DIY Ego battery power station project

dc443 said:

I think playing around with a project like this would be a great way to get me back into messing with lithium batteries.

I collected a few EGO tools and have a 10Ah and 5Ah pack as well as several 2.5’s. I know i can repurpose and hack one of my 2.5 chargers (I have 4 of them) into a battery mount for a DIY power station.

I would ideally get a good (victron??) 1500 or 2000 watt inverter to build a battery bank power station I could use around the house. My thinking is that this unit could have some wheels and maybe host a few hundred 18650s, as I do have several thousand 18650 cells I have been procrastinating from repurposing. And have a built in cannibalized EGO charger for connecting an EGO battery as a power source. By doing the diy ego charger slot first, i can bring this rig online before i continue to work out how I would spot weld the 18650 based pack for it. Furthermore, because ego batteries are already being separately charged, this lets me also skip developing a charging system.

i would ideally like to be able to confidently power all reasonable appliances, including motorized items like my electric pressure washer and such, i would also love to have a way to use it as an equivalent of an emergency jerry can for my Tesla, though the practicality for that would come down to if i give it a 240v inverter, better suited for a separate project I suppose.

My question is: has this been done before? what type of inverter would i need to be able to confidently run powerful corded power tools and such? I would obviously also need to make sure wiring is sufficient for 15 or 20A and consider how i should make a temp safety cutoff and such but methinks it would just work (especially for more typical appliances) just directly wiring the battery into the inverter here.

I found this is the most detailed page on these batteries so far: https://endless-sphere.com/sphere/threads/understanding-and-using-ego-power-batteries.93563/ but I guess I'm looking for tips and gotchas ahead of getting started.

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Brucey said:

Are you outside the US? Otherwise a pheonix 48/1200 will only give you 120V, not 240V, and they can't be paralleled together for split phase.

Unless you are talking about a multiplus 48/1200, in which case you must be outside US as they are only just recently introducing 120V versions of the multiplus 12/500 and 12/1200 here.

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• This Victron Energy Inverter allows you to power domestic equipment requiring 120VAC or 230VAC, using leisure or automotive batteries rated at 48-Volt DC
• The pure sine wave output delivers 1200VA Continuous power, 2200-Watt peak power with high efficiency, 3-Watt draw in zero-load power ECO mode
• This inverter can be operated and monitored with computers, tablets and smartphones because of the VE.Direct communication port. Cables and dongles are sold separately
• High start-up power is used to start loads such as power converters for LED lamps or electric tools. In ECO mode, the inverter will switch to standby when the load decreases

dc443 said:

The victron datasheet says “(Adjustable)” for output voltage. So this is massively confusing.

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dc443 said:

Interesting. I’m in the US and referring to this exact item: Victron Energy 1200VA 48-Volt 120V AC Pure Sine Wave Inverter https://a.co/d/4njRcCq

Its description states:

• This Victron Energy Inverter allows you to power domestic equipment requiring 120VAC or 230VAC, using leisure or automotive batteries rated at 48-Volt DC
• The pure sine wave output delivers 1200VA Continuous power, 2200-Watt peak power with high efficiency, 3-Watt draw in zero-load power ECO mode
• This inverter can be operated and monitored with computers, tablets and smartphones because of the VE.Direct communication port. Cables and dongles are sold separately
• High start-up power is used to start loads such as power converters for LED lamps or electric tools. In ECO mode, the inverter will switch to standby when the load decreases

To be honest this checks all of my boxes. This thing also seems drastic overkill for being dedicated to powering computers. I think I already saw a youtube video or two where someone attached this to a dolly cart, which looks to be the thing to do. It should simply be upgraded with 2kWh or so of 18650s or 21700 packs once I get into the swing of things. 5kWh might even be a better balance as I’d prefer something to be more battery than electronics for it to “make sense”. I will aim to design modular packs so I could vary its capacity.

I am definitely unclear on how this thing serves 120V for use in America but I assume it will work like that out of the box when I order it off Amazon. I presume there is a hardware or software (??) switch to get 240v split phase, and that the transformer being sized for 240v is part of why it is huge. If it indeed comes with beefy leads to get neutral, L1 and L2 access I’ll be pleasantly surprised.

240v capability is gonna be a treat, as I’d get much better efficiency (from what I understand) using it as a backup power boost for my Tesla among other benefits like being able to run any 240v appliance (industrial robots? I dunno) which I otherwise couldn’t really do at all right now. I guess 1200VA would only provide 5A on 240V so car charging would remain impractical.

What is practical for sure is pressure washer. I’m tired of worrying about spraying too close to the power socket. Running it off battery would obliterate that awkwardness.

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dc443 said:

Maybe the listing is wrong and this is indeed 120v only, in which case I’m calling into question now why it really has to weigh 16lb.

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dc443 said:

The victron datasheet says “(Adjustable)” for output voltage. So this is massively confusing.

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bolhuijo said:

I think it's referring to an adjustment in a narrow range.. here is a screen grab from the VEconfig appView attachment 218435

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dc443 said:

Leaning towards a victron 1200va 48v because it seems like it will set me up for many practical use cases going forward including a way to have 240V AC available in the house at all (outside my dryer wall plug). For example once I move on to other equipment for needs where 1200va comes up short, I will be able to repurpose such a victron inverter as a standalone PC UPS backed by lithium; the UPS appliance capabilities can be implemented with some simple computer integration. For computers I will also be exploring DC/DC UPS functionality but I already have enough older computers that could saturate 1kw under load, and I would much prefer to run them behind a UPS but could never justify spending specifically for doing that.

The main problem with the victron is that it is huge and heavy. It being over 7kg will be twice as heavy as the 7lb 10Ah Ego battery. Datasheet also states I'm supposed to use a 30Ah minimum battery with this unit. I guess that's saying that this would be more appropriately paired with 1.5kWh of battery rather than the 500Wh or so that a single 10Ah Ego battery represents. I expect to be able to use the smaller Ego batteries here with this for burst applications. But the inverter in this setup will make it comically overbuilt. I also would want to make it into a platform with dolly wheels on account of how heavy the inverter is. So I am wondering if there is something else that could work almost as well but be a little bit more efficient in terms of specific power (watts per kg)

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EGO Power+ Nexus Escape 400 W 800 W 120 V Battery Portable Portable Power Station Tool Only PAD5000 - Ace Hardware

The EGO POWER+ Nexus Escape 400W Inverter with Pure Sine Wave delivers high quality, clean power to sensitive electronics.The power inverter provides 400 watts of continuous power and 800-watt peak power for devices requiring additional ramp-up power. It can power up to three USB-compatible...

www.acehardware.com