USB-C for charging

Battery_Mooch · December 20, 2021, 10:48pm

Thanks for doing that! I’ve been a doubter all along about paralleling supplies (so much depends on the supplies used) but if I am wrong I will be a verrrrry happy person.

Battery_Mooch · December 20, 2021, 10:48pm

Excellent. I am very much looking forward to seeing how this works out!

ShutterShock · December 20, 2021, 10:49pm

Yah for sure. I’ve seen plenty of people do parallel with real psu’s too but with that, you can set the output and they’re much more accurate, no automatic stuff

Same - I’m going to go ahead and order these

And this boost converter

Battery_Mooch · December 20, 2021, 11:05pm

I want to know where the heck MELIFE is finding those IP2721 trigger chips! They’re not available anywhere. Though, perhaps they bought a few hundred thousand before the shortages and are just using existing stock.

Which USB charging adapters were you going to try paralleling?

ShutterShock · December 20, 2021, 11:09pm

Lol good question. Probably haha

I went ahead and ordered the KOVOL one that claims 60W + 60W

jaykup · December 20, 2021, 11:09pm

I’ll let it run for an hour and see

Agreed. Meanwell says you can’t run their HLG switching power supplies in parallel because there is no current sharing feature… however (chargers set to different voltages to see if that matters):

No power supplies connected. 44v 12s battery level

PS set to 51v connected solo

PS set to 53v connected in parallel with the 51v

Pretty clearly shows that it’s sharing current at an equal level. These PSUs won’t go over 4.8A even if shorted. Of course once charger 1 hits 51v the 53v charger will take over… and this is all for an experiment, I’m not charging a 12s battery to 53v haha

Battery_Mooch · December 20, 2021, 11:22pm

That’s what I’m wondering about. I assumed that standard CV power supplies (like in USB charging adapters) would be used. But perhaps the key is using CC/CV power supplies like your HLG’s with their built in CC current limiting.

Diode the outputs, to keep one from possibly feeding into the other since never exactly same voltages, and then let each just current limit to the load.

I don’t think any USB charging adapters use CC/CV supplies though. Just protected CV supplies. CC/CV just isn’t needed for their intended uses.

I think CC/CV supplies with PD interfaces would need to be designed. But then why go USB PD at all. You could just plug a CC/CV supply at the right voltage into the board. Yea, it needs to work with stock USB charging adapters.

jaykup · December 21, 2021, 1:06am

The chargers were warm to the touch but not bad.

I ran it for 30 minutes at 1.66A and the USB boards got to 52C, but only felt warm to the touch.

Then I swapped to two independent USB chargers and ran it for 90 minutes at 2.2A. The USB boards got up to about 75C in some spots measured with an IR gun and were hot but not burning to the touch.

I think as long as you set it up in the open and measure the temps though a charge cycle you will have a good idea of how it will all work together.

marketthrowaway · December 21, 2021, 3:58am

Fuck. Don’t have time to read thread.

Do we have a good/quick & simple USB charging setup for 12s-20s batteries yet?

ShutterShock · December 21, 2021, 4:08am

Tldr not quite

Except for Kevin grael apparently but he didn’t really share details

ShutterShock · December 21, 2021, 4:09am

Sounds promising, I’m kind of intrigued to see how my setup works out. Might not get to it until Jan depending on a variety of things though

Battery_Mooch · December 21, 2021, 4:43am

Nope.
And there never will be. Not by using two USB charging adapters, two cables, two trigger boards, perhaps some diodes, a boost converter, and the needed connectors and wiring.

But since it’s the only way to do this great USB charging idea perhaps we can eventually package it all together better.

marketthrowaway · December 21, 2021, 4:58am

Too many words, not enough make usb c worky

Battery_Mooch · December 21, 2021, 5:28am

Wordy make worky more better. Smaller wordy make worky not work.

Evwan · December 21, 2021, 5:33am

Boosting a 20v5a USBC laptop charger to around 50.4v @1.75a (after inefficiencies and whatnot) is a great solution for a slow charger imo. Or a small commuter board. You can recharge it while you exist (say after a commute) and help preserve cycle life with the slow charge.