Appreciate some help with adding an AUX battery

[Adamc1303]

I have been taking the kids camping pretty often and the power station we had wasn’t really cutting it. I decided to upgrade to an EcoFlow Delta 2 which has 1024WH and can run at 1,800W output. I also added the EcoFlow alternator charger which is great because it outputs 800W and charges the Delta 2 in a little over an hour. I thought about going with a regular Lifepo4 battery and a dc to dc charger and then an inverter but I couldn’t find anything that would charge a battery as fast as the alternator charger which only works with EcoFlow power stations. I am not saying that a faster charger doesn’t exist, I just didn’t find one. If something does exist I would love to know.

I got the Delta 2 to fit under the rear passenger side seats by removing the JBL amp which I never used anyway. I would like to expand the capacity of the delta 2 using a lifepo4 battery but everything I am finding online talks about taking a battery and having it charge the power station using xt60i cables. That’s fine, but how do I get the battery charged? I have watched so many YouTube videos and they all say expand capacity, yes you are expanding capacity but how do you get the battery charged in order to expand the capacity of the power station? I am really new at this electrical stuff and I know that many on here are very experienced and knowledgeable. I had an idea and would like to know if it would work and if these are the correct parts to use.

Use an AC to DC charger and plug it in to a 110v output plug on the power station and then to the life Po4 battery.

Use a DC to AC inverter from the life Po4 battery to power things like a fridge etc …

Now the alternator charger is charging the power station to 100% in about 80 minutes. That power station charges another battery (not sure on speed though). I use the power station for some things and the extra battery for other things.

Would this setup work? How do I know how much input the life Po4 battery can handle? I would use the highest rated charger as long as I am not overdoing it.

The reason I chose a DC to AC inverter off the battery is because I don’t see any DC to DC inverters. I need to something that connects to the battery for output and then carries the power to plugs.

Am I losing or wasting any power by going from 110v from the power station then converting it to DC so it charges the battery and then converting it back to AC for the output?

Below are the items I was looking at.

12V 100Ah LiFePO4 Battery Group 31 Lithium Battery With Built-in 100A BMS, 1.28kWh Up to 15000 Deep Cycles Rechargeable Battery for RV, Marine, Solar System, Van, Trailer, Backup​

LiTime 14.6V 40A Lithium Battery Charger Mountable for 12V LiFePO4 Lithium Battery with LED Indicator and ON/Off Switch, AC-DC Smart Charger for 12.8V LiFePO4 Lithium Batteries, 40A Fast Charging​

500W Power Inverter, Car/Light Truck 12V DC to 110V AC Converter Dual 2.4A USB Ports Car Charger Inverter with Cigarette Lighter Ports for Smartphones Laptops Tablets​

Thanks,

Adam

 

[Adamc1303]

Anyone? Anything?

 

[ADVAW8S]

I would recommend finding a shop that can assist you. Electrical is something you don't mess around with. If you lived in Australia, you would need an auto electrician setting it up and certified that it was done correctly.

 

[Adamc1303]

It's already setup. I already installed the Ecoflow power station and alternator charger. I am wanting to add to it.

 

[anand]

You have a lot of things going on that aren't really all that necessary or helpful.

Stacking the Ecoflow and a separate battery seems like a really roundabout way of getting to an end goal.

Some things to consider: each time you convert from AC to DC, or DC to AC, there's a loss in efficiency. Depending on the exact equipment making this conversion, this could be up to a 20% loss in power/efficiency per step.

You mentioned going to AC to power a fridge, that's a double loss in efficiency (assuming you're using an automotive grade fridge like Dometic, ARB, National Luna, Snowmaster, Engel, Iceco, etc); as the power is going from DC to AC (to the fridge) and then internally in the fridge from AC back to DC. Even assuming the total loss is 20%, you're effectively losing that much battery capacity due to conversion losses alone.

As @ADVAW8S suggested, getting in touch with a local shop who has experience with these sorts of set ups is probably your best bet.

A tidbit that you mentioned was your choice in going with the Ecoflow because it has an 800w charger and none of the LiFePO4 setups you found could do that. The Victron Orion XS DC-DC charger outputs 700w (as does the Redarc BCDC1250A and their new BCDC Alpha), there are several DC-DC chargers that output more than that. Additionally, in the case of the Victron (and I would imagine the Redarc), they can be stacked in a parallel configuration assuming the alternator can keep up (the Victron at least can also be turned down, so you could run a pair at 40A each or whatever value you want)

 

[parb]

I think I get your question.
Your current system sounds like a 1024wh battery and an 800w DC to DC charger.
That translates roughly to a 85ah battery and a 55A DC to DC charger.

