EG4 6500EX Grid-charged backup system

[rikka]

We would like to install a EG4 6500ex battery-powered system like the one described in this video:

We originally were looking into the Delta Pro, but this one looks like it would be cheaper, power longer, and more affordable to upgrade. However, the installation and connections seem to be much more complicated so I had some questions.
The sole intent of this system is to provide backup power during outages. We have occasional random outages throughout the year that last a few hours each. We had two times where trees toppled the power poles - these took about 20-24 hours for the power company to repair.
We do not plan on powering the entire house. We would only like to power some circuits (TV, computer, fridge, freezer, maybe microwave or toaster oven only if possible). We will not be powering heat/AC or anything that uses 240V (so no split phase). We want to use a manual transfer switch for this with 6-10 circuits. We have no need of an automatic transfer switch and don't want a interlock (as we don't want to power the whole house). We would switch the manual switch on to power what we need, but leave some of the circuits not connected to this switch on to give us indication of when the grid power is restored.
We do not have solar. We do not (at this time) have any intention of adding it. Maybe someday in the future we'll get some small panels but only to charge the battery. We we not be doing any time-of-day savings. This is exclusively for backup during outages.
We don't really want a natural gas generator due to cost, noise, and need. Since we've had the pole in our backyard topple over and it only took a day for them to replace the entire thing, we don't anticipate needed to run our house for days.
We would likely hire an electrician for the wiring.

I have done a lot of research to try to understand what I'm getting into but I'm still confused on a few things.
1) We will be charging this exclusively from the grid. Does this need to be wired directly to the breaker box on it's own dedicated circuit? Since the manual suggest 6-4AWG wire, I'm assuming the answer is yes. I'd prefer to plug it into an outlet like the Delta Pro, but I don't want to melt or overload anything.

2) I believe this needs a dedicated 60amp breaker to charge from the grid, correct? Is installing a standard AC breaker okay? The manual mentions AC and DC, but I think the DC breaker is only needed if charging from solar. Is this correct? Is a "chargeverter" necessary for this type of setup? Or do I only need 30amps?

3) Can I wire a generator cord to the AC Output of the 6500ex so I can plug it directly into the manual switch box? Would I just be connecting 3 wires (no red since this isn't split-phase)?

4) I've read about "neutral bonding" but I'm having a hard time wrapping my head around this. I've watched a video on how the manual transfer switch connects to the main panel and it seems like it's just an on/off switch between the black wire going into the circuits I want. It had one ground and one neutral going to the ground and neutral bars in the box.
When you connect the inverter to the breaker box, the black wire would go to the circuit, a green to ground bar, and a white to neutral bar.
Is this all correct? The neural bonding screw issue confuses me but most threads I've seen are discussing either split-phase or solar charging, neither of which apply to me.

5) When I'm not charging the battery (since it should last a couple months without draining too far), can I just turn off the dedicated circuit to shut off power to the inverter and turn off the battery? Or should I just turn off the battery but leave the inverter on? I don't want the battery charging all the time to prolong the life.

6) Are there any other concerns I need to be aware of or precautions I need to take?

It seems I need to just
a) Wire a manual transfer switch between the 6 circuits I want and connect the ground and neutral to the ground and neutral of my main panel.
b) Wire the the AC input of the inverter to a dedicated 60amp AC breaker in the main panel.
c) Wire the AC output of the inverter to a generator cord to plug into the manual transfer switch.
d) Connect the battery(ies) to the inverter.
e) Turn the battery and/or the inverter off and power on when I need to manually switch to backup power (or charge the battery)

I'm sorry this is so long, but I'm trying to see if this is a realistic project or if I need to spend a lot more on a Delta Pro + extra batteries. Thank you for any help you can provide.

 

[dcg9381]

We have no need of an automatic transfer switch and don't want a interlock (as we don't want to power the whole house). We would switch the manual switch on to power what we need, but leave some of the circuits not connected to this switch on to give us indication of when the grid power is restored.

You already have a grid disconnecting manual transfer switch so that's good.

