Ten Years Powering a Claim: Wet Cells to AGM to Lithium
Ten years of running off-grid power on gold claims — what wet lead-acid actually cost me, what AGM fixed, what LiFePO4 changed, and how to size a bank for a weekend or a season.
Table of Contents
- What Actually Draws Power on a Claim
- The Only Two Formulas You Need
- Wet Cells: Where Everybody Starts
- AGM: Sealed, Civilized, Still Lead
- LiFePO4: The Change That Actually Mattered
- Inverters and Controllers: What I Run and What I Regret
- Fixed, Portable, and Mobile: Three Different Animals
- Sizing a Weekend
- Sizing a Longer Stay
- If You Don't Want to Build a Bank
- What I'd Tell Someone Starting Today
Ten Years Powering a Claim: Wet Cells to AGM to Lithium
I've been chasing gold for 22 years. For the last ten of those I've also been the guy in camp everybody comes to when their detector won't hold a charge, their pump quits at 2pm, or their brand-new inverter is beeping at them in the dark. Somewhere along the way, keeping power alive on a claim turned into its own hobby, and I've owned enough of it — wet cells, AGM, lithium, inverters good and bad, fixed banks, portable boxes, and trailer-mounted solar generators — to have opinions I can actually back up.
This is not a van-life guide and it isn't a home-backup guide. Those people plug in at a campground or sit next to a service panel. We're talking about ground where the nearest outlet is forty minutes of dirt road away, where the load is a pump and a pile of battery chargers, and where running out of power at noon means you shut down the highbanker and go sit in the shade.
Here's the honest version of what ten years taught me.
What Actually Draws Power on a Claim
Ask a prospector what he needs to run and he'll say "a couple chargers." Then you watch him for a day and count what's really plugged in:
Two reasons people underestimate all this. First, they think in amps instead of amp-hours — "it's only a 5-amp pump" is meaningless until you multiply by how many hours it runs. Second, they size for the good day and not the bad one. The bad day is overcast, you ran the pump longer than you meant to because you hit a good streak, and you forgot to shut the inverter off overnight.
The Only Two Formulas You Need
You do not need to understand battery chemistry to size a system. You need two lines of arithmetic and the honesty to use real numbers.
Watt-hours = Amp-hours × Volts
A 12V 200Ah lithium battery is not "200." At the 12.8V nominal of LiFePO4 that's 200 × 12.8 = 2,560 watt-hours. That's exactly why the two 12V 200Ah packs I run are labeled 2560Wh — the label is just the multiplication done for you.
Same math scales up. A 48V 100Ah LiFePO4 battery sits at 51.2V nominal, so 100 × 51.2 = 5,120Wh. Two of them in parallel is 10,240Wh of nameplate storage.
Runtime in hours = usable watt-hours ÷ load in watts
The word doing all the work there is usable. Nameplate capacity is not what you get to spend:
So a 100Ah AGM at 12V looks like 1,280Wh on paper, is about 640Wh in practice, and is maybe 550Wh by the time it's gone through an inverter. The same-size LiFePO4 gives you roughly 1,100Wh usable. That gap is the entire story of the last decade, and it's why the rest of this guide reads the way it does.
Wet Cells: Where Everybody Starts
Ten years ago I was running flooded lead-acid, because that's what there was and that's what was cheap. Wet cells work. They are also the most demanding batteries I have ever owned, and everything that made them miserable was structural to the chemistry, not bad luck:
The biggest wet bank I've owned was 24 × 2V 468Ah GHB industrial cells wired to 48V — 468Ah at 48V, somewhere in the neighborhood of 22kWh of storage. That is a serious pile of lead and it did serious work. How that bank ended is not a battery story at all. It's an inverter story, and it's further down this page.
What Actually Kills Them
Nobody wants to hear this, because it isn't dramatic. There was no single catastrophic event. What kills wet cells is sitting, and being run too low.
A flooded cell that gets pulled down deep, or gets left sitting discharged, comes back a little less each time. That's the whole mechanism. It isn't a failure you can point at and photograph — it's a slow subtraction. You charge it, it comes back a little less, and one day the bank that used to get you through the night doesn't, and you realize it stopped being the bank you bought some months ago without ever bothering to tell you.
