I have a couple of the Growatt 3000lvm inverters in series with four 48v 100a batteries. Because I'm using DIY batteries they don't communicate with the inverters and it ends up using some battery power during the day. I've gone around and around with this issue and, long story short, I have a few extra panels and a charge controller. Is it possible for me to add the charge controller with a few panels to the battery pack and use it strictly for charging?
Can I Add a Charge Controller?
- Thread starter Solargrow
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73powerstroke
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Does the cc support 48v. If not, you need on that does.
BradCagle
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I have a growatt sc4880 charge controller, which configures the same a the hybrid inverter. I use DIY batteries too. But I don't have a problem with it using up battery during the day. Well I take that back I did, until i fixed the config.
what battery type (menu 05) do you have yours on? use, or us2?
I haven't had a laptop to flash them until recently so I still have to try that option. I've been trying to work with Signature Solar on some solutions but I just can't deal with their lack of customer service.
BradCagle
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Alright, that was the one I had troubles with. I know that's the one you're "supposed" to use with lithium that has no BMS communication, but I could not get it to work correctly as it stops charging early causing loads to use my battery when the sun is still up.
I switched to "use", and all is good now.
On a side note, I might try "us2" again because digging around seems like it may work correctly if you set the float voltage (menu 20) to the same voltage as C.V. charging voltage (menu 19)
I have two Growatt 3000w set up in Split Phase mode. Each has its own array. I also have an EPEver AN with its own array. They all charge the same battery bank. Under light load, when the battery is at a high SOC, only one charger will be doing any work. But if a cloud passes or the load increases, each charger will behave according to its settings. Each array has a breaker, which is nice of I want to confirm one array is working properly. I can just open 2 of the 3 breakers and let that one charger do all of the work and see how it is preforming.
Excellent! Thanks for that.
Another note, which might be the source of your original "problem", in my testing the AC charging wouldn't kick in until the battery had went from 100% to 75% in the Grewatt internal logic. The data history log shows the battery 100% when in fact it was lower and when it started charging it was at 75%. These percents are based on voltages and part of the internal charger logic. That might explain while there is always some battery discharge. The power to run the inverter (even its display) comes from the battery. I had mine wired on a transfer switch to a sub-panel. I had the AC on, solar on, but the inverter off. The battery had some amount of daily charge and discharge because of the internal power used. I ended up killing the AC input and the solar input so it would shut down and just sit there until needed.
BradCagle
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Just use "USE" battery mode. It works how you would expect.
"US2" sucks, I tried it again with the charge voltage, and the float the same this time. What it does is it charges to the charge voltage, then stops. Then your loads will pull from the battery, then the MPPT will kick in again, this cycle sucking power from your battery, and then pushing back int just keeps continuing.
"USE" mode charges the battery, then senses the actual load power, and will lock to that load current, powering the load without draining the battery. Done
"US2" sucks, I tried it again with the charge voltage, and the float the same this time. What it does is it charges to the charge voltage, then stops. Then your loads will pull from the battery, then the MPPT will kick in again, this cycle sucking power from your battery, and then pushing back int just keeps continuing.
"USE" mode charges the battery, then senses the actual load power, and will lock to that load current, powering the load without draining the battery. Done
Brad, thanks for the review of that setting. I knew I had tried it but forgot why l moved to USE.
So what kind of settings do you use them? Specifically 12, 13, 19, 20, and 21? I have the 48v model.
Do you have separate charger rates for 19 and 20? Right now I have them both at 56.5. The other day I changed 13 (when inverter will switch back to battery?) from 53 to 55 and t seemed to help but now the batteries are dead by 8pm. That's 19kw powering a couple mini splits from 300 to 2000 watts. Even if it was maxed out at 2000 watts 24/7 my batteries should be lasting at least 8 hours...
Do you have separate charger rates for 19 and 20? Right now I have them both at 56.5. The other day I changed 13 (when inverter will switch back to battery?) from 53 to 55 and t seemed to help but now the batteries are dead by 8pm. That's 19kw powering a couple mini splits from 300 to 2000 watts. Even if it was maxed out at 2000 watts 24/7 my batteries should be lasting at least 8 hours...
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