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has changed dramatically in the last few years, and honestly, most of the advice you'll find online is already outdated.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 anymore.

Prices have dropped enough that we recommend 280Ah even if you think you'll need less — the cost difference from a smaller battery is minimal, and the extra buffer for cloudy weather and future devices is worth a lot of peace of mind.

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 most people, the answer is 280Ah — and the reason is simple: the cost bump from a smaller battery isn't that big, but the extra buffer is worth a lot of peace of mind.

For reference:

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

Why 280Ah for almost everyone

A budget 200Ah pack costs $280-380. A 280Ah pack costs $330-400. That's roughly $20-50 more for 40% more capacity. The extra headroom means you can weather cloudy days without stressing, add devices later without upgrading your battery, and generally not think about power management as much.

Even if you're only doing weekend trips now, your usage tends to grow — you add a fridge, start taking longer trips, maybe work from the van occasionally. Starting with 280Ah means you won't outgrow your battery as quickly.

The 280Ah advantage in detail

Winter and cloudy days

Your 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.

Room to grow

Your power needs tend to grow over time. A fridge adds ~400Wh/day, Starlink adds ~250Wh/day, a diesel heater adds ~150Wh/day. 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 — installation is the same as a 200Ah battery. Same physical mounting, same wiring complexity. Only ~20 lbs heavier (~70 lbs vs ~50 lbs).

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, starting with one 280Ah battery makes more sense than buying two upfront. It's simpler, lighter, and cheaper — and you may find it's all you need.

That said, it's smart to design your layout with space and wiring for a second battery, so you can add one later if you need it. Adding a battery in parallel is straightforward, but only if you've left room for it.

Example Build

What a 3-battery full-timer bank looks like

An off-grid build with three 280Ah batteries in parallel — induction cooking, Starlink, diesel heat, and daily showers. Hover the wires to see gauge and fuse sizes for the high-current bank.

2,274 Wh/day2 batteries · 800W solar · 60A DC-DC$2,735 components
Beta

Educational estimates only — not a substitute for a licensed electrician. Verify against ABYC E-11 and manufacturer specs before installing. See full disclaimer.

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Customize in the planner

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 very high-power inverters (5000W+) or very large battery banks (800Ah+), but that's not most people. A 3000W inverter works perfectly fine on 12V. 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 $800+ on a premium 280Ah battery instead of $400 on an Eco-Worthy 280Ah?" Here's the reality at the same capacity: budget brands use the same EVE and CATL prismatic cells as Battle Born and Renogy, and independent teardowns and capacity tests have consistently rated Eco-Worthy on par with the premium brands — sometimes better. The premium is mostly the warranty, the support, and the sticker.

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.

BMS specs — matching your battery to your inverter

This is the single most-ignored spec on a battery product page, and the one most likely to leave you with a tripped BMS every time your inverter tries to start something. Every LiFePO4 pack has a BMS with two current ratings: continuous (what it can deliver constantly) and surge / peak (what it can handle for a few seconds). Both matter.

The 3000W-on-100A-BMS trap

A 3000W inverter at full load pulls 3000W ÷ 12V ≈ 250A continuous from the battery. When a compressor, induction cooktop, or power tool kicks on, the surge can briefly hit 400-500A. A battery with a 100A BMS will trip instantly — and the cheapest 200Ah packs across budget brands (LiTime 200Ah standard, Redodo 200Ah, Vevor 200Ah) all ship with 100A BMSs.

Symptoms: inverter shuts off under load, battery disappears from Bluetooth for a few seconds, resets fine. That's the BMS cutting out, not the inverter.

Sizing rule

BMS continuous amps ≥ (inverter continuous watts ÷ 12V) × 1.25

The 1.25 multiplier is margin for inverter inefficiency (pure sine wave inverters are ~85-90% efficient) plus headroom so the BMS isn't running at its limit 24/7.

