345, 6355, 6365 series
• Parallax 7145, 7155, 7165 series
• Most 30-50 amp RV converter/chargers with similar footprint
• Compatible with lead-acid, AGM, and gel cell batteries

Specifications

3-Stage Smart Charging

1. Bulk Stage: Maximum current (45A) at 14.8V to quickly recharge deeply discharged batteries. This stage runs until the battery reaches ~80% capacity.
2. Absorption Stage: Voltage held at 14.4V while current gradually decreases as the battery reaches full charge. This stage prevents overcharging while topping off the remaining 20%.
3. Float Stage: Voltage reduced to 13.6V for long-term maintenance. This stage keeps the battery fully charged without overcharging, ideal for extended shore power stays.

Installation Guide

1. Safety first: Disconnect 12V battery (negative terminal first). Unplug 120V shore power. Turn off the main 12V disconnect switch if equipped.
2. Access the converter: Locate the converter/charger, typically mounted in a cabinet or near the electrical panel. Remove any access panels.
3. Document connections: Take photos of all wiring connections before disconnecting. Label wires if needed.
4. Disconnect 120V AC: Remove the 120V AC input wires (black = hot, white = neutral, green = ground) from the converter. Use wire nuts to cap the exposed ends.
5. Disconnect 12V DC: Remove the 12V DC output wires (red = positive, white = negative) from the converter.
6. Remove old converter: Unscrew the mounting screws (typically 4-6 screws) holding the converter to the mounting bracket or wall.
7. Install new converter: Mount the new Parallax 45RU in the same position. Secure with mounting screws.
8. Reconnect 12V DC: Connect positive (red) and negative (white) wires to the corresponding terminals. Ensure tight connections.
9. Reconnect 120V AC: Connect hot (black), neutral (white), and ground (green) wires to the corresponding terminals. Use wire nuts or terminal blocks.
10. Test operation: Reconnect 12V battery. Plug in 120V shore power. Verify the converter powers on (fan may run). Measure 12V output with a multimeter — should read 13.6-14.8V depending on charging stage. Check all 12V appliances for proper operation.

Common Symptoms of a Bad Converter/Charger

• 12V lights dim or flicker when on shore power
• Batteries not charging — voltage stays below 12.6V
• No 12V power at all when on shore power
• Converter fan runs constantly or doesn’t run at all
• Burning smell or overheating converter
• Tripped circuit breaker on the 120V circuit
• Batteries go dead quickly even when plugged in
• Voltage fluctuates between 11V and 15V (unregulated output)

Frequently Asked Questions

Q: How do I test if my converter is working?

A: With shore power connected, measure the voltage at the 12V output terminals or at the battery. A working converter should read 13.6-14.8V (depending on charging stage). If the voltage reads the same as the battery voltage (12.2-12.6V) and doesn’t increase when shore power is connected, the converter is not charging. Also check that the 120V circuit breaker is not tripped.

Q: Can I upgrade from a 30A converter to this 45A model?

A: Yes, as long as your 120V AC circuit can handle the additional load. A 45A converter draws approximately 6-8A at 120V AC under full load. Most RV 120V circuits for converters are rated for 15-20A, so this should be fine. Also ensure your battery cables are sized appropriately (minimum 6 AWG for 45A).

Q: Is this converter compatible with lithium batteries?

A: This converter is designed for lead-acid, AGM, and gel cell batteries with the standard 3-stage charging profile (14.8V bulk, 14.4V absorption, 13.6V float). Lithium (LiFePO4) batteries typically require a different charging profile (14.6V constant voltage, no float stage). If you have lithium batteries, contact us for a lithium-compatible converter option.

Q: How long does a converter/charger last?

A: A quality RV converter/charger typically lasts 8-15 years with normal use. Factors that shorten lifespan include: excessive heat (poor ventilation), overloading (running too many 12V appliances), voltage spikes, and moisture. Regular cleaning of the fan and heat sink can extend the life of your converter.

Related Products

• 628661 Refrigerator Power Board — Dometic & Norcold refrigerator control board
• LP Propane Gas Regulator — 2-stage automatic propane regulator for RVs
• RV Water Pump 12/24V — 12V/24V RV water pressure pump

Need help choosing the right converter/charger for your RV? Contact our technical team with your current model and battery setup. Free shipping and duties included on all orders.