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Choosing a 240V MPPT Solar Charge Controller HELP

DamonFlynn33

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Jul 16, 2021
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Hello Everyone - Newbie here,

I am currently in the design phase of an off grid system with 1 intention (for now) to charge an EV (shown below). I currently have 10 panels, 255W each (37V, 8.5A). I'd like to have them in a 5S2P configuration sending ~188V/17A to the MPPT charge controller/Inverter. I am looking to purchase two main things with your feedback = a battery and a MPPT C.C. I am leaning towards the 48V Lama from bigbattery - https://bigbattery.com/products/48v-lama that has a 115Ah 5.3Kw capacity. I am also interested in the LVX6048 https://www.mppsolar.com/v3/lvx6048 to handle a 240V 32A load. The charging demand is below (standard battery) and was wondering if ya'll could review this set up and let me know if it's adequate to charge an EV.

To be honest, I work from home and probably would be just fine charging at 120V, but would like the ability to charge it faster if in the event I have to go back into the office or use the vehicle more than it's intention.



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It looks like the LVX6048 inverter is rated at a 6kW continuous output, 6000w / 240v = 25a... That isn't enough for the 32a requirement of the Ford Level 1 charger demand. You'd have to parallel a couple of them to get the amps you require. Unless the car has a software setting to turn down the amps draw like the Teslas do.
 
Thank you Samsonite801. Based on what I've read on the internet (the internet NEVER lies), I can power another inverter with my battery (the LAMA) and be able to discharge 240V x 32A = 7680W load to the truck from my battery and solar.
As for the specification of the solar array & battery set up, do you feel the array is capable?
 
Ok, so hopefully I'm understanding what you're asking... So when I looked up the specs for that inverter, the LVX6048, it said the inverter output circuit can run at 6kW continuous, so that is all that inverter will ever put out, no matter what your drawing from (battery or solar watts)...

Your battery is rated at 5.3 kW/h (keyword: /h), that means it can give you 5300w for 1 hour time, then it becomes dead. Then you have 2550w worth of solar panels (at peak Sun BTW), so I'm afraid to say it, but it might take awhile to charge the truck (and if the truck doesn't have a software option to turn down the charger amps draw, then it will just blow breakers unless you get 2x LVX6048), then it will run until the battery goes dead and if the inverter is drawing more than the solar can supply the inverter will just shut down (or switch to utility grid power, bypass mode if it's grid tied).

Vehicles require enormous amounts of energy compared to an average house. For example, a Tesla Model S P100d has a 100 kW/h battery in it, so you would have to be able to pump 1000w in steady for 100 hours to fill it up (just some perspective).

Now if your truck stays nearly full most of the time, it may not take a lot to top it off. Keep in mind, on lithium it is better to not store the battery full to get maximum years life out of it.

Is that answering your question? If not, perhaps you can rephrase it a bit...
 
You don't have to charge at 32A, you can charge slower, often all the way down to 5A.

If you pick the right EVSE and SCC/all in one, you can have it throttle charging power according to battery level and solar input, so you only use the battery as a buffer for variations in solar output. That's assuming you will be able to charge it at home, during the day.

Most people also wildly overestimate how much charging they really need, so keep that in mind. What does the rest of your system look like?
 
You don't have to charge at 32A, you can charge slower, often all the way down to 5A.

If you pick the right EVSE and SCC/all in one, you can have it throttle charging power according to battery level and solar input, so you only use the battery as a buffer for variations in solar output. That's assuming you will be able to charge it at home, during the day.

Most people also wildly overestimate how much charging they really need, so keep that in mind. What does the rest of your system look like?
Hi Wilba, thank you for the reply. My set up is listed above. Lama 48V battery, 10 panel array, and an MPPT solar charger inverter, I'm still in planning stage. Was hoping to use a 240 inverter to charge faster. I do work from home and don't commute any longer, but want to know my total charging capacity on a 5hr sunny charging day...just in case of long trips or back to work commute..35 miles total. Even in slow mode charging at 4mph, I'd gain 20miles a day which I don't drive.
 
I recommend a lower power charging station as suggested. These are universal to be used by all EVs.

Consider a Clipper Creek LCS-20 that will charge fine at 16 amps 240v for 3.8 kW or about 10 to 12 miles per hour. Don't expect to run the charging at the max inverter specification. You need some headroom. Yes if you have a big drive it may take a few days to catch up. Save the faster charging capabilities for public stations on the road.

https://store.clippercreek.com/leve...20-lcs-20p-16-amp-level-2-ev-charging-station

I charge my I-Pace every day at work 4 hours at 16 or 20 amps and all works great.
 
Hi Wilba, thank you for the reply. My set up is listed above. Lama 48V battery, 10 panel array, and an MPPT solar charger inverter, I'm still in planning stage
Is that what you've got planned out for going off-grid in general, or what you're planning to use to off-grid charge a car?
 
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