Page Comparison

• 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)

...

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

PSU:

Supermicro PWS-741P-1R

...

• DC output: 740W, 12V/61.7A

  Assuming our boost groundside convertor supplies 24V DC to the charger:

  If we charge

What convertor to buy?

• Suggestions from Jerry Tian and Ryan Scomazzon : Charger should be able to charge a 7Ah battery (most of our batteries have less capacity than that) at 1C. This means 7A per battery

  • If charging 4 batteries at once, the current will max out at 10.4 A per channel (each channel is 250 W / 24V)

  • Alternatively we could just not use max power, and just charge 2 batteries at once with lower power/current.

...

• • charger must supply 4 x 7A at 24V = 672 W

COTS options:

• AliExpress seems to have the most amount of options and is well priced (but might be a bit sketchy?)

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

Product	Price	Ratings

Specs0-1200 W

Features	Datasheet	Notes
Szwengao

WG-12S2450M

134.68

24V 50A

WG-12S2420M Image Added	50.36 (AliExpress)	24V 20A 0-480 W	High efficiency: 96.6% (@12Vin, 25℃) Non-isolated between input and output 100% full stable current output Support -30 °C environment 100% full load burn-in test OT, OL, LV protections Waterproof level IP67	https://proa2427b-pic7.websiteonline.cn/upload/WG-12S2420M.pdf	Not enough power if we want to charge 4 batteries at once
Szwengao WG-12S2430M Image Added	77.99 (AliExpress)	24V 30A 0-720 W	High efficiency: 95.6% (@ 12Vin, 25℃) Non-isolated between input and output 100% full stable current output Support -30 °C environment 100% full load burn-in test OT, OL, LV protections Waterproof level IP67	https://proa2427b-pic7.websiteonline.cn/upload/WG-12S2430M.pdf	Load is 672W, at 95% efficiency this convertor would have to handle ~707 W input power Theoretically possible but it would be operating near its limit, would leave very little headroom
Szwengao WG-12S2440M Image Added	100.68 (AliExpress)	24V 40A 0-960 W	High efficiency: 97.8% (@24Vin, 25℃) Non-isolated between input and output 100% full stable current output Support -30 °C environment 100% full load burn-in test OT, OL, LV protections Waterproof level IP67	proa2427b-pic7.websiteonline.cn/upload/WG-12S2440M.pdf	More expensive than the 720W option Load is 672W, at 97% efficiency this convertor would have to handle ~693 W input power If charging 4 7Ah batteries at 1C, this convertor would be operating at 693W/960W = 72% capacity, leaving plenty of headroom