Questions About Operating PowerMax AC to DC Converter

Updated 07/28/2026 | Published 07/23/2026

Products Featured in This Question

PowerMax AC to DC Converter w/ Built-In 3-2-1 Stage Battery Charger - 12V - 45 Amps

(10)

$155.00

Question:

I purchased a 45 Amp converter for my trailer. It came with no instructions, and I have no idea what position the place the three position switch in for proper charging.

asked by: Wayne E

Expert Reply:

Apologies Wayne and thanks for reaching you!

The three position switch on the PowerMax # PM34VR selects the charging mode:

3-Stage – Recommended for most RV owners. This is the factory setting and automatically switches between bulk, absorption, and float charging to keep your battery charged and maintained.

2-Stage – Uses bulk and float charging only. This mode is typically used for specific charging applications where a simpler charging profile is desired.
Fixed Voltage – Maintains a user selected constant output voltage (adjustable from 13V to 16V). This mode is generally used for powering 12V equipment or specialized charging applications rather than everyday battery charging.

For normal RV use, leave the switch in the 3-Stage position. It will automatically manage the charging process and is the best choice for maintaining battery health.

The installation and operating instructions are also linked on this page and the product page under the "Instructions" section if you'd like to download it.

Are you charging a lead-acid battery (flooded, AGM, or gel), or have you upgraded to lithium (LiFePO4)?