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DIY Portable Power Supply


Spudger
(@spudger)
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Posts: 13
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Last year I went all electric for yard maintenance power tools (EGO mower etc.). So, now I have a couple of 56V batteries that I'd very much like to put to use when I'm not using them for yard work. We do quite a bit of camping, and it would be nice to have a small, portable power supply and an emergency backup for home if/ when the power goes out, or if we need to bug-out in the event of a forest fire etc. (we live in a forested area). There's no reason for me to buy an expensive Jackery (or other) when I've got a perfectly good source of power already.

EGO does make a 150W inverter that plugs into their batteries, but it's a modified sine wave and costs ~$100. For about the same price, I am putting together a much more versatile power supply that should cover a wide range of power needs. I found an adapter with pigtails that plugs in to these batteries, and want to make the power supply modular, so I have lots of options.

I was hoping someone might look over a sketch (sorry, not an Arduino sketch) that I made of what I have planned. I'm open to suggestions or criticism, and am just in the initial stages of putting this together.

Thanks in advance ...  😎                 ... also attached is a pic of my temporary (dining room) electronics bench, just for fun.

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Spudger

The rocket worked perfectly, except for landing on the wrong planet.- Wernher Von Braun


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Spudger
(@spudger)
Active Member
Joined: 4 weeks ago
Posts: 13
Topic starter  

Calling this a power supply is a misnomer, sorry about that, it's a power bank. I may use it as a power supply at times, with the boost buck, but what I really like Bill's nice power supply build, using the Drok Converter with Display.

Spudger

The rocket worked perfectly, except for landing on the wrong planet.- Wernher Von Braun


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Spudger
(@spudger)
Active Member
Joined: 4 weeks ago
Posts: 13
Topic starter  

Had some Ego batteries sitting around, need a power bank. Lithium-ion batteries 10A total @ 56V. (7.5A and 2.5A w/ splitter, so they can be coupled as needed). The batteries supply the Synchronous Buck (Step-Down) Converter, 200W 15A DC-DC 8-60V to 1-36V.

I opted to set the buck Output for 13.6V, Converter is screwed down to Inverter base to help sink any heat away.

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Goals are to keep the overall size to a minimum and keep this portable, while providing short term emergency backup, power for electronics and/ or communications. (i.e. radios, phone, light, charging etc.) Also use it camping.

Have options, use the car or trailer cigar lighter sockets instead of the Ego batteries as needed to power the inverter.

Incorporate a small multiple USB strip, and provide more than one 115VAC plug.

Other DC voltages can be provided using a 60W boost buck converter plugged in to the 12V Outlet buck has various connector pigtails.

This is mainly for camping and emergencies, power outages etc. I'll need to do some testing to see how long it will run a small 26 quart freezer (probably not long enough, but we'll see), or a router, wifi, voip w/ laptop or two. Solar recharge batteries when possible, tall order here in the PNW during the winter months.

It's still a work in progress. As you can see above, I am attaching some guides to one of the battery adapter plugs to keep the inverter from (easily) coming unplugged from the batteries.3M double-sided tape holds the inverter to the adapter plug at the battery. The inverter mount is still exposed on one side, I'll cover that with some metal edge trim, or maybe mount something else there. Perhaps a 18650 USB rechargeable flashlight. Two wraps of 3/4" Velcro to bind things together into a packet and provide a carrying strap.

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I'll have to admit that having these batteries just sitting on the bench all winter was just not an option, I like to keep tabs on batteries, stretch 'em, use 'em... wish they'd had these around when I built my first e-bike. The Wh/ Weight ratio is pretty good, I think.

Next project, upgrading and soldering my Resistance Substitution Box Kit, using some 1% tolerance, 1W resistors.

... and I need to relocate my work area (currently the kitchen table) to another zone.

Ciao

This post was modified 3 days ago by Spudger

Spudger

The rocket worked perfectly, except for landing on the wrong planet.- Wernher Von Braun


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