Blog Post

Choosing the Right Battery for Backup Power or Off-Grid Applications in Canada


Share This Post

If you live in Western Canada, there are several different reasons why you might want to add on-site storage to an existing home or business:

  • Grid-Tied Backup Power
    You can combine battery storage with grid electricity to ensure a steady supply of reliable, uninterrupted power. This approach is often used by data centers, military installations, and medical units. And it’s becoming increasingly popular among homeowners who live in areas with frequent brownouts and outages. For grid-tied backup storage, you’ll need a standalone inverter (to power backup loads) and a critical loads panel.
  • Off-Grid Backup Power (with Solar)
    You can combine batteries with solar panels in situations where grid connectivity isn’t possible – e.g. remote cabins and vacation homes. This approach requires photovoltaic (PV) panels, a critical loads panel, and a battery-ready solar inverter.
  • Grid-Tied Backup Power (with Solar)
    Adding batteries to a grid-tied solar installation is quickly becoming the most popular application for on-site storage technology. This combination not only provides backup power and reliable nighttime electricity (once your PV panels stop working), but it also helps to reduce your reliance on the grid – allowing you to lessen your carbon footprint.

Which battery type to choose ultimately depends on your energy goals. This article explains some of the pros and cons of competing storage technologies – plus what (if any) modifications are required when adding batteries for solar power to your own home or business.


Best Batteries For Your Solar Power

Lead Acid Batteries 

Lead acid batteries are the most popular type of storage technology on the market. And they come in 2 main varieties:

  • Flooded Lead Acid (FLA)
  • Absorbent Glass Mat (AGM)

FLA Batteries
Flooded lead acid batteries rely on free-flowing liquid electrolytes to transfer and store electricity within the encasement. They rank among the least expensive of all battery types, making them an obvious favourite among homeowners and commercial properties with solar power. They’re also capable of operating in cold weather when housed in an appropriately insulated battery box. 

But flooded lead acid batteries aren’t without their downsides:

  • They tend to be heavy and cumbersome, making them difficult to work with.
  • Flooded lead acid batteries have a relatively low cycle life of 1,000.
  • They require frequent maintenance, which can drive up the long-term cost.
  • Flooded batteries require ventilation since they release toxic gases. They also must be stored upright to prevent the liquid contents from spilling out.
  • They have a recommended depth of discharge (DoD) of only 50%. While it’s possible to discharge deeper than this, doing so drastically reduces battery life. 

That being said, their cold-weather performance and low price point make them worthy candidates for off-grid applications. And with optimal system design, it’s possible to maximize battery life. You can further mitigate some of the downsides by choosing top brands like:

  • Discover Battery, whose SOPzS tubular storage technology offers a cycle life of 2,000.
  • Rolls, whose premium deep cycle storage solutions deliver a cycle life of 3,000.

AGM Batteries
Absorbent glass mat (AGM) is another type of lead acid battery that also uses electrolytes to conduct and store current. The primary difference is that these electrolytes are suspended in fibreglass mats instead of as a free liquid. As such, they qualify as a “dry” storage technology. And because the entire casing is sealed, this battery solution can be stored in any orientation.

AGM batteries deliver comparable performance to their flooded counterparts (including a modest DoD of 50%). However, they have zero maintenance requirements. And this makes AGM batteries ideal for those who want to “set-it-and-forget-it” – whether for backup or off-grid applications. They also pose fewer health and safety risks since AGM batteries don’t release toxic gases. Better still, they’re compatible with nearly every type of solar inverter – making installation quite easy.

The downside is that AGM batteries cost more than FLA storage solutions do. They also have shorter lifespans, averaging 3-5 years instead of the 5-7 years that come standard with flooded acid batteries.  

Despite these disadvantages, AGM batteries still enjoy widespread appeal:

However, if the goal is to combine storage with solar to reduce grid reliance, costs, reclaim nighttime electricity, or ensure more reliable backup power, you may be better off exploring the battery technologies below.  


Lithium Batteries 

If you own a phone, laptop, or any other smart device, you’re probably already familiar with lithium batteries. They’re the storage technology of choice among electronics manufacturers around the globe. And they increasingly feature in more solar applications, either in the form of lithium iron phosphate (LiFePO) or lithium-ion (Li-ion) batteries.

LiFePO Batteries
LiFePO is a dry battery technology that uses lithium iron phosphate in the cathode – and graphite in the anode. And there are several reasons why this storage solution has garnered so much attention in recent years:

  • LiFePO batteries have a depth of discharge of 100% – making them some of the most efficient on the market. They’re also more reliable than lead acid batteries due to their constant discharge voltage.
  • They have a cycle life of 10,000, allowing them to ship with warranties of 10 years or more.
  • LiFePO batteries are incredibly light, making them much easier to work with.
  • They’re stable – posing little risk of overcharging. They’re also non-toxic.