I have done a lot of research to try to understand what I'm getting into but I'm still confused on a few things.
1) We will be charging this exclusively from the grid. Does this need to be wired directly to the breaker box on it's own dedicated circuit? Since the manual suggest 6-4AWG wire, I'm assuming the answer is yes. I'd prefer to plug it into an outlet like the Delta Pro, but I don't want to melt or overload anything.

You can use a plug that is rated for your charge rate. If you were 240V, I'd say 14-50P. I know there is a 30A plug for 120V - the TT-30R, but don't know about 50A rated. The TT-30R would be single outlet, dedicated circuit.

You can also direct wire. Yes, you need a dedicated circuit and breaker.

6 AWG copper typically can handle 50-60A peak. Depends on length of run.

You can set the charge rate on this inverter, so there are lots of options. You could use a normal 15A outlet (confirm that this charge rate - 12A is available in the manual). I absolutely no reason (in this case) where you really need to "rapid charge" these batteries.

2) I believe this needs a dedicated 60amp breaker to charge from the grid, correct? Is installing a standard AC breaker okay? The manual mentions AC and DC, but I think the DC breaker is only needed if charging from solar. Is this correct? Is a "chargeverter" necessary for this type of setup? Or do I only need 30amps?

It needs a breaker that matches the wire gauge and set charge rate. Generally:
6 AWG on 50A breaker.
10 AWG on 30A breaker
12 AWG on 20A breaker
(copper wire)

The chargeverter use case seems to be focused on "dirty power" (generators). I see no reason to use it for what you want to do.

Understand residential breakers are rated for only 80% of their listed rating for continuous use. That's why you see EV chargers set to do 48A on 60A circuits. (80% of 60A = 48A)

3) Can I wire a generator cord to the AC Output of the 6500ex so I can plug it directly into the manual switch box? Would I just be connecting 3 wires (no red since this isn't split-phase)?

Yes. Again, assuming the generator cord is 50A capable, typically 6 AWG. 3 wires is correct. Neutral, Ground, Hot. It's a fat cord.

4) I've read about "neutral bonding" but I'm having a hard time wrapping my head around this. I've watched a video on how the manual transfer switch connects to the main panel and it seems like it's just an on/off switch between the black wire going into the circuits I want. It had one ground and one neutral going to the ground and neutral bars in the box.
When you connect the inverter to the breaker box, the black wire would go to the circuit, a green to ground bar, and a white to neutral bar.
Is this all correct? The neural bonding screw issue confuses me but most threads I've seen are discussing either split-phase or solar charging, neither of which apply to me.

Neutral Ground bond still applies to 120V case. And it's important.
What you need to understand is that wherever power comes from, a neutral gound bond needs to exist at that point and that point only.
It's a little tricky with the EG4-6500 because they've changed the bonding screw and have 2 distinct versions of firmware and leave people to figure it out.

I think how this is configured may depend on what's going on in your transfer switch. I need to know the configuration of the transfer switch on neutral/ground. If it switches EVERYTHING (hot, neutral ground) over to the generator side, you'll need mobile firmware and to add a bond screw. If it just switches a hot, then existing firmware and no bond screw is correct.

5) When I'm not charging the battery (since it should last a couple months without draining too far), can I just turn off the dedicated circuit to shut off power to the inverter and turn off the battery? Or should I just turn off the battery but leave the inverter on? I don't want the battery charging all the time to prolong the life.

I would turn off both, but someone else can weigh in. The inverter itself idles at 120 watts or so, no reason to leave it on.

6) Are there any other concerns I need to be aware of or precautions I need to take?

You've got the basic ideas. All plugs/receptacles/wire must match your rated amperage. For the 6500, that's about 50A (max capacity). I wouldn't pull more than 48A continuous from it.

What you're missing:
If you're going to use the EG-4 LL batteries, they are rated for 100A output. I would assume they can do 80% of that. You can find videos where one battery isn't enough, two is generally the minimum needed if you want to get anywhere near rated output.

