So I asked the question on a DIY Solar forum, about the buffer for a battery connected to an inverter. Here is the link to my question, where an admin is answering my question. My monthly usage for my home is low, so I can get away with a 4K system for a back up off grid. Iāll let you know what they say. I can build my system for about $6500 without electrician fees to hook everything up properly. Buying used solar panels, $1500 inverter and about 1500 for a ground mount ballast using cement blocks and a $1500 5k old server battery.
That one growatt will only give you 15amp capability from the charger (safely). They are stackable though, so might want to consider 3 to get to at least 40a capability. I've gone through a lot of back and forth on the inverter and decided on split phase capable 6548s (because I still need 120 and didn't want to add transformer). Still, that configuration will neuter (derate) the pro charger to ~40a, but in the future might and another pair of 6548s.
, although real estate for panels is not free. So if I need to increase solar I will need to buy more efficient panels. I used the panel savings to buy 20kWh of batteries.
that I get my truck tomorrow.So a single LV6548 will run 240v@40 amps???? I thought you had to stack them for 240v output.That one growatt will only give you 15amp capability from the charger (safely). They are stackable though, so might want to consider 3 to get to at least 40a capability. I've gone through a lot of back and forth on the inverter and decided on split phase capable 6548s (because I still need 120 and didn't want to add transformer). Still, that configuration will neuter (derate) the pro charger to ~40a, but in the future might and another pair of 6548s.
" Panels are cheap, batteries are expensive." Your not kidding, I found panels for free, haven't found a free battery yet
Hoping to use the three day weekend to set this up and do some current measurements with the travel charger while I wait for the Pro charger. That's with
You are correct, 2 are required. I am using 2 to start and see how well it performs charging, before considering a second set. I.e is 40a enough to support my daily mileage needs.
You should without a doubt do an off roof installation if you have the space. You will generate a lot more energy that with a roof mounted system. I have 24 solar panels that are ground mounted and am getting about 60-65KW generated a day even with these 100+ degree Texas days on non cloudy days. During the spring hours I can get more than 70KW in a day. My neighbor has a roof mounted system and gets much less than that. My solar people tried to talk me into doing a roof, but I already did my homework to know that ground mounts will get sun on the all day long unlike roof mounted panels.
I looked at that unit, but it is not expandable and I suck at predicting the future (or my original system would have included charging a Lightning). My charging calculation on that unit dropped to 32a. The wiring cost of adding additional inverters is pretty painless at this point.
what do you mean by charging calculation? The Growatt looks like it could push 40 amps with room to spare. I havenāt built a system like you have and I would be interested in seeing your calculations. Also, are you looking at a standard range truck with 9.6?
At perfect efficiency the Growatt would deliver 50A total. 80% of that would be 40A (what you should draw across a breaker). The problem is I haven't seen an inverter with 100% efficiency (Growatt is listed as 88% peak efficiency), so 88% would put it at 44A and 80% of that is 35A. Again that's stating that the only thing you are running is the charger at the time. I'm sure you can push these limits and may never experience a failure. Also these limits are based on continuous operation numbers provided by the manufacturer, not the peak numbers (which are usually rated as sustainable for a couple seconds i.e Growatt is 36kW surge, 12kW continuous).
My ground mount wasnāt much more because itās of the proximity to my meter. With my batteries online for the past two months my bill is around -$650. I wanted a solar and battery system that would power my entire home and two EVās. So far itās been doing that and I havenāt lost any power like my neighbors have in the past 3 months. Worth it to me.
