Bench Power Supply for Automotive Stuff up to 30A - Page 1
Forum section: electronics / beginners

author: meshtron
author_rank: Regular Contributor
timestamp: January 07, 2024, 01:30:55 am
content: I've been testing with an AGM battery that I keep charged all the time, but now that we're playing with higher current, the voltage drops on it pretty fast. So, I'm looking for a switching desktop supply that will output 12-15V at up to 30A. My main goal is to be able to power things up and get a quick read on approximate current draw.I'm not super concerned about accuracy of voltage or current, nor about ripples unless they're really extreme. But, I'd like to invest in something that's going to last me for at least a few years until I either flame out on my project or generate enough income to upgrade to a higher-quality/precision unit.I foundthis one on Amazonwhich seems to have the specs, but I don't know enough about using them to know if these numbers are real or just theoretical.Thanks for any direction! I'd say my budget is up to ~$450 if needed. But, I'd rather avoid something I have to disassemble/modify/etc. - I have way more than enough projects to keep my occupied!

author: mawyatt
author_rank: Super Contributor
timestamp: January 07, 2024, 01:34:05 am
content: We have a Korad KWR102 300W 30V/30A that's working well for us.Best,

author: bdunham7
author_rank: Super Contributor
timestamp: January 07, 2024, 01:40:43 am
content: Do you need it to be variable or have a constant-current function? If not, there are inexpensive open-frame SMPS models available from Megawatt and probably Meanwell that put out 13.8V (usually with some adjustment trim available) at 30A. Or, if you want to avoid the noise of a cheap-ish SMPS, you can get an old boat anchor like this:https://www.ebay.com/itm/314762514453

author: Psi
author_rank: Super Contributor
timestamp: January 07, 2024, 01:42:56 am
content: Do you actually need to draw 30A, i ask because if you need 30A you might want to get something that will do a bit more than 30A. Just to give yourself some margin.An open-frame powersupply will be much cheaper and a lot more options for over 30A

author: meshtron
author_rank: Regular Contributor
timestamp: January 07, 2024, 01:52:31 am
content: Thanks, all!- I do not currently have any need for a constant-current function- I hope to rate a future product up to 30A, so @psi your point is well-made and I'd like to have some headroomThe one I linked says it's 900W, not sure if that means it can exceed 30A at 12V or if 30A/30V are absolute, independent maximums. I'll check out the Korad that @mawyatt noted.

author: Psi
author_rank: Super Contributor
timestamp: January 07, 2024, 01:54:20 am
content: A lot of the open-frame powersupply have a little voltage adj trimpot next to the output terminals, so you can adjust it up or down 2V or so.Some have a wide adjust range than others.

author: meshtron
author_rank: Regular Contributor
timestamp: January 07, 2024, 01:55:31 am
content: Quote from: mawyatt on January 07, 2024, 01:34:05 amKorad looks nice but 300W won't quite get us there. Thanks for the suggestion!

author: Psi
author_rank: Super Contributor
timestamp: January 07, 2024, 01:59:55 am
content: There are 12V 50A open frame psu's for like $40 on aliexpress.I'm not saying they are good onesbut they probably work ok for the price.As recommended above, check out Meanwell brand.

author: Psi
author_rank: Super Contributor
timestamp: January 07, 2024, 02:08:40 am
content: Just came across this beast. I'm not saying to get it, but 1500W at 13.5V for USD$97Looks to have volts adj and even amps adj.https://www.aliexpress.com/item/1005003725181022.html

author: meshtron
author_rank: Regular Contributor
timestamp: January 07, 2024, 02:25:11 am
content: Quote from: Psi on January 07, 2024, 02:08:40 amThat's a monster, but I really would like a current (and preferably voltage) readout. Did get me poking around Aliexpress, though and sure enough I found the unit I linked above from Amazon. They havethis 15V, 60Aversion that seems like it will do the trick!

author: Smokey
author_rank: Super Contributor
timestamp: January 07, 2024, 02:31:49 am
content: It's not the same class of solution as a proper bench supply, but I'm pretty sure a 1500W ATX computer power supply will output like 100A on the 12V rail.

author: ppptran
author_rank: Newbie
timestamp: January 07, 2024, 03:47:54 am
content: Hi , you could take a look at some industrial grade power supply for Base Station ( 4G LTE station).Its normally provide upto 60V and 30A. They set it at 53.3V i think for floating battery charge.I have 1 of the old ZXD1500 ( i think its from ZTE). My buddy gifted me this power supply .After small modification ( I put 2.2K resistor in parallel with it's R95 resister, it can crank up to 48V or 12V, within this range, without the parallel resister, it goes all the way up to 60V , which is overkill for me).

author: enut11
author_rank: Super Contributor
timestamp: January 07, 2024, 09:05:31 am
content: second hand 12v server power supplies are available from about 500W up. just need a small mod to start them up in stand-alone mode