Recommended Lithium Compatible Replacement For A Parallax Power Supply 7155

Updated 07/09/2026 | Published 07/23/2022

Question:

I have a Parallax Power Supply 7155 converter in my RV. I want to convert to a lithium battery system. Do you have a in converter that will handle lithium charging profile?

asked by: William G

Expert Reply:

Since there isn't a converter cross section replacement that's compatible with lithium for your Parallax Power Supply 7155 I recommend replacing it with the Progressive Dynamics Mighty Mini AC/DC Panel and Converter/Smart Charger - 60 Amp # PD4060K.

This power center has an LA/LI switch in the upper left-hand corner of the unit that will let you switch the charging profile from Lead Acid (LA) to Lithium (LI).

expert reply by: Kevin C

PD4060K LI-LA Switch
(click to enlarge)

Joshua

7/9/2026

I'm in a similar position, a failed converter in my RV's Parallax 7155 and looking to support future Lithium battery uppgrade. How does the size of the PD4060K compare to the 7155? Is it likely to mount in the same hole or take considerable modifications to fit?

Claire H.

7/9/2026

@Joshua The dimensions of the Parallax 7155 are 7" long x 14" wide x 11 3/4" tall, the lower converter section is 9.5" long x 7" deep x 4" tall. The Progressive Dynamics part # PD4060K is slightly smaller at 12 1/4" long and 8 3/4" wide and 7 1/4" deep. It requires a cutout that is 10 3/4" long x 7 1/4" tall to fit. Your current cut out for the Parallax should be similar in size so only minor modifications would be needed to make the Progressive Dynamics converter fit.

Joshua

7/9/2026

@ClaireH Thank you for the dimensions. Sounds like the PD6060K might have a smaller footprint than I want to use. I'd have to make a filler panel to locate it in the same place. I'll need to measure my rough cutout, but it looks like the PowerMax PM67VR, PowerMax PM98FR, or WFCO WF86FR might be closer matches in size. The idea of wireless lighting control on the PM68FR sounds interesting, though I don't have powered slides or awnings to use with the latching circuits.

Claire H.

7/9/2026

@Joshua I'm not as familiar with the PowerMax since they're relatively new to us, but WFCO has always been an excellent brand. It looks like the cutout dimensions are almost identical for the two and a better match to your current set up like you mentioned. The wireless aspect of the PowerMax unit is interesting, but if you don't have slides or awnings with latching circuits may not be worth the extra price if you aren't able to use that feature.