auto charging a LiFeP04 from the grid?

[brewmium]

Hi. I know this is a bit off topic, since it may not include solar... but, maybe not.

I am going to use a power wall (probably from BigBatteries.com) as an all day UPS for my computer, at some point sitting down stream from my solar setup, but if I want to get it going today, How would I charge that thing, from the wall... automatically, as needed?

thanks,
-eric

 

[FilterGuy]

I believe those are 48 volt systems so you need a 48 volt charger that plugs into the AC.

https://www.powerstream.com/48VDC-720W.htm

 

[brewmium]

It’s a 24v battery bank. I see what you are talking about, just at 24v.

Here’s my use case: I want to be able to keep up with 700watts of office. So, I will have the 3KwH battery bank, into a 2000watt pure sign inverter, feeding the office. I’d like to have a charger that mostly catches up with that... or maybe not, as I do have off time to catch up on charging...

So, I guess I need to better understand what 700watts of output means in terms of charging input.

 

[Steve_S]

would suggest a Samlex EVO 2224 which has dual AC input, 1 for genset, 1 for grid. It can be programmed to sense the grid and has a built in ATS (Auto Transfer Switch) all that is needed is a line from inverter to grid 120V/20A plug for the grid side. Priority can be set to Batt 1st, Grid Second or vice a versa. They also have a Solar input port you can attach a Solar Charge controller to. The next version up from 2200W @ 24VDC is the EVO-4024, there is no 3kw option for 24VDC. Samlex, simple, reliable and well backed & supported.

2200 Watt 24V Pure Sine Inverter/Charger | EVO-2224 | Samlex America

2000W 24V Pure Sine Wave Inverter/Charger with 70A Battery Charger + 40A Transfer Switch. Marine grade, heavy-duty power for rv, boat & off-grid. Lithium compatible.

www.samlexamerica.com

See links in my signature for more info as well.
Hope this helps, Good Luck.
Steve

 

[brewmium]

Thanks for the link @Steve_S , but that’s too rich for my blood.

I was thinking of DIYing up a raspberry pie, high/low voltage sense, and a switch to energize a 24v charger.

 

[David in nh]

how about something like this , will do you ups function /transfer switch as well charge battery
https://www.aimscorp.net/24-volt-pure-sine-inverter-charger.html you find them much cheaper on amazon

• 2000 watt low frequency inverter
• 6000 watt surge for 20 seconds 300% surge capability
• Battery priority selector
• AC direct connect terminal Block
• Marine coated and protected
• Multi stage smart charger 30 Amp for gel, AGM, lead and lithium LiFePO4
• Remote panel available
• Auto frequency
• 10msec typical transfer time
• Selectable 25W power save mode (hibernation)
• 7 battery type settings for charger
• Automatic transfer switch

 

[brewmium]

thank you for the link @David in nh , may still be a bit rich for me, especially since I have everything but the grid power to charge battery purchased and ready to go.

 

[brewmium]

Okay @David in nh , I'm chickening out on the DIY charger for my new batteries... have returned the 3000w inverter, and ordered this. net +$500 cost. Thank you for the pointer to this, I'll let everyone know when i have this up and running.

 

[David in nh]

looking forward to seeing how well you set up works,