DC Power supply - focus on voltage or amperage?

[jlee]

Hi I am from Southeast Asia and there are some DC power supplies lurking around.
Having to live closer to China can have its own benefits and drawbacks (shipping, quality respectively)

I was just wondering if there are a lot of these DC power supplies what should I prioritize in purchasing?
A higher voltage? or a higher amperage?

It seems that the answer is amperage since it affects the rate of charge.
Does anyone charge batteries using this in a 4s or higher config which results in 24 or 48v?
Or do you usually top balance things in basic 12v individually then lump them together later?

Available options are 15v 50a or 30v 30a and some combinations here and there.
What I plan to use this for is both top balancing and charging from low state of charge.

Btw they cost around 200USD should I bite the bullet? or a lower wattage total is enough like 12v 10a?
I also can't verify the quality of the product yet... so it is a risky purchase.

 

[Short_Shot]

Are you doing this once and have time to spend on it? If so just get a cheap 10a unit.

Voltage is irrelevant as long as it can output at least the voltage you need to charge with.

Are you charging individual cells or 12 volt batteries (which are multiple cells in series).

Do you need 24/36/48 volt charging due to having a single battery of that voltage that you can't do individually at 12v?

 

[jlee]

I plan to verify batteries I am going to buy.
Shops here give you 3 days to verify things for refund or exchange unconditionally.
10a given a 100a lifepo4 take 10 hours approximate right?
But I get where you are coming from recommending 10a unit and might start there.

Regarding charging, well to top balance I assume I would have to do it individually at 12v. Or is it ok to go the lazy route and just series/parallel them?

24/36/48 honestly no... not really... but I plan to start in 12v for power backup purpose and probably simple appliances like lights and fans, but eventually scale to 48v to try and powerup more like AC and pumps.

Was just curious what people are usually doing when they get their battery, how do they verify and manage initial charging and what not.
In my part of the world there are a lot of dodgy things, being so close to china there is a 70/30 chance you are being ripped off as there isn't any reputable sellers yet.

 

[Short_Shot]

You're correct on the basic math for time.

If you're going to do more often it may be a good investment for a higher current adjustable voltage power supply. Given the 3 day limitation, it doesn't leave much room.

 

[jlee]

Exactly, hence might go for higher amps for testing ?

I just realized my statement was wrong. Per m6 battery is only around 3.2v so I guess if I want to top balance per piece voltage doesn't matter much ?

 

[Short_Shot]

Exactly, hence might go for higher amps for testing ?

I just realized my statement was wrong. Per m6 battery is only around 3.2v so I guess if I want to top balance per piece voltage doesn't matter much ?

Yeah it gets to a bit complex when dealing with packs vs single cells as well.