I'm looking for some guidance on how to properly expand my battery capacity. Currently, I have a setup with 5kWh of 48V LiFePO4 batteries. Is it possible to add a 48V lead-acid battery bank to this setup, or should I stick with the same type? Also, if I choose to add another 2kWh of 48V LiFePO4, how do I prevent balance issues between the different batteries? What steps should I take on the inverter or charge controller side when making these changes?
3 Answers
If you're adding batteries of the same chemistry, like LiFePO4, you can do that. Just keep in mind that batteries of different sizes might not balance perfectly—it's common to check and reset their state of charge (SOC) regularly.
You really shouldn't mix lead acid with LiFePO4 batteries in parallel. Their voltage behavior is so different that it can lead to problems. If you're adding more batteries, it's best to stick with the same chemistry to avoid issues.
What if you already have a combo set? Should you just use a separate inverter to avoid the issues?
Nah, you can't mix different types in parallel. For lithium batteries, you'd want them to match perfectly. If you're considering using 12V batteries in series to make a 48V setup, that could work as long as they’re all the same type and capacity.
Got it! So, for any upgrades, it seems like keeping them uniform is key.
Right! And even if they drift a bit, they'll generally share the load over time if set up correctly.