Out here, heat is the accelerant. Heat plus drawdown is what finishes them in the desert. A bank that might have limped along for years somewhere mild gets used up a lot faster in a Nevada summer, and the two effects compound: heat degrades the cell, the degraded cell sags harder under the same load, and sagging harder means you're pulling it deeper to do the same job tomorrow.
Where Wet Cells Still Earn Their Keep
I want to be careful here, because the easy version of this story is "lithium won, throw your lead in the scrap pile," and that is not what I actually believe.
I still run wet cells on purpose, for winter work and smaller jobs. The clearest example in my own operation is powered water over a shaker table on 12V. A wet cell runs that all day. It goes on charge overnight, and it is full again the next morning. That is a duty cycle flooded lead is genuinely good at: a moderate steady draw, a complete recharge every single night, and no expectation that the battery will sit half-empty for a week waiting on you.
Notice that this is the exact inverse of the pattern that kills them. The jobs where wet cells stay healthy are the jobs where they never sit low. The jobs where they die are big loads, deep discharges, days between full charges, and heat. If your work looks like the first list, a wet cell is a perfectly rational thing to own. If it looks like the second, you are buying a consumable and you should go in knowing it.
AGM: Sealed, Civilized, Still Lead
AGM was the middle chapter, and it fixed the two problems that made wet cells genuinely unpleasant in the field: no watering, and no spilling. Absorbed glass mat means the electrolyte is held in the mat instead of sloshing around, so the battery is sealed, can be mounted at odd angles, and can live in a closed box on a trailer without you thinking about it.
What AGM did not fix is the part that actually matters: it is still lead. Same roughly-50% usable capacity, same weight, same dislike of deep cycling, same slow charge acceptance near the top of the curve. You paid more for convenience and got zero more energy.
My own AGM experience is tied up with Renogy — I ran Renogy AGM batteries alongside Renogy inverters, and my verdict on that gear is simply not so good. The inverter half of that story I can tell in full, and I do, below. On the batteries themselves I'm not going to manufacture a failure narrative I'd have to invent. It's a brand I used and didn't rate.
If you are shopping today and someone tries to sell you an AGM bank for a prospecting camp, the honest question to ask them is: what does this do for me that lithium doesn't, other than cost less up front? On price per usable watt-hour over the life of the bank, lead lost that argument years ago.
LiFePO4: The Change That Actually Mattered
Lithium iron phosphate is the reason I stopped thinking about batteries as a problem. What changed, concretely:
My lithium is now spread across sizes on purpose rather than as one big bank: a pair of 48V 100Ah packs for the main system, two 12V 200Ah (2560Wh) packs, an assortment of 12V 100/200/300Ah and 48V 50/100Ah batteries, plus small stuff — two GOLDENMATE 12V 10Ah and a NERMAK 12V 16Ah — for the little jobs where dragging out a big pack is silly.
That spread is the practical lesson. On a claim you rarely need one giant bank; you need the right-sized battery for the job in front of you, and lithium is light enough that carrying two purpose-sized packs beats carrying one heavy compromise.
What the Dual 48V Bank Does, and Where It Stops
The two 48V 100Ah packs in parallel are the main system, and I'll give them the review they've earned: they perform very well. Pump duty, chargers, camp loads, tools, days on end — the bank doesn't complain and I don't think about it.
There is exactly one place it stops, and it's worth stating plainly because it's the case every solar sales page skates past: running air conditioning overnight in peak summer. In the Nevada desert that is a different order of load from everything else in this guide combined, and the bank will not carry it through to morning. So it doesn't. On those nights I run a generator, about five hours, and that covers it.
I'd rather say that out loud than sell anybody the solar-only fantasy. My system is solar-primary with a generator in reserve, and on the hottest nights of the year the generator is not optional equipment.
Two Cautions, and What I Do About the Cold
Two honest cautions about LiFePO4, which are chemistry facts and not brand complaints:
On the cold one, I buy around it. For some jobs I deliberately spec low-temperature-capable LiFePO4 packs, because people hear "desert" and picture August. Desert winters get genuinely cold, and a pack that refuses to take a charge on a January morning is a pack that isn't working that day. If you prospect through the winter, treat low-temp capability as a specification you shop for, not a bonus you hope is in there.
Inverters and Controllers: What I Run and What I Regret
Batteries get all the attention and inverters cause most of the failures. Here's my scorecard, stated plainly, with no supporting drama invented.
