Inverter avoidance?

[Alex swampy]

Hi all,

I’m working on the electrical system for my transporter and aiming to expand it without adding bulky components like an inverter. My current setup:

• Battery: 100Ah lithium with built-in temperature control.
• Charging: Victron 30A DC-DC charger as the sole charge source.
• Current Load: Only accessory connected is a diesel heater.

What I Want to Add​

1. LED Lighting: Very low power demand.
2. USB/USB-C Charging: For phones, tablets, cameras, and a satellite phone.

I’m trying to keep things as efficient as possible by avoiding DC-AC-DC conversions, which an inverter would introduce. Instead, I want to directly integrate a USB-C Power Delivery (PD) solution to handle higher-power device charging (65W+).

Challenges with USB-C PD​

• Most outlets claiming “65W PD” seem to max out at 5V/3A (15W), falling short of the true PD spec that delivers 20V at 3.25A (65W).
• For USB-C PD 3.0, which can provide up to 100W (20V/5A), I’m unsure where step-up circuitry would fit in the compact USB outlet designs I’ve seen.

My Thinking​

By directly stepping up the leisure battery’s 12V to 20V for USB-C PD, I can:

• Avoid inefficiencies from converting DC to AC (via an inverter) and back to DC.
• Save physical space by bypassing the need for an inverter entirely.

Questions for the Community​

1. High-Wattage USB-C Options: Has anyone found reliable hardware for 65W+ USB-C PD direct from a 12V system?
2. Fusing and Safety: What fuse size is appropriate for a 100W USB-C PD outlet? How can I independently fuse multiple USB outlets?
3. Energy Efficiency: Does anyone have experience comparing inverter setups vs. direct DC-DC converters for USB-C PD in terms of real-world efficiency?

Any advice or recommendations are greatly appreciated. I’m committed to keeping the system safe and as efficient as possible while future-proofing for additional needs.

Anyone have any experience with items such as the one show? Are they reliable? Seems like a neat way to solve my issues?

Id like to add that I may be completely getting the wrong end of the stick with this, and wont take any offence to being pointed in the right direction or correction of any fundamental misunderstanding, we are all learning in life!
Thanks in advance for your help!

 

[Salty Spuds]

Have a look at Buck converter’s,cheap, adjustable & reliable. I use one for charging a lithium battery from a standard battery charger. Loads to choose from, here’s an example.

https://amzn.eu/d/goIs08P

 

[admrobrts]

@Alex swampy did you make any progress on this upgrade?
Looking to do something similar. Have no need for an inverter other than to charge a MacBook while on the road. Would much rather just charge if via USB-C.

Will look into the Buck Converter as Salty Spuds suggested.