
Drop-In Lead Acid Battery Replacement | Safe Reliable Off-Grid Power

Lead Acid Battery Replacement: An Off-Grid Winter Power Guide
A guide for choosing safe, reliable energy storage to replace lead acid batteries to provide off-grid power for your home.
For homeowners who live off-grid, preparing for winter is serious business. With solar production at its lowest when temperatures drop, an energy storage system must be able to produce enough power to carry a home through long winter nights and periods of inclement weather.
Many first-generation off-grid systems include lead acid batteries to provide energy storage. What many homeowners don’t anticipate, however, is how frequently they will end up relying on their backup diesel generator as their lead acid batteries age, lose capacity and no longer produce enough energy to power through winter’s extended periods of darkness. This adds additional cost for fuel and maintenance of your generator, fumes, pollution and noise while potentially shortening it’s lifespan as well.
If this sounds familiar, it may be time to consider replacing your lead acid batteries with Lithium Ferro Phosphate (LFP) batteries — a safe, non-toxic and highly efficient lithium ion alternative.
A common misconception is that lead acid batteries are less expensive than LFP batteries. The reality is that you have to buy double, triple or even quadruple as many lead acid batteries as you do lithium-based batteries to achieve the same usable capacity, and replace lead acid battery banks more frequently during the lifetime of your off-grid system, as often as 2 to 3 times depending on the type of lead acid (AGM, VRLA, Flooded, Gel). Take a look at our Lead Acid Replacement Calculator to run the numbers for yourself.
Beyond upfront pricing, LFP batteries will save you money over the long term as they do not require annual maintenance.

Installation
SimpliPhi is the only lithium ion battery maker to offer a “drop in” lead acid replacement. This means that you will not have to change your existing inverters or other equipment when you swap out your batteries. The only change is the programmed settings in the inverter charge controller. Additionally, our batteries utilize similar terminal connections, which means your battery cables will also be compatible. SimpliPhi Power provides integration guides for the most popular off-grid inverters and charge controls. Changing out your lead acid batteries will require reprogramming your system, and our team is here to help you through this process to make the transition seamless.
That said, PHI batteries are significantly smaller, lighter and more efficient than lead acid batteries, meaning that your energy storage system will take up less room, weigh considerably less and provide more usable capacity in a smaller battery bank. One tiny home owner recently was able to replace eight lead acid batteries with three PHI 3.5 kWh LFP, eliminating more than 800 pounds of weight and recovering more than half the space required for her battery bank.
Transportation
Many off-grid homes are in remote locations. Here too, the compact size, lightweight and available energy density of PHI batteries makes a real difference. When every square foot and pound of container space, small plane or boat comes at a premium, PHI batteries translate into big savings.
Safety
Unlike lead acid batteries, SimpliPhi’s energy storage solutions do not require ventilation or cooling and will not overheat. They are also safer than other lithium ion batteries because LFP does not contain cobalt, which is the source of toxicity, hazards and ‘thermal runaway’ associated with other lithium batteries. LFP is environmentally benign, non-toxic and safe for your home and family.
Off-Grid Residential SimpliPhi Solutions
Model | Type | Features |
---|---|---|
PHI Batteries | Hard wired* |
|
AccESS Energy Storage System | Turn-key hard wired* |
|
*Initial installation by a licensed C10 or C46 electrician required
SimpiPhi’s applications engineers and I.Q. Certified Installers can help you calculate how much energy storage capacity you will need and what solution is best for you. Our storage solutions have been proven in the field for a decade, including by the U.S. military in Iraq and Afghanistan.
RESOURCE LIBRARY
Deployment Story: Easy, Drop-in Lead Acid Replacement in Canada
Blog: Temperature Effects on PHI Batteries vs. Lead Acid
Blog: Know Your Battery Specs: Nameplate Capacity (10 kWh) vs. Usable Capacity (7 kWh)
Video: Be Green Solar Demonstrates Lead Acid Battery Replacement with SimpliPhi Power Batteries
Sizing Tool: Link to Lead Acid Replacement Calculator