PowMr: good for me. That's my verdict after using their gear, and it's why the centerpiece of my system is a PowMr 5000W hybrid solar inverter — 48V in, 110/120V out, with an 80A MPPT charge controller built in and a 5500W maximum PV input. An all-in-one like that removes an entire category of problems: one box, one set of settings, one thing to wire, and the solar controller and the inverter already agree with each other about the battery.
I also run a PowMr 60A MPPT charge controller (12/24/36/48V selectable) and an iSunergy 80A 180V MPPT controller. The 180V input rating on that iSunergy is the interesting number — a high input-voltage ceiling is what lets you wire panels in series into a long string, which means less voltage drop over a long run from where the sun is to where the camp is. On a claim that's not a spec-sheet detail, it's the difference between putting panels where they work and putting them where the cable reaches.
Renogy: The 3500W Combo That Took the Bank With It
Renogy: junk. The unit was a Renogy inverter/controller combo — a 3500W pure sine wave inverter, 48V to 110V — and that verdict is stated plainly, with the whole story attached, not a rating I'm leaving unexplained.
The inverter was mounted in a box outside. In the Nevada desert, it rusted.
Sit with that for a second, because it's the part that tells you everything. It makes very little sense for something to rust in that little humidity. There is barely any moisture out there to work with. If a piece of equipment manages to find enough of it to corrode through a Nevada summer, that is not an environment problem. That is a statement about the quality of the material it was built out of.
The rust wasn't what killed it, though. What killed it was the DC input shorting. Everything died at once. And because a short on the DC side does not stay politely inside the inverter, it took the entire battery bank into a full short with it — that 24-cell, 2V 468Ah GHB wet bank, 48V and roughly 22kWh, gone along with the box that was supposed to be protecting it.
A very expensive failure.
That is the whole reason I'm as blunt as I am about inverter quality in this guide. The battery bank is usually the most expensive single thing in an off-grid system, and the inverter is the component standing between it and a fault. Buying a cheap inverter to protect an expensive bank is a bet you only have to lose once.
Sizing an Inverter, Generally
I also keep a 3000W (6000W peak) 12V to 110/120V inverter around. Note the two numbers: continuous and peak. That distinction is the single most useful thing to understand about inverter shopping, and it's general electrical fact, not opinion:
One more general rule worth stating: pure sine wave, always. Modified sine is cheaper and will run a light bulb, but battery chargers, anything with a switching supply, and any motor speed control would all rather have a clean waveform.
Fixed, Portable, and Mobile: Three Different Animals
I've run all three form factors, and they solve genuinely different problems.
Fixed means a permanent bank, usually at a base camp or shop, with panels mounted where they'll live. Advantages: you can build big, you can wire it properly once, you don't carry it. Disadvantage: it is where it is. A fixed system is right when you work the same ground repeatedly and have somewhere secure to leave it.
Portable means a battery box or two you can move by hand — a pack, an inverter, and a folding panel. This is the form factor most prospectors actually need, and lithium is what made it viable. It's the difference between "the power is at camp" and "the power is where I'm digging."
Mobile generating station is a whole system that travels as a unit. For me that's DC Solar mobile solar generators — trailer-mounted units with the panels, bank and electronics integrated. I bought ten of them, used, at auction, and I still run them. What a trailer buys you over a portable box is scale without setup: you tow it in, level it, and you have a real system on your claim in minutes rather than an afternoon of unfolding and wiring. What it costs you is access — a trailer only goes where a trailer goes, and plenty of good ground doesn't have a road to it.
What's Actually on a DC Solar Trailer, and What I Changed
These units come up at auction regularly and people ask me about them constantly, so here's the real answer from somebody who owns ten of them.
The array. Each trailer carries 10 × 300W panels — a 3kW array. I'd have liked more watts per panel, and I looked hard at 400W panels, but going to 400s would have meant fabricating new brackets to mount them. Given the choice again I'd rather have 365W panels: more output than stock, and they go on the mounting I already have instead of the mounting I'd have to build. That trade — a slightly smaller panel that fits versus a bigger one that turns into a fabrication project — is worth thinking through before you start ordering panels.
The batteries. I kept whichever of the original batteries were still usable, and everything else I swapped for 48V 100Ah LiFePO4 packs in parallel. That's the same chemistry and the same pack size as my main system, which is deliberate: one spare fits everything.
