That's right, we packaged modern Lithium Iron Phosphate power into a standard Group 41 battery case for a perfect fit under the driver's seat. Bring your camper into the modern day with a 100AH GoWesty LiFePo4 auxiliary battery!

Fits:
• This battery is a direct replacement for the VW-supplied auxiliary battery that was an option on Westfalia full campers and Wolfsburg Weekenders.
• It maximizes the space of the battery box underneath the driver's seat of all 1980-91 Vanagon models.
• Plus, it can be used in any location, in any vehicle as an auxiliary battery when connected to a LiFePo4-compatible charging system.

Note: Not for use as a starting battery. Does not include a hold-down bracket, bracket hardware, or battery terminal clamps and wiring. Those components must be sourced separately. See related items below.

Description: This 12.8V 100Ah LiFePO₄ battery is a compact, high-performance energy solution designed to fit neatly under the driver’s seat. Built with lithium iron phosphate (LiFePO₄) technology, it offers significantly longer cycle life, up to 2000 full charge/discharge cycles at 100% depth of discharge—compared to traditional lead-acid batteries.

Featuring an integrated Battery Management System (BMS), the battery is fully sealed, maintenance-free, and protected against overcharging, deep discharge, overheating, and short circuits. It also includes automatic low-voltage cutoff and internal cell balancing for optimal performance and safety.

Although rated at 100Ah, this lithium battery provides much greater usable capacity than its lead-acid counterparts—generally delivering up to 4x the effective runtime of a 50Ah lead-acid battery. With near-full usable capacity and faster, more efficient charging, it's ideal for off-grid, camper van, or auxiliary power systems.

These batteries can be combined for a larger power bank or installed individually right under your Vanagon driver's seat! If you're still not sold, we recommend reading this brilliant article by Victron Energy on their website.

Specs:
• Dimensions: 11" W x 6.75" H x 6.9" D
• Weight: 20.5lbs
• Operation Life Cycles: 2000 Cycles
• Expected Life: 10 Years
• Operation Temperature: -20-60°C (-4-122°F)
• Normal Charge Current: 20A
• Max Charge Current: 100A

Recommended related items: Renogy DC-DC Charger, DC-DC Charger Install Kit, and our battery hold-down kit for non-swivel seats. Add solar and you are all set!

Notice: This item is considered Hazardous Material (HAZMAT) by UPS, and may incur additional Hazmat fees.

IMPORTANT SHIPPING NOTE: Batteries ship domestically to the continental 48 states via UPS Ground shipping only (we CANNOT ship these batteries to Alaska or to Hawaii). NO expedited services (Next Day, 2nd Day, etc.) and no international shipping except to Canada via UPS Standard. Sorry, absolutely no exceptions.

100AH Battery Spec Sheet

There are countless, conflicting and confusing opinions on charging LiFePo4 batteries. We've boiled our advice down to some guidance that isn't too complicated:

• If you want a setup with all the bells and whistles, simply install a DC-DC charger. We recommend the Renogy 50A DC-DC Charger with MPPT. That single unit will quickly and properly charge our LiFePo4 batteries from either solar or alternator power, and it'll also isolate your LiFePo4 battery from your starter battery. Because it's an all-in-one box, it's an unbeatable value.

• Traditional battery isolation kits like our AUX-70x kits and the original VW auxiliary battery system, which charge the auxiliary battery at alternator voltage, will charge LiFePo4 batteries relatively slowly and won't always charge them fully. With the state of the market these days, it's a better value just to buy a DC-DC charger than to save a few bucks by using a LiFePo4 battery with a basic isolator.

• Shore chargers with a "LiFePo4 or Lithium" setting work great with these batteries.

• Solar chargers with a LiFePo4 setting will work to charge our LiFePo4 battery.

There are some simple rules to follow for making battery banks with these LiFePo4 batteries:

• These batteries must not be connected in series with each other to create a system at 24V or higher. If an individual battery became unbalanced, its BMS would cause problems.

• These batteries must not be connected in parallel with lead acid batteries unless they're separated while not charging (for example, while using one of our Auxiliary Battery Kits).

• Multiple LiFePo4 batteries can be connected in parallel to make a larger LiFePo4 battery bank a great option if you're out camping for long periods of time without charging.

Finally, here's some smart advice if you're using a smart charger: The onboard BMS in our LiFePo4 batteries is a brilliant failsafe to keep your battery in good shape for a long lifespan. If your battery isn't charging it,'s likely the over-discharge protection has been engaged. We've seen rare occasions when the BMS's protective features prevented other "smart" electronics, like our ProSport charger, from recognizing the battery and charging it. If your battery seems stuck in a protected state, try using another source to recharge your battery until the protection is unlatched - we've never had problems getting a battery charged back up on a "dumb" 12V charger, or our Auxiliary Battery kits. Once the BMS protection is unlatched, the smart charger will be able to charge the battery again. Take a look at the "Specs Sheet" tab to see the set and release points for various protections.

This product incurs an additional handling charge: $54 UPS Dangerous Goods fee

Note: The original, built-in battery chargers in all Eurovan Winnebago Campers are not capable of fully charging this type of battery. Additionally, all Eurovans have a factory "smart" alternator that doesn't steadily put out a high enough voltage to charge a LiFePo4 battery.

Two options to allow LiFePo4 installation in a Eurovan are:
• Use a solar panel and charge controller to charge your LiFePo4 battery, or
• Add a Renogy DC-DC battery charger/controller.

Auxiliary Battery - Lithium Iron Phosphate (LiFePo4 - 100Ah) Wrench Rating

• Handy — Requires some hand & power tools and minimal mechanical knowledge.

All Wrench Ratings

• Plug 'n' Play — Requires no or basic hand tools and no mechanical knowledge.
• Handy — Requires some hand & power tools and minimal mechanical knowledge.
• DIY — Requires a full tool set and broad mechanical knowledge.
• Pro — Requires professional-level tools, talent and experience.

Proposition 65: This product may contain chemicals known to the state of California to cause cancer, birth defects, or other reproductive harm.