Batteries

Battery technology has changed dramatically in the last few years, and honestly, most of the advice you'll find online is already outdated. If you're reading forum posts or watching YouTube videos from even 2-3 years ago, the battery recommendations are going to steer you wrong.

Bottom Line Up Front

Get LiFePO4 (lithium iron phosphate) batteries from a reputable budget brand like Eco-Worthy. There's no good reason to choose anything else in 2025.

Why LiFePO4 is a no-brainer now

A few years ago, LiFePO4 batteries cost $800-1,200 per 100Ah — 4x the price of AGM. That made it a real debate. Not anymore.

LiFePO4 now costs about the same as AGM — and gives you nearly 2x the usable capacity.

AGM 100Ah (50Ah usable)
$150-250
LiFePO4 100Ah (90Ah usable)
$150-250

Chinese manufacturers flooded the market with quality LiFePO4 batteries using the same EVE and CATL cells as premium brands. A 280Ah LiFePO4 battery now costs $330-400 — the math is overwhelmingly in favor of lithium.

Why LiFePO4 specifically?

There are several lithium chemistries. Here's why LiFePO4 (lithium iron phosphate) is the right choice for vans:

  • Safety: Most stable lithium chemistry — won't catch fire or explode under normal conditions. This matters in a vehicle where things bounce around and get hot.
  • Lifespan: 3,000-5,000+ cycles at 80% depth of discharge. That's 8-13+ years of daily use, compared to 1-2 years for AGM at the same usage.
  • Usable capacity: Use 80-90% of rated capacity vs. only 50% for AGM. A 280Ah LiFePO4 gives you ~250Ah usable.
  • Weight: A 280Ah LiFePO4 weighs ~70 lbs. Getting 280Ah usable from AGM would require ~560Ah rated capacity at ~350 lbs.
  • Voltage stability: Maintains consistent voltage throughout discharge. Your devices get stable power until the battery is nearly empty.
  • Temperature tolerance: Works well in a wide range. Many have built-in heating for cold weather charging.

Battery sizing - why 280Ah is the sweet spot

Okay, you're convinced on LiFePO4. How much capacity do you actually need?

For reference:

  • 100Ah = 1,280Wh (at 12.8V nominal)
  • 200Ah = 2,560Wh
  • 280Ah = 3,584Wh
  • 300Ah = 3,840Wh

Weekend warrior (Friday-Sunday trips)

  • 100-200Ah is probably fine
  • You're only out for 2-3 days, you can manage power consumption
Cost: $200-400

Extended trips (1-2 weeks at a time)

  • 200-300Ah gives you good buffer
  • Covers cloudy days without stressing
Cost: $400-600

Full-time living or working remote

  • 280Ah minimum, ideally 300-400Ah
  • This is where my "280Ah baseline" recommendation comes in
Cost: $330-400 for 280Ah, $500-650 for 400Ah

Why 280Ah specifically for full-time builds?

Here's my reasoning for treating 280Ah as a baseline for anyone planning to use their van regularly or full-time:

The cost difference is minimal

200Ah LiFePO4:$400-500
280Ah LiFePO4:$330-400

You're talking about $50-100 more for 40% more capacity (depending on sales)

Winter and cloudy days

Remember from the power section - your 400W solar might only generate 800Wh per day in winter. If you're consuming 1,500Wh per day, you're running a 700Wh deficit.

With 200Ah (2,560Wh capacity)
3-4 days buffer
With 280Ah (3,584Wh capacity)
5-6 days buffer

That extra day or two of buffer means you can wait out a storm or a stretch of cloudy days without stressing about your battery level. You're not forced to drive somewhere just to charge up.

Flexibility for growth

When you first build your van, you might not have a fridge, or Starlink, or a diesel heater. But later you might add these. If you sized your battery for your initial usage, you're now undersized.

  • Fridge:+400Wh per day
  • Starlink:+250Wh per day
  • Diesel heater:+150Wh per day
  • Total:+800Wh per day you didn't plan for

With 280Ah, you have room to add devices without immediately needing to upgrade your battery.

It's still one battery

280Ah batteries come as a single unit - you're not wiring multiple batteries together. Installation is the same as a 200Ah battery. Same physical mounting, same wiring complexity. Only ~20 lbs heavier (~70 lbs vs ~50 lbs).

If you were choosing between 200Ah and 600Ah (two 300Ah batteries), that's a different conversation about weight and cost. But 200 vs 280? Just get the 280.

Can you go bigger?