The electronics, and this is the part nobody warns auction buyers about. I upgraded the inverter and the charge controller on every single one of them. Most of these trailers are old enough that firmware updates stopped coming, and equipment that stopped receiving updates simply cannot keep up with newer battery technology. The practical consequence is blunt: on these units, changing the batteries means changing the inverter too. If you're pricing an auction trailer, price it as batteries plus inverter plus controller — not as a working system with tired batteries in it. That's the mistake I'd steer people away from.
How many trailers for what. Rough deployment guide, from actually doing it:
And the practical answer for most people who work more than one spot is both ends of the range: something mobile or fixed that holds the bulk capacity and does the heavy charging, plus a small portable pack that goes to the dig.
Sizing a Weekend
Here's the method, worked. The numbers below are example figures chosen to show the arithmetic — they are not measurements off my gear. Substitute the actual nameplate ratings from your own equipment, because pumps in particular vary wildly.
Start by listing every load as watts × hours per day:
That totals roughly 760Wh per day — and notice that the inverter you forgot to switch off is the second-largest item on the list. Shut it off and you're at 560Wh.
Now convert to a bank. For a two-night weekend with no charging at all, you need 2 × 760 = 1,520Wh usable. Divide by the usable fraction for your chemistry:
Same weekend. One battery you can carry with one hand, or two you can't. That comparison is why I stopped buying lead for anything that has to carry a camp.
Add margin deliberately. I'd size a weekend bank at 1.5× the calculated number. Cloud, a colder-than-expected night, a pump that runs longer because the ground is paying — the margin is not waste, it's the difference between finishing the day and packing up early.
Sizing a Longer Stay
Past about two nights, the question changes. You stop sizing the battery and start sizing the charging, because on a long stay the bank is just a buffer between today's sun and tonight's loads.
The rule is simple: your daily charge input has to meet or beat your daily consumption, with enough battery in the middle to carry you through the worst stretch of bad weather you're willing to plan for.
Solar math, in the same spirit as the battery math:
Three things I'd tell anyone planning a long stay:
For a genuinely long stay — a week or more of steady digging — the honest answer for most people is a hybrid setup: solar as primary, a large bank as buffer, and a generator kept in reserve for the stretch that no amount of panel makes up for. And that isn't a hedge I offer other people while quietly running something purer myself. As I said further up, my own system is solar-primary with a generator, and in peak summer that generator runs about five hours a night to keep air conditioning going. Grey days and hot nights are the two cases where solar alone doesn't finish the job, and pretending otherwise is how people end up sitting on a dead bank with no plan B.
If You Don't Want to Build a Bank
Everything above assumes you're willing to assemble components. Plenty of prospectors aren't, and there's no shame in that — you came out here to find gold, not to crimp lugs.
That's the market the sealed all-in-one units serve: Jackery, EcoFlow, Bluetti and the rest. I have never owned one, so I won't pretend to review them. What I can do is tell you what the published specifications mean for a claim, and how to read them.
By way of published examples: Bluetti rates the AC200L at 2,048Wh with a 2,400W AC output; EcoFlow rates the Delta 2 at 1,024Wh with 1,800W AC; Jackery rates the Explorer 1000 v2 at 1,070Wh with 1,500W AC. Model lines change constantly, so treat those as illustrations of the class and check the current spec sheet before you buy anything.
Read a sealed unit exactly the way you'd read a bank you built:
Where they genuinely fit: one person, a detector and phones, weekend trips, and a strong preference for zero wiring. Where they struggle: multi-day pump duty, expanding capacity later, and repairability — when a sealed unit's electronics fail, you generally have a warranty claim rather than a replaceable part. My system is components precisely because I can swap a controller or an inverter in the field and keep working. Given that one inverter failure has already cost me an entire battery bank, being able to replace a single box is not a small thing.
What I'd Tell Someone Starting Today
Twenty-two years of prospecting, ten of them fussing with power, and the summary is short. Lead taught me that a battery you have to baby is a battery that's quietly leaving you a little at a time. AGM taught me that convenience isn't capacity. One bad inverter taught me that the cheapest component in the system gets to decide the fate of the most expensive one. And lithium finally made the power boring — which, on a claim, is the highest compliment there is. I still have wet cells doing honest work on a shaker table through the winter, and I still fire up a generator on the hottest nights of the year. But the thing that decides whether I finish the day is the ground now, not the bank.
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