However, LiFePO batteries do have certain drawbacks:

  • Because LiFePO is a relatively new technology, it’s still quite expensive. This novelty also makes these batteries harder to source, troubleshoot, and repair. 
  • LiFePO batteries experience performance issues when the temperature dips below 20°C. So if you choose this technology, make sure you have enough room to install it indoors. This is especially important if you live in a colder region (like here in Western Canada).

SimpliPhi is a leading pioneer in the LiFePO battery field. And we frequently use their storage solutions to help clients conserve space or eliminate maintenance requirements when replacing existing FLA banks.

Li-Ion Batteries
Li-ion is also a dry battery technology – except the cathode is made from either lithium manganese oxide (LMO) or lithium cobalt dioxide (LiCoO2). Performance-wise, it shares many of the same benefits as LiFePO, including:

  • Long lifespans (10+ years on average)
  • A high depth of discharge (up to 100%)

Because of these advantages, Li-ion batteries are quickly becoming the industry standard – not just for solar but also for electric vehicles (EV’s). And this growing popularity means you’ll have more buying and support options if you also choose Li-ion.

But as always, there are drawbacks.

Although somewhat cheaper than LiFePO alternatives, Li-ion batteries are still considerably more expensive than lead acid storage solutions. This price difference is usually worth it for everyday use – like for residential nighttime power. But the higher price becomes harder to justify for solar PV systems with infrequent usage. To power a vacation home that you only visit a few times a year, for example, FLA or AGM batteries may be the better choice.


What Do We Use (and Why) As A Solar Company

As a solar company, at EVOLVsolar, we install the full spectrum of storage technologies – based on the client’s energy goals. For off-grid applications or properties with infrequent use, we tend to favour FLA or AGM batteries due to their affordability and cold-weather performance. But for long-term benefits with zero maintenance, we strongly prefer lithium batteries – especially if solar is involved.

More specifically, we enjoy working with lithium-ion batteries from LG Chem and Tesla.

Why LG Chem?
Because of their high DoD, the LG Chem RESU10H line of batteries deliver outstanding performance. As long as you install these in a heated space, you can expect up to 8.8kWh of on-demand energy. And although they don’t ship “solar-ready,” LG Chem batteries are easy to configure with SolarEdge or Huawei inverters. This ease and flexibility impressed us enough to frequently offer this product as an LG Home Battery Certified Installer. As a bonus, they’ve recently become CSA-approved in Canada.

Why Tesla?
Tesla is the undisputed leader in Li-ion storage technology. In fact, it has a $5 billion gigafactory dedicated to nothing but batteries (for its growing electric vehicle fleet). And it also has a solar-specific battery – the Tesla Powerwall 2 – which is fast becoming our preferred storage technology for PV installations.

Some of the key benefits of the Tesla Powerwall 2 include:

  • Unlimited cycle life – backed by 10 years of warranty coverage. 
  • A DoD of 100%, with up to 13.5kWh of usable energy (7kW for peak power). 

In addition, these batteries ship “solar-ready” with an internal inverter. And this makes them one of the easiest storage technologies to work with. Better still, they’re preconfigured for EV-charging. And not that it matters, but Tesla’s batteries have the most aesthetically pleasing design.

Given these benefits, it should be no surprise that this is a regularly sought-after product. For design questions, speak to one of our Tesla Powerwall Certified Installers today.

Which Battery Type Is Right for Your Solar Panels?

Still not sure which on-site storage technology makes the most sense for your home or business?

Let us help.

Whether you want batteries for a new PV installation, an existing one, or grid-tied storage (without solar), we can guide you through the different options to make sure you achieve your energy goals.

To get started, schedule a free consultation with our energy experts today.

EVOLVsolar is Western Canada’s leading solar company. We have one mission: to make solar energy affordable while giving back to the environment. By investing in solar power, you can save money on energy bills, upgrade the value of your property and reduce your energy output. You can expect high-quality solar panel installation, world-class workmanship, excellent customer service and the best solar technology available. Our success has established us as the go-to solar installers in BC and Saskatchewan, and one of the leading solar companies in Alberta. Experience the EVOLVsolar difference by contacting our corporate office today at (587) 602-0534.

Subscribe To Our Newsletter

Get updates and learn from the best

More To Explore

Ready to Go solar?

Our solar experts are here to help you get started. Just leave your contact details to request a call back.