Battery Charger to Charge Controller

[Hosstyle]

I'm a super noob and very broke so I'm looking at "work with what I've got" solutions. I have a 12V LIFEPO4 battery and would like to setup a backup (wall power) charging option. I inherited a Drok-like variable voltage bench charger. It's 10 amps, so for my 12v system, I'm charging @ 14.4volts X 10 Amps. This is sloooooow.

I also have a spare Epever charge controller and am thinking to set the bench charger to say, 60v and feed it into the charge controller (well within voltage range), with the now higher amperage 14.4v output charging the battery over suitable awg cabling.

Any obvious issues I'm missing? Anybody doing something like this?

 

[sunshine_eggo]

Here is a response from the founder of MidniteSolar:

Testing MPP Charge controller function with bench power supply?

Anyone know if you can use a 5A-60V DC power supply to test functioning of a MPP charge controller. I have a all in one inverter with charge controller that I am testing in my shop before shipping to where it will be installed in MX. Everything is working great but don't have PV panels here and...

diysolarforum.com

 

[adamantium]

I'm a super noob and very broke so I'm looking at "work with what I've got" solutions. I have a 12V LIFEPO4 battery and would like to setup a backup (wall power) charging option. I inherited a Drok-like variable voltage bench charger. It's 10 amps, so for my 12v system, I'm charging @ 14.4volts X 10 Amps. This is sloooooow.

I also have a spare Epever charge controller and am thinking to set the bench charger to say, 60v and feed it into the charge controller (well within voltage range), with the now higher amperage 14.4v output charging the battery over suitable awg cabling.

Any obvious issues I'm missing? Anybody doing something like this?

It sounds like you want to up the voltage on the Drok so that you can up its power output about 4x. Is that correct? Sounds like a great idea to maximize what you have available. That would effectively give you 60V output at 10A on the Drok and 600W charging instead of 150W charging out of the charge controller. Since it is the same current output on the Drok, you shouldn't need different cables for it. Like you said though on the charge controller output you will need 8ga stranded copper cable at least.

The only thing I see as a potential road block is the current rating for both the Drok and the charge controller. I don't know much about the Epever charge controller. I assume that the charge controller can accept 60VDC and output 14.6V or the 14.4 you want at 40A. I see 20A and 40A models out there. That is the power the drok will be pushing to it. 60V * 10A = 14.6V * 41A output. The Drok may not be able to handle 10A at 60V continuously either. The specs on those little buck converters are often exaggerated. You will definitely need a good fan blowing on it. Even if it can't do the maximum you should get somewhere in between that is much better than you are getting now. You are making a 40A charger that should charge a 100Ah LiFePO4 battery 100% in 2.5 hours instead of 10

That's my two cents. It would be great to hear how it goes for you. I do stuff like this for fun too. Just made my own UPS.

 

[mikefitz]

Epever charge controller and am thinking to set the bench charger to say, 60v and feed it into the charge controller

You could try this, but Dork type power units don't have ideal current limiting. With the Epever searching for maximum power the power unit may just fold back or even fail or become unstable.

 

[Hosstyle]

Awesome! Thanks for the info guys. Yeah, the bench supply seems to max out at ~480watts from other testing, but that will still be far and away superior. Yes, 60v is well within the range for this Charge Controller. It's max 150v.

@mikefitz , Concern noted... Sounds like I will also be inadvertently testing the over-current protection on the bench supply as well. I will report back with success or hilarious failure