Absolutely. Some people run 400Ah, 600Ah, or even more. This makes sense if:

  • You're running air conditioning (huge power draw)
  • You work from the van with high power needs (multiple monitors, desktop computer, etc.)
  • You want to run high-power cooking appliances daily
  • You rarely drive (so alternator charging isn't helping you)
  • You have massive solar to actually charge all that capacity

But for most people, 280-300Ah is the sweet spot. Beyond that, you're adding weight, cost, and complexity that might not actually improve your experience that much.

What about parallel vs. series configurations?

One 280Ah 12V battery vs. two 140Ah 12V batteries in parallel vs. 24V systems - this gets into the weeds, but here's the simple answer:

For most van builds: One 280Ah 12V battery is simplest

Why:

  • Single point of failure (not relying on multiple batteries staying balanced)
  • Simpler wiring (one battery, one set of cables)
  • Most van appliances are 12V (fridge, heater, lights, fans)
  • Most inverters and charge controllers are 12V

24V systems make sense if you're running high-power inverters (3000W+) or very large battery banks (800Ah+), but that's not most people. Stick with 12V and keep it simple.

Parallel batteries (connecting multiple 12V batteries together) can work fine, but now you have more connection points, batteries that can drift out of balance, and more complex installation. If you need more than 300Ah, sure, run two batteries in parallel. But if 280Ah will work, just get one battery and keep your life simple.

Brand recommendations

"Should I spend $1,200 on a Battle Born battery instead of $400 on an Eco-Worthy?" Here's the reality: budget brands use the same or similar cells, just without the markup.

Premium (Battle Born, Renogy)

100Ah: $1,200+
  • Excellent customer service and warranty claims
  • Bulletproof quality control
  • A nice sticker with an American brand name

Worth it for $100k+ professional builds. Overkill for DIY.

Budget (Eco-Worthy)

280Ah: $330-400
  • Same LiFePO4 cells, built-in BMS, Bluetooth monitoring
  • 3,000-5,000 cycle lifespan, 5-10 year warranties
  • Save $500-800+ vs premium for same capacity

The sweet spot for DIY van builds.

Battery features to look for

When shopping for your 280Ah LiFePO4 battery, look for:

  • Built-in BMS: Protects against overcharge, overdischarge, overcurrent, and short circuits. All reputable batteries have this, but verify.
  • Bluetooth monitoring: See state of charge, voltage, and current flow on your phone. Super helpful for troubleshooting.
  • Low-temperature cutoff (and ideally, heating): LiFePO4 batteries can't be charged below freezing. Good batteries prevent this; great ones have built-in heating. Worth it if you winter camp.
  • Series and parallel capability: Even if you're only buying one battery now, make sure it can connect to additional batteries later.
  • At least 5-year warranty and good reviews: Check Amazon or the manufacturer's site. 4+ stars with lots of reviews means it's probably fine.

Installation tips

LiFePO4 batteries are pretty simple to install, but a few tips:

Secure it well

These batteries are heavy (70 lbs). Use proper mounting brackets or a battery box. You don't want it sliding around or tipping over.

Good ventilation

LiFePO4 batteries don't off-gas like lead-acid, but they still can generate some heat. Don't seal them in an unventilated box.

Fuse protection

Put a fuse or circuit breaker on the positive terminal. Size it for your max expected draw (maybe 200A for most systems). This is critical for safety.

Proper wire sizing

Use thick wire (probably 2AWG or bigger) for the main battery connections. Don't cheap out here.

Battery monitor/shunt

Install a battery monitor (like a Victron SmartShunt, $150) so you can track exactly how much power is going in and out. Bluetooth monitoring built into the battery is good, but a separate shunt is better.

Accessible location

Don't bury your battery under your bed platform. You might need to access it for troubleshooting or to disconnect it.

My recommendation

For most van builds:

Get an Eco-Worthy 280Ah LiFePO4 battery (~$400). It has Bluetooth monitoring, a built-in BMS, and uses the same cells as batteries costing 3-4x more.

This gives you:

  • 3,584Wh of capacity — enough for full-time living
  • 5-6 days of buffer in winter conditions
  • 8-13+ year lifespan with daily cycling
  • Room to grow as you add devices
Link to our favorite battery

Skip Battle Born and other premium brands unless you're building a $100k+ professional van. For a DIY build, save the $500-800 and spend it on solar panels or just... camping.

Total cost for a great battery setup:

280Ah LiFePO4 battery:$400
Battery monitor/shunt:$150
Fuses and wiring:$100
Total:$650

This will give you 3,584Wh of capacity that will last 10+ years. Five years ago, this same capacity would have cost $3,000-4,000 and weighed three times as much.