The wire that comes with these batteries is 5 AWG. That's not enough to sustain 80A+ of battery discharge. You'll need to double up the output wires. There are 2nd terminals for this.

It seems I need to just
a) Wire a manual transfer switch between the 6 circuits I want and connect the ground and neutral to the ground and neutral of my main panel.

Let us know how the transfer switch operates.

b) Wire the the AC input of the inverter to a dedicated 60amp AC breaker in the main panel.
c) Wire the AC output of the inverter to a generator cord to plug into the manual transfer switch.
d) Connect the battery(ies) to the inverter.
e) Turn the battery and/or the inverter off and power on when I need to manually switch to backup power (or charge the battery)

I'm sorry this is so long, but I'm trying to see if this is a realistic project or if I need to spend a lot more on a Delta Pro + extra batteries. Thank you for any help you can provide.

 

[rikka]

You can use a plug that is rated for your charge rate. If you were 240V, I'd say 14-50P. I know there is a 30A plug for 120V - the TT-30R, but don't know about 50A rated. The TT-30R would be single outlet, dedicated circuit.

You can also direct wire. Yes, you need a dedicated circuit and breaker.

6 AWG copper typically can handle 50-60A peak. Depends on length of run.

You can set the charge rate on this inverter, so there are lots of options. You could use a normal 15A outlet (confirm that this charge rate - 12A is available in the manual). I absolutely no reason (in this case) where you really need to "rapid charge" these batteries.

I was unaware you could set the charge rate. I checked the manual again and it looks like the minimum charge rate is 10A (and possibly increments in steps of 10). So I could set it to 10A and use a normal 15A outlet, or set it to 20A and use a 30A outlet. I think that's as high as I would go. Regardless of what I choose, I'd just need to match the wire gauge to the breaker rate for all the related wiring so I don't burn my house down.

Neutral Ground bond still applies to 120V case. And it's important.
What you need to understand is that wherever power comes from, a neutral gound bond needs to exist at that point and that point only.
It's a little tricky with the EG4-6500 because they've changed the bonding screw and have 2 distinct versions of firmware and leave people to figure it out.

I think how this is configured may depend on what's going on in your transfer switch. I need to know the configuration of the transfer switch on neutral/ground. If it switches EVERYTHING (hot, neutral ground) over to the generator side, you'll need mobile firmware and to add a bond screw. If it just switches a hot, then existing firmware and no bond screw is correct.

Actually, I don't have the switch yet. I wanted to make sure I understood the neutral ground bond before getting something. I've seen other users mention the Reliance 30A switch which apparently does not switch neutral. Since it only switches hot, it sounds like I should be able to use the neutral and ground bar in the existing panel.

What you're missing:
If you're going to use the EG-4 LL batteries, they are rated for 100A output. I would assume they can do 80% of that. You can find videos where one battery isn't enough, two is generally the minimum needed if you want to get anywhere near rated output.

The wire that comes with these batteries is 5 AWG. That's not enough to sustain 80A+ of battery discharge. You'll need to double up the output wires. There are 2nd terminals for this.

This is good to know. I was on the fence about 1 or 2 batteries, but this sounds like I should just go with at least 2 and make sure to double up the output wires. We're going to try to minimize our power usage when on battery as much as possible so I doubt we'll use 80A, but it's better to be prepared in case we change our minds down the line.

This puts me in a much more comfortable position and makes this seem like a more realistic job. The wiring was my biggest concern, but I'm starting to be able to picture and understand everything much clearer in my head after this. Thank you so much for your help!

 

[dcg9381]

This is good to know. I was on the fence about 1 or 2 batteries, but this sounds like I should just go with at least 2 and make sure to double up the output wires. We're going to try to minimize our power usage when on battery as much as possible so I doubt we'll use 80A, but it's better to be prepared in case we change our minds down the line.

Match your input breaker to the highest possible output of your batteries (and their wire). I'm not comfortable with more than 60A per battery based on 5AWG, but last time I tested those wires were cool at 70A.