  • 2000W inverter → ≥ 210A BMS (one 200A-BMS pack is fine — this is the right pairing for a single Eco-Worthy 280Ah)
  • 3000W inverter → ≥ 310A BMS (need a 300A pack or two 200A-BMS packs in parallel)
  • 5000W inverter → ≥ 520A BMS (you're in two-batteries-or-24V territory)

Working the rule backwards: if you already know your battery's BMS, the largest inverter it can support continuously is roughly BMS_A × 12V ÷ 1.25. A 200A-BMS pack maxes out around 1,920W ≈ 2000W continuous. A 150A-BMS pack (Vevor 280Ah) maxes out around 1,440W — closer to a 1500W inverter than a 2000W.

Real specs on common 12V packs

Every spec below is from the manufacturer's current product page. Anything marked "not published" is a red flag — a brand that won't tell you the surge rating is hoping you won't notice when it trips.

BatteryContinuousSurge
LiTime 12V 200Ah (standard)100A400A @ 1s
LiTime 12V 200Ah Plus200A400A @ 5s, 600A @ 1s
Battle Born 100Ah (standard)100A200A @ 30s, >500A @ 0.5s
Battle Born GC3 270Ah300A500A @ 30s
Renogy 12V 200Ah Core200A400A @ 10s
Eco-Worthy 12V 280Ah200ANot published
Vevor 12V 200Ah100ANot published
Vevor 12V 280Ah150ANot published
Redodo 12V 200Ah (standard)100ANot published
EG4 LifePower4 12V 400Ah200ANot published

The Eco-Worthy 280Ah ceiling: 200A continuous

The Eco-Worthy 12V 280Ah pack we recommend ships with a 200A continuous BMS. That's plenty for everything DC in a van — fridge, lights, water pump, fan, even a 30A DC-DC charger pulling at the same time — but it sets a hard ceiling on the AC side: the BMS will trip if the inverter ever sustains more than ~2,400W of pull (200A × 12V), and it leaves no headroom for a compressor or induction surge stacked on top.

That's why the recommended single-battery system in this guide pairs the Eco-Worthy 280Ah with a 2000W inverter, not a 3000W. A 2000W inverter at full load draws ~190A continuous; the 200A BMS has just enough headroom to ride out a brief surge without tripping protection.

Want a 3000W inverter? Add a second Eco-Worthy 280Ah pack in parallel. That doubles the bank to ~400A combined BMS, which clears the 310A target with margin for compressor and induction surges hitting at the same time.

Parallel packs stack

BMS ratings roughly sum in parallel. Two 200A-BMS packs (a pair of Eco-Worthy 280Ah, LiTime 200Ah Plus, or Renogy 200Ah Core units) give you ~400A continuous — comfortably above the 310A you need for a 3000W inverter, and cheaper than the single 300A-BMS Battle Born GC3.

If you're pairing with a Vevor 3000W inverter and want to keep it in-brand, two Vevor 12V 280Ah packs in parallel land at ~300A combined — right at the line for a 3000W inverter. It'll handle normal loads, but you're not leaving much margin for a compressor starting at the same time as an induction cooktop. Just make sure both batteries are the same chemistry, rated capacity, and age — mismatched packs drift out of balance and one ends up carrying most of the load.

Red flags

  • No surge rating published. If the spec sheet only lists continuous, assume the surge is barely higher than continuous — and definitely not enough for a 3000W inverter.
  • Surge listed without a duration ("400A peak" with no seconds). A 400A pulse for 100ms is useless for a compressor start; you need at least 1-5 seconds.
  • "200A BMS" batteries that are actually 100A BMS with a label — check the BMS model number on the spec sheet or tear-down videos.

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 (class-T)

The main fuse on a LiFePO4 bank has to be a class-T, mounted within 7 inches of battery positive, sized to protect the cable that leaves it. ANL and MEGA fuses can fail to clear a lithium short — a healthy 280Ah pack can dump more than 5,000A into a dead short, and only class-T has the 20,000A AIC to interrupt that cleanly. For the Eco-Worthy 280Ah + 2000W inverter pairing in this guide, a 250A class-T on 2/0 AWG is the spec; for a two-pack parallel bank feeding a 3000W inverter, step up to a 300A class-T on 4/0 AWG. The fuses and breakers page has the full breakdown — including why ANL fuses on a lithium main are one of the most common budget-build mistakes.

