What to Consider When Upgrading Your Power System

Thinking about expanding your off-grid power setup? Whether you’re adding more battery capacity, upgrading your inverter, or throwing a few extra solar panels in the mix - there are a few things you really need to think about before diving in.

KEY TAKEAWAYS

  • Match your batteries:Use new batteries that match your existing ones in brand, chemistry, size, and age to avoid performance issues.
  • Ensure new solar panels are compatible with existing ones:Solar panels need to be of similar voltages (within 1V) in order to avoid diminished solar harvest.
  • Ensure the correct Solar controller size: Make sure your solar controller can handle the extra load of additional panels, or use a separate MPPT for new panels.
  • Upgrade cabling when necessary: Ensure your cable sizing can handle the new loads created by upgrading solar, inverter or battery sizes.
  • Upgrade battery chargers: If your battery charger is too small for your larger battery system it will take longer to replenish used capacity.

ADDING MORE BATTERY CAPACITY

More amp hours = more freedom, right? Sure—but don’t just chuck a new battery in next to your old ones and hope for the best.

Here’s what can go wrong:

  • Old + new batteries don’t mix. Batteries naturally lose capacity over time. If you pair a fresh battery with one that’s already a few years old, the new one will only perform as well as the old one. Best case? You shorten the life of your brand-new battery.  Worse case?  Charging issues, premature failure of one or more batteries and output performance problems.
  • Don’t mix chemistries. Lithium and AGM batteries have completely different charging profiles, voltage ranges and behaviours. Pairing them together is a fast track to damaging one—or both.
  • Don’t mix sizes. Bigger batteries take longer to charge, and if you’ve got a small one connected to a larger one, it will be “force fed” while the system tries to top up the big one. That’s not great for battery health, longevity or ultimately system performance.

Bottom line? If you’re expanding your battery bank, your new batteries should be the same brand, chemistry, size, and age as the existing ones (we recommend within 6-12 months for our AllSpark batteries) —or better yet, throw your old batteries on Market Place and start fresh with the right capacity for your needs.


ADDING MORE SOLAR

More solar panels can be a great move—especially if you’re planning to stay in one place for longer than usual, or using more of those higher powered devices (hairdryer anyone?). But before you start making changes, here’s what you need to know:

  • Fixed panels (Glass or lightweight): If you're adding new panels to a roof setup, they’ll need their own controller—unless they have very similar specs and your current solar controller is big enough to handle the extra wattage.  Not sure if your setup qualifies? Drop us a line—we're happy to help you figure it out.  Any panels you put together with others must be the same – Parallel connection – match the voltage, Series connection – match the amperage.  This is important to avoid cell damage to panels.  Ideally just match all panels the same for any string and add an extra MPPT Solar Controller for different panels.
  • Portable panels: These should never be connected to the same controller as your fixed solar setup. Even if the specs match and your controller is technically big enough, it doesn’t work efficiently. Why? Because the controller treats all connected panels as one big array—so if one panel ends up in the shade, your whole solar harvest is dragged down to match it.  Almost always, angle to the sun, the voltage of the panel and sun vs shade will be different.  Use a separate MPPT for roof and portable.

Moral of the story? Each solar input needs its own controller unless you’re absolutely sure they’re a perfect match, and they are in the same physical area (experiencing the same conditions).


 

UPGRADING YOUR INVERTER

Wanting to run higher powered appliances? Moving from a 1000W inverter to something larger like a 2000W or 2500W? Nice. Just make sure your wiring can handle the extra current draw—in some instances, you may need to rewire the whole system with thicker cable to keep things safe and efficient. A cable that is too small can result in voltage drop and (in extreme cases) fires due to excess current, meaning your appliance will not run as intended (if at all).

And don’t forget to check your batteries. Not all batteries can handle the current draw of a big inverter - with a minimum 175A continuous output and most at 200A+, every AllSpark lithium battery can handle at least a 2000W inverter with some as high as 3500W from a single battery

 

CHECK YOUR CHARGERS AND CIRCUIT PROTECTION

With more solar or batteries in the mix, you’ll need to check that your DCDC and ACDC chargers are up to the task. An undersized charger will bottleneck your system and slow everything down.

And finally - don’t forget about circuit protection (circuit breakers or fuses). Any changes to cable size, current draw, or charging rates will likely require new fuses or breakers to match. Incorrect circuit protection and undersized cables is one of the major causes for those fires you see in the news.

 

NEED HELP?

If you're not 100% sure what’s compatible or what needs changing, we’re here to help. Send us some photos of your setup and what you’re trying to achieve, and we’ll walk you through it.

Upgrading your system should feel empowering—not overwhelming. Get it right the first time, and your future self (and your fridge full of cold beers) will thank you.

 

FAQS

  • Can I add a new lithium battery to my old ones?Only if they are the same brand, size, chemistry, and within 6–12 months of age. Otherwise, start fresh with a new matched set.
  • Can I mix lithium and AGM batteries in the same setup?No. They have different charging profiles and will damage each other if combined.
  • Do all solar panels need their own controller? Not always. Panels with identical specs (or within 1V) can share a controller if it’s sized correctly. Otherwise, use separate MPPT controllers.
  • Can portable solar panels be connected to the same controller as fixed roof panels? No. Portable panels should always have their own MPPT to prevent shading and efficiency losses.
  • What do I need to upgrade when installing a bigger inverter?Ensure your wiring and circuit protection can handle the higher current draw, and check your batteries are rated for the load.
  • Why is circuit protection so important?Incorrect fuses or undersized breakers are a major cause of fires in 12V systems. Always match them to your cables and loads.