12V to 24V Boost Groundside Converter

• Who

  • @Daniel Puratich idea

  • @Tim Gu looking into it

• What

  • Take in 12V and output 24V

  • For powering our 24V battery charger

    • would be massive help at comp and flight tests to be able to charge faster

  • Supply enough power for the charger

    • if the current is really high then this project is going to be waaay out of our skill range

• Why

  • We have 12V server PSUs that are CSA approved

  • We get more power capability out of the charger at 24V

  • we could also just buy this? not sure if it maths out.

Details

Battery charger: HotA F6 Quad Battery Charger (4 x 15 A)

Charger Datasheet

Open	Open

• 1000 W output power limit across the 4 channels, with max current 4 x 15 A.

PSU:

Supermicro PWS-741P-1R Datasheet

• DC output: 740W, 12V/61.7A

What convertor to buy?

• Suggestions from @Jerry Tian and @Ryan Scomazzon : Charger should be able to charge a 7Ah battery (most batteries we use will be around 5.5Ah) at 1C. This means 7A per battery

  • If charging 4 batteries at once, charger must supply 4 x 7A at 24V = 672 W.

  • Ideally the convertor should be rated for well above 672 W (it should have some headroom)

COTS options:

• The product from the following brand is the best I could find in terms of price and provided specifications. Most other products don’t have a datasheet

  • Though it is from AliExpress, is it sketchy to buy this from there?

• Couldn’t really find anything good on Amazon or Facebook Marketplace

• The WG-12S2440M should suit our needs

Usage

• Uses screw terminal connections

  • Is there any designing that has to be done for wiring/harnessing? Diagrams?

• On the output side: 672 W load at 24V - output current is 672/24 = 28 A

• On the input side: Assuming 97% efficiency, input power is ~693 W at 12V - input current is 693/12 = 57.7 A

  • 4 AWG wire?

• Do we need a fuse for the wire carrying high current between the PSU and the boost convertor?