Everything in this article is built on one source video: Martin Johnson — Off Grid Living's EASIEST Off Grid Solar Power System Battery Bank, a build that has racked up 5.4 million views. Martin runs a homestead in northern Idaho, and in this video he performs the biggest upgrade his solar system has ever had: replacing four 230Ah 6V flooded lead-acid golf-cart batteries with eight 100Ah Battle Born LiFePO4 batteries, rewiring the whole shed to 24 volts, installing new Victron charge controllers with Bluetooth monitoring, and then showing real performance through several days of rain and cloud. If you want to watch the build before reading the breakdown, it is embedded here:
Why did this build get 5.4 million views? Because it answers the question every off-grid owner eventually asks: can I swap my old lead-acid bank for lithium without hiring an electrician? The answer Martin demonstrates is yes — with careful planning, safe disconnection, and methodical wiring. We have written this up the same way we approach battery sizing guides on this site: step by step, with the numbers Martin actually measured, so you can judge whether this upgrade path fits your own cabin, RV or shed.
Before the upgrade, the solar shed ran on four 230Ah 6-volt flooded lead-acid batteries — the same "golf cart" batteries used in thousands of off-grid systems. Wired as two series pairs then paralleled, they formed a 24-volt bank rated at 230Ah, but flooded lead-acid batteries only allow you to use about 50% of rated capacity without damaging them. So the practical usable capacity was about 115Ah. The rest of the original system included a 2,000W Ames 24V inverter-charger, a MidNite Solar Classic 150 charge controller, a Victron battery monitor with shunt, and a main fuse protecting the interior wiring. Outside, six 300W-plus solar panels fed the shed.
This is the exact configuration most homesteaders and RV owners start with — and the exact point where they hit the wall: 115 usable amp-hours at 24V is roughly 2.8kWh, which disappears fast on a cloudy week. The upgrade path shown in the video is the one most people take next, and it is worth understanding before you commit to buying lithium.
Martin spells out his reasons for choosing Battle Born LiFePO4 cells, and they line up with the chemistry's well-known advantages over flooded lead-acid:
Usable capacity nearly doubles per watt-hour of rating. The new eight 100Ah 12V batteries are wired into the same 24V system as 400Ah — and because LiFePO4 batteries can be discharged to 100% depth without damage, all 400Ah are usable. The old bank was 230Ah at 24V but only ~115Ah usable; the new bank is 400Ah usable. He doubled the number of batteries and nearly quadrupled real storage.
Charge speed. Lithium can be charged about five times faster than lead-acid. On a sunny day or with the generator running, the bank takes charge much more quickly, which matters in winter when sun windows are short.
Cycle life. Battle Born rates these cells for 3,000-5,000 cycles — roughly ten years of daily charge-and-discharge. Martin notes that his bank, charged and drained daily, is rated for about ten years and will very likely last longer because it will not be cycled that hard every single day.
Physical handling and safety. Each 100Ah 12V cell weighs about 31 pounds — half the weight of a comparable lead-acid battery — and Martin demonstrates picking one up one-handed out of its protective bag. There is no liquid inside, so there is nothing to spill, no acid to leak, no upright-only mounting. You can mount these on any side and not worry about corrosion terminals the way you do with flooded cells.
The same trade-offs drive every decision in our LiFePO4 battery line — which is why a lead-to-lithium swap like this is the single highest-impact upgrade most off-grid systems can make.
The video is careful about the order of operations, and you should be too. First, disconnect the solar panels so no power flows into the shed — Martin unplugs the panel pairs one and two. Then power down the whole system, which means losing the lights mid-video; he runs a battery-powered work light so the camera keeps working. Only then does he unbolt the old inverter from the wall and clear the boards.
Three rules to take away: never pull batteries while panels are live, never skip the main disconnect, and always have a separate light source for the work. If you are upgrading your own shed, also wear insulated gloves and keep a fire extinguisher within reach — this is DC energy, and a short across a 24V lithium bank is no joke. Fusing is non-negotiable: the new build uses a 250A main fuse on the positive side, and each charge controller is fused too.
The batteries are 12-volt cells, and the inverter and charge controllers are 24-volt, so the bank must be wired as series pairs paralleled together. The pattern Martin demonstrates is the standard one: pair two batteries in series (positive-to-negative) to make 24V, do that four times, then parallel all four pairs. In practice that means connecting battery-to-battery diagonally so the load sees equal resistance across all cells — the arrangement he calls "the most efficient use of wiring."
The result is a 24V, 400Ah bank: eight batteries, four series pairs, all cells working together. Getting the cabling right is the whole job, and the video spends real time on it for a reason — bad connections and undersized cable are the leading causes of off-grid fires.