If you want to integrate that into a car setup I would double the battery to a 150ah battery and a 50A DC to DC charger.

That is this DC to DC charger

BCDC Alpha 50A DC Battery Charger

Perfect for charging batteries in a range of recreational vehicles, REDARC’s BCDC Alpha50 is a rugged 12V, 50A DC to DC battery charger, ensuring you’re always charged and never stranded.

www.redarcelectronics.com

This type of battery (which i believe fits in the battery mount location under the passenger side rear seat with the GP factor mount)

Alpha150 12V 150Ah Lithium Battery

Extra-long lifespan and huge discharge rate make this the ultimate lithium battery.

www.redarcelectronics.com

And for ac power you'd get one of these inverters. 2000W which is close to the 1800w of the Ecoflow.

2000W Pure Sine Wave Inverter

Power your sensitive 110V electronics and appliances when standard mains power isn't availabe with REDARC's 200W inverter. Shop online now.

www.redarcelectronics.com

I think you can fit the inverter inside the driver's side trunk sidewalls with an outlet in the wall. The rest should fit under the seat. It supports solar panels so you can charge the battery when parked.

It's a bit more money but it's built to last which I don't think the Ecoflow is. And it's roughly double the battery capacity.

Now Im no expert in this but this is the setup I'm considering.
I would add some 12v ports and maybe some powered USB ports but that's nothing in the grand scheme of things. You can get any recent overland shop outfit your car with this.

This is well proven tech in the overland community.

Good luck!

 

[Adamc1303]

This is the info I needed!

I have a larger Delta 2 MAX arriving tomorrow. If I can get it to fit under the seat I will just swap it out for the Delta 2 since it's more simple and also sounds a tad cheaper. If it doesn't fit I will start working on a new setup and will probably be back on this thread with some more questions. I cannot stress my appreciation to the members that replied here. This was driving me crazy!

Adam

 

[Adamc1303]

You have a lot of things going on that aren't really all that necessary or helpful.

Stacking the Ecoflow and a separate battery seems like a really roundabout way of getting to an end goal.

Some things to consider: each time you convert from AC to DC, or DC to AC, there's a loss in efficiency. Depending on the exact equipment making this conversion, this could be up to a 20% loss in power/efficiency per step.

You mentioned going to AC to power a fridge, that's a double loss in efficiency (assuming you're using an automotive grade fridge like Dometic, ARB, National Luna, Snowmaster, Engel, Iceco, etc); as the power is going from DC to AC (to the fridge) and then internally in the fridge from AC back to DC. Even assuming the total loss is 20%, you're effectively losing that much battery capacity due to conversion losses alone.

As @ADVAW8S suggested, getting in touch with a local shop who has experience with these sorts of set ups is probably your best bet.

A tidbit that you mentioned was your choice in going with the Ecoflow because it has an 800w charger and none of the LiFePO4 setups you found could do that. The Victron Orion XS DC-DC charger outputs 700w (as does the Redarc BCDC1250A and their new BCDC Alpha), there are several DC-DC chargers that output more than that. Additionally, in the case of the Victron (and I would imagine the Redarc), they can be stacked in a parallel configuration assuming the alternator can keep up (the Victron at least can also be turned down, so you could run a pair at 40A each or whatever value you want)

I am running AC to the fridge because the Ecoflow has just one cig lighter DC output and I run two drawer fridges. One as a fridge and one as a freezer. I go out with my 3 growing boys and let's just say they consume a lot of food . I got a cig lighter splitter but the Ecoflow didn't really like it. It was causing a lot of glitching. When I plus the Ac plug into the EcoFlow and the power goes through the fridges power brick which I guess converts it to DC, does that cause an inefficiency?


Thanks,

Adam

 

[anand]

When I plus the Ac plug into the EcoFlow and the power goes through the fridges power brick which I guess converts it to DC, does that cause an inefficiency

Yep, that's the double inefficiency... DC to AC to DC

 

[parb]

You're probably overloading the fridge/freezer combo on that one circuit.
Or the power from the compressor in the fridge is dirty and ecoflow doesn't like it.

Fridges typically use a compressor. It's basically an electric motor. That type of load tends to be very noisy with electrical feedback sent back into the power line. Or maybe the Ecoflow is some weird hybrid modified sine wave that gets uglier under load. I looked for the in the manuals but they didn't call that out. I saw some scope traces which suggested the power gets ugly under load. It's why I think pure sine wave inverters are the better choice even though they cost more. Your sensitive electronics will thank me.