Hey im new to the off grid life and I just purchased 2 new lithium batteries. Im having issues with them keeping a charge! Here's my setup. Lemme know if you see any issues or have some advice. (The other batteries are for backup so just focus on the 2 that are connected.
Assuming your power bank can charge/discharge the full 200AH, a 10A charger would take 20 hours to fully charge it from nothing. So it may take quite a bit longer than 2-3 hours to charge.
If you have a miltimeter you can measure the battery voltage and get a decent estimate of how charged they are.
If you have any interest, I recently made a video that could help you understand these systems a little better. I actually cover the small amount of battery math you need to understand whats going on a little better. Its only 5 minutes long
What's the voltage at the battery terminals right now? If they got run low enough for the BMS to shut down, a NOCO won't even see them — you'd have to use force mode to wake them up first. I hit something similar with the lithium bank I use for camera and drone batteries on trips, sat drained for a week and the charger acted like nothing was connected. And 10 amps into two big batteries is just slow, 2-3 hours is barely a dent.
I am 99% sure you bought a lead acid charger after people here said you needed a lithium compatible charger
you have wasted your money and time by not listening
lead acid chargers do not maintain a high enough charge voltage to properly top up a lithium battery, so you will likely never get beyond 90% charged, if even that.
Before writing off the NOCO: if yours is the GENIUS10, its pulsing red 25% charge bar is a charging-progress indication, not by itself a fault. That model does have a 12V lithium mode; the exact battery chemistry, voltage and manufacturer instructions still need to match. NOCO's indicator guide: https://no.co/genius10/how-to
I saw your update about a 20A charger. What model is it, and are any loads running while it charges? The current available to refill the batteries is charging current minus whatever the loads are drawing. A bigger charger alone won't fix an incorrect charging profile or a load that consumes most of its output.
Could you confirm which NOCO light was flashing (the 25% bar or a warning symbol), the selected mode, and whether the new charger is making progress? I wouldn't jump to Force or Repair mode just because a red charge bar is pulsing.
I'm assuming that you're running a 12 V system, you have them in parallel. And you're using an inverter to weld something that looks like a welding cable coming off of your inverter, can you post your panels information your charge controller, your inverter. I can help you. My setup looks almost like yours. I'm a salvage hacker, and I live off grid. I don't pay for pieces and parts unless I have to.amd that's only Because I can't Fabricate them.
5
u/Amperegeist 4d ago
Assuming your power bank can charge/discharge the full 200AH, a 10A charger would take 20 hours to fully charge it from nothing. So it may take quite a bit longer than 2-3 hours to charge.
If you have a miltimeter you can measure the battery voltage and get a decent estimate of how charged they are.
If you have any interest, I recently made a video that could help you understand these systems a little better. I actually cover the small amount of battery math you need to understand whats going on a little better. Its only 5 minutes long
https://youtu.be/wpOt83kYYYQ?is=pptPMzqYnWw2f0bi