Martin uses a flexible welding-style battery cable and crimp connectors sized to the cable gauge (double-lock connectors for double-gauge cable). His technique is worth copying: strip the insulation to the right length, slip the connector on until it seats against the flare, put the crimp tool on something solid like a stump, and hit it with a hammer until you hear the pitch change — that sound change tells you the crimp has compressed fully and locked the wire in. He also pre-bends short cables into a U-shape before crimping the second end, because bending after the connector is on is much harder.
Two lessons apply to any battery build: match the connector size to the cable, and do not reuse a crimp that has not fully compressed. A loose crimp is a hot spot that will eventually fail. Use a proper cable lug, heat-shrink or adhesive-lined sleeve over the joint, and torque the terminal bolts properly.
The layout in the shed is functional as well as tidy. The inverter sits below the battery shelf, and Martin points out that the inverter radiates heat all the time — 24 hours a day on a homestead. That rising heat passes through the gap behind the batteries, which is exactly what he wants: Battle Born's minimum operating temperature is -4°F, and in northern Idaho winters can drop below that. The inverter's waste heat keeps the bank warm enough to operate, and if a colder stretch comes, enclosing that space traps the heat and keeps the batteries toasty. It is a smart use of what would otherwise be wasted heat.
If you build a similar compartment, remember the same principle in reverse in summer: lithium does not like sustained high heat either, so leave airflow above the bank for the warm season.
The new system runs two Victron charge controllers — a 50A unit for one array and a 70A unit for the other. Both come pre-programmed for the Battle Born batteries, which removes the most common installation error: setting charge voltages wrong. They have no on-board display; instead they connect by Bluetooth to a phone app, where Martin can see charging watts, battery voltage, state of charge and power flowing in or out — from inside the cabin, not from the shed.
The battery monitor is a Victron shunt-based unit: all the negative cables pass through the shunt, and a small display (or the app) reads the bank. The positive side runs through the 250A main fuse before connecting to the inverter. In the video the small controller was producing about 140W at 62.9V on the cloudy day, the big controller 305W at 76V, and the app showed 166W flowing into the battery — meaning the panels were covering the house load and still charging. With the generator running, the same bank accepted about 1,000W of charge and the app showed the state of charge climbing from 57% to 59% within minutes.
The video's real-world results are the most useful part of the whole build. Through several days of rain and heavy cloud, with the house running off the bank, the system stayed healthy: solar covered the daytime loads and pushed surplus into the batteries; the generator topped the bank up when needed, and the app made every number visible in real time. On the worst day shown, the shed was producing a few hundred watts between clouds — yet the bank carried the cabin through, which is exactly what four times the usable capacity buys you: not more sun, but more days between sunny days.
Martin also adds solar: the original six panels plus four more added in this build total about 3,200W of array on Unistrut racking. That combination — a big LiFePO4 bank plus enough array — is the reason his cabin can run through weather like that.
If you are running a lead-acid bank at 24V and hitting the same wall, this build is a proven template. Budget reality check: eight premium 100Ah cells are a meaningful investment, but you nearly quadruple usable capacity and gain five-times-faster charging and roughly ten years of cycle life. Martin's own summary is honest: whether it is an RV, a cabin, or even a trolling-motor boat, if you currently rely on lead-acid, lithium does the same job better and more efficiently — and with proper wiring, the swap is a weekend project.
If you would rather buy a matched bank than assemble eight individual cells, the same engineering goes into every LiFePO4 drop-in battery we build: 100% usable capacity, 6,000+ cycle life, built-in BMS, and battery-to-battery wiring that is designed for the job. Tell us your voltage, capacity and footprint and we will size the pack to your shed, RV or boat.
Dajiu Energy is a Chinese manufacturer building LiFePO4 batteries for RVs, homes, golf carts and portable applications since 2017. Our product range covers LiFePO4 drop-in replacement batteries, EV and golf cart batteries, wall-mounted home storage, portable power stations, commercial energy storage and battery swap cabinets — explore the full lineup in our product center, or browse more buying guides. Tell us your voltage, capacity and size, and we'll engineer the pack to hit it.
Source video: Martin Johnson — Off Grid Living — "EASIEST Off Grid Solar Power System Battery Bank" (youtube.com/watch?v=lGs0VPKM1jU). Comment excerpts are quoted verbatim from the video's top comments; answers are Dajiu Energy's own. Build details and measured figures are transcribed from the video.
Tell us your voltage, capacity, size and application. We will get back to you with a professional quote and technical spec as soon as possible.