Q+A: In a Complete Off Grid Solar System with Batteries, How Many Batteries Do I Need to Go Off the Grid?

Q+A: In a Complete Off Grid Solar System with Batteries, How Many Batteries Do I Need to Go Off the Grid?

Q+A: Is going off the grid legal? Reading Q+A: In a Complete Off Grid Solar System with Batteries, How Many Batteries Do I Need to Go Off the Grid? 5 minutes Next Q+A: What do the maintenance costs look like after the initial off grid solar setup?

How many batteries do I need to go off-grid in New Zealand?

Start by asking what you plan to run, not how many batteries you need to go off the grid. The standard three bedroom household will likely require 8-12 12V batteries. The more you intend to live like a person on-the-grid, the more batteries needed.

This isn't a question with an easy answer - there's no number that fits everyone, and all batteries are different. Technically, you can go off-grid with one 12V 200aH battery but that's only if you're not planning to power a minimal amount of things like a minifridge and lights as an example. We've taken the guesswork out for you in each complete off grid solar system with batteries kit. After you’ve asked yourself what you’re planning to run on the batteries, something else to consider is how you structure your power use. If you intend to use the bulk of your power during the day, you will need less batteries. Make sure to purchase your batteries from a reputable supplier, like GridFree - or if you're looking beyond just batteries, consider one of our off grid solar system packages with batteries included. We've taken the guesswork out for you with our kits - each is a complete off grid solar system with batteries, designed for different levels of power usage. 

 

What is the best battery for off-grid solar?

Wondering what's the best battery for going off grid? Not all batteries for off-grid are the same - we have three kinds of batteries available as stand-alone purchases or as part of our off grid solar system packages with batteries. Our standard 200Ah Gel Deep Cycle Battery is a workhorse that is popular with our customers, offering a balance of being a great battery at an affordable price, with the shortest lifespan of 3-7 years if treated well.

This battery is 60kg and has a 50% usable depth of discharge. It's safe and compatible with almost all charge controllers and inverters. Then, there's our Lead Carbon Battery that has a slightly longer lifespan of 7-10 years and is in the middle of the pack price-wise too. Finally, we have Lithium Ion Batteries, the Growatt ARK LiFePO4 Battery 2.56kWh, with a 10-15 year lifespan, clocking in at 30kg each, and an 80% usable depth of discharge. Learn more about the differences between these three battery types. Make sure to purchase your batteries from a reputable supplier, like GridFree, or if you're looking beyond just batteries, consider one of our off grid solar system packages with batteries. 

What voltage is best for off-grid?

A lot of off-gridders think 12V is best because you use less power. Our standard 200Ah Gel Deep Cycle Batteries come in 12V and when you have more than one they can be configured as a 24V or 48V battery bank. (Note that our Lithium batteries only come in 48V.) We would say 48v is the best—the higher the voltage of a battery, the bank is more efficient. That being said, consider the voltage of most of your appliances. If you've already got a bunch of appliances that will run off a certain voltage, then that's might be what's right for you. However you can also install a step down to convert a 24/48V bank to 12V, or an inverter to convert any of the to 240V AC (what most household appliances run on).

Anything up to 120V DC, you can DIY; voltages above that need to be legally installed by an electrician. Each complete off grid solar system with batteries we offer is designed to be DIY, though you would need an electrician to wire anything into a household switchboard.


How do I practice good maintenance for my batteries?

Mostly our batteries are set and forget, being essentially maintenance-free, but there are a few good rules of thumb to get the most out of your batteries for the longest lifespan:

  1. Put your off grid battery for solar in a good spot where it won't get excessively hot or cold.
  2. Keep the battery out of the weather and away from moisture.
  3. Everyday, make sure you're not discharging the battery too deeply as that reduces capacity over time and can lead to a shorter lifespan.
  4. Make sure you recharge your battery to full as soon as you can after using power - don't leave it partially charged for more than a day if possible.
  5. Find more tips for good battery maintenance here.