Proper wire sizing

Size the battery-to-bus cable for the BMS rating, not for the load. A single Eco-Worthy 280Ah pack with a 200A BMS wants 2/0 AWG minimum (~265A ABYC ampacity at 105°C). Two packs in parallel feeding a 3000W inverter wants 4/0 AWG (~360A) — the inverter alone draws ~250A continuous and surges past 400A. Thinner wire heats under load, drops voltage, and trips the inverter before the BMS does. The wiring and connections page walks the ampacity-vs-voltage-drop math and the ABYC sizing tables in detail.

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.

Cold weather & winter operation

LiFePO4 is picky about cold. Not as picky as the internet makes it sound — but picky enough that if you park in sub-freezing temps for days, you need a plan.

The one rule that matters

Never charge a LiFePO4 battery below 0°C / 32°F. Forcing charge current into cold cells causes lithium plating on the anodes — it's permanent, cumulative damage that reduces capacity and can eventually short the cell internally.

Discharging cold is fine. LFP cells deliver power down to about -20°C / -4°F at reduced capacity. Your fridge, heater, and lights keep working when it's freezing outside — you just can't replenish the battery from solar or DC-DC until things warm up.

Capacity loss at low temps

A 100Ah pack delivers roughly 80Ah at 0°C / 32°F and ~70Ah at -18°C / 0°F — about 15-30% less usable capacity in winter. Not a crisis, but worth accounting for when you're planning winter trips.

Three ways to handle it

1. Self-heating batteries

Internal heat pads powered by the charge source itself — they engage automatically when cell temp drops below freezing and charge current is present. You do nothing; the battery handles it.

  • LiTime 12V 100Ah Self-Heating: 100W heater. Warms from -10°C to charging temp in 30-60 min, from -20°C in 70-100 min. Activates below ~5°C / 41°F.
  • LiTime 12V 200Ah Plus Self-Heating: 150W heater. 70-90 min warm-up from -10°C.
  • Battle Born GC3 Heated (BBGC3H, 270Ah): Proprietary low-draw internal heater; Battle Born doesn't publish exact wattage.
  • Renogy 12V 200Ah Pro Smart: Self-heating variant available.

Expect to pay a $75-150 premium over the non-heated version. Worth it if you'll park in sub-freezing temps regularly. Note: Vevor doesn't sell a self-heating LFP variant, so for this specific need you're shopping LiTime, Battle Born, or Renogy.

2. External silicone heat pads

Adhesive-backed pads that wrap around the battery case. Common sizes draw 15-30W at 12V (~1.25-2.5A). Wire through a thermostat so they only run below 5°C / 41°F, otherwise you're burning solar for no reason.

Cheaper than a heated battery (~$20-40 per pad) and retrofits an existing pack. Downside: you're adding another failure point and the pad runs off battery power even when you're not charging.

3. Don't charge when cold

Any decent BMS has a low-temp charge cutoff — it simply refuses incoming current when the pack is below 0°C. Your solar panels produce, your DC-DC charger tries to push current, and the battery just says no. No damage, no drama, but also no charging until it warms up.

Works fine if you drive daily (cabin heat plus the battery's own I²R self-warming from charge current keeps cells above freezing) or if your interior stays above freezing while you're living in it. A running diesel or propane heater keeps the cabin warm, which keeps the battery warm.

Practical guidance

  • Full-timer who drives most days: Skip heated batteries. Alternator charging keeps the pack warm, and your interior stays above freezing while you're living in it.
  • Weekend boondocker in winter: Get a self-heating battery or add external pads. Your van sits parked for days in the cold, and solar that can't charge is solar you paid for and can't use.
  • Snowbird heading south Nov-March: Skip it. You'll never see freezing temps for more than a travel day.
  • Ski-bum or winter-only rig: Heated batteries are not optional. Assume multiple days of sub-zero and plan accordingly.

Verify before you buy

Not every "budget LiFePO4" has a low-temp charge cutoff. The BMS protects the cells from chemical damage, and some ultra-cheap packs skimp on it. Check the spec sheet for "low-temperature protection" or "charging temperature cutoff." If it's not there, assume it doesn't exist and move on.

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
Add battery to your build plan:

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.