Solar charged, portable, battery-powered charger

[Evbwcaer]

On the Electric Samba channel on YouTube he makes a Powerwall out of 18650's from "dead" laptop batteries.

One option in this scheme would be to make a small pack pack, maybe 3 kWh, from 18650's. If you combine a pack that size with solar, and then have the car charge at certain time intervals, you might be getting somewhere.

Assume you could fill the 3kwh battery twice per sunny day with three panels, and that a 3kwh pack could feed a 2000w inverter, which is feeding 1200w to the car, for 3 hours straight, with the solar buffering a little.

That gives about 6 hours of 1200w charging per day. Around 20 miles.

It would be a very cool project at least and might be practical in certain scenarios.

 

[evotorentals]

@Milmura,
Thanks for the info. We really appreciate it!

I did see on a twitter video someone use a suitcase to pull out a larger portable solar panel for charging but can't find such a product anywhere. Its at minute 6:31 at the first pinned video of Leilani Munter's Twitter page you can find here
Leilani Münter (@LeilaniMunter) | Twitter
(I also uploaded a screenshot)


We are researching something like this as we are a Tesla Rental in Canada.
It would be great for our customers, especially first time Tesla users / renters as it will lower their range anxiety specifically on longer road trips.

@hughconn
Let us know once you perfect such a build and we will happily purchase one from you.

Thanks,
The Evoto Rentals Team

 

[evotorentals]

@Evbwcaer
Thank you for your input

 

[Scubasteve04]

My set up:

2 - Renogy 12v 200ah In series(24v) -
1 - Victron SmartSolar MPPT 150/85 MC4
1 - Victron BMV-702 Battery Monitor
9 - 24v 320w Solar panels
1 - Samlex 24v 2000w 120v 16.7amp pure sine wave Inverter

1. With the mppt controller I have 3 mc4 inputs at 30a each. I have 3 panels in parallel for each mc4 connection using 10 awg cable. Also have a dc 32a switch for each of the 3 inputs as well. I use a 4 awg cable that goes from the mppt controller to the batteries, with a 100a fuse in between.

2. The 2 batteries connected are connected in series with a 0 awg cable. Then the positive and negative go into the Inverter with a 0 awg cable. In between the battery and Inverter is a 200a fuse and a Victron BMV-702 victron as my battery monitor.


I’ve slowly built this over the length of my model 3 pre-order. Learning a lot as I went. (Best Part).

But after reading this thread. Am I not going to be able to charge my model 3? I was just planning to charge it at 120v and 12-16 Amps.

Now I wish I knew someone who had a tesla, so I can test it.

The goal was to eventually upgrade the Inverter (48v) and add a couple more batteries (48v) and try charging at ac 240v at maybe 16a if I found a big enough pure sine wave Inverter and my batteries could handle it.

Let me know if you think I’ll be able to charge my car, or what I need to do to make it work. I’m going to be kind of upset if all this was just to power a portable AC unit for my office. Haha.

 

[miimura]

My set up:

2 - Renogy 12v 200ah In series(24v) -
1 - Victron SmartSolar MPPT 150/85 MC4
1 - Victron BMV-702 Battery Monitor
9 - 24v 320w Solar panels
1 - Samlex 24v 2000w 120v 16.7amp pure sine wave Inverter

1. With the mppt controller I have 3 mc4 inputs at 30a each. I have 3 panels in parallel for each mc4 connection using 10 awg cable. Also have a dc 32a switch for each of the 3 inputs as well. I use a 4 awg cable that goes from the mppt controller to the batteries, with a 100a fuse in between.

2. The 2 batteries connected are connected in series with a 0 awg cable. Then the positive and negative go into the Inverter with a 0 awg cable. In between the battery and Inverter is a 200a fuse and a Victron BMV-702 victron as my battery monitor.


I’ve slowly built this over the length of my model 3 pre-order. Learning a lot as I went. (Best Part).

But after reading this thread. Am I not going to be able to charge my model 3? I was just planning to charge it at 120v and 12-16 Amps.

Now I wish I knew someone who had a tesla, so I can test it.

The goal was to eventually upgrade the Inverter (48v) and add a couple more batteries (48v) and try charging at ac 240v at maybe 16a if I found a big enough pure sine wave Inverter and my batteries could handle it.

Let me know if you think I’ll be able to charge my car, or what I need to do to make it work. I’m going to be kind of upset if all this was just to power a portable AC unit for my office. Haha.

This is about what I consider the minimum useful configuration to charge an EV off-grid. The challenge will be finding an EVSE that allow more than 12 amps at 120VAC. Maybe you can just use the Tesla provided Mobile Connector and NEMA 6-20 adapter and feed it 120VAC. The other issue is matching the EV charging to the solar output so that you don't over stress your stationary batteries. Ideally, you want the EV charging to automatically slow down as the solar output drops and the stationary batteries approach 50% SOC. You also want to make sure that the inverter cuts off the AC output below a certain battery level to protect those batteries. The fastest way to kill lead acid batteries is to the cycle them to low SOC.

 

[ls7corvete]

My set up:

2 - Renogy 12v 200ah In series(24v) -
1 - Victron SmartSolar MPPT 150/85 MC4
1 - Victron BMV-702 Battery Monitor
9 - 24v 320w Solar panels
1 - Samlex 24v 2000w 120v 16.7amp pure sine wave Inverter

1. With the mppt controller I have 3 mc4 inputs at 30a each. I have 3 panels in parallel for each mc4 connection using 10 awg cable. Also have a dc 32a switch for each of the 3 inputs as well. I use a 4 awg cable that goes from the mppt controller to the batteries, with a 100a fuse in between.

2. The 2 batteries connected are connected in series with a 0 awg cable. Then the positive and negative go into the Inverter with a 0 awg cable. In between the battery and Inverter is a 200a fuse and a Victron BMV-702 victron as my battery monitor.


I’ve slowly built this over the length of my model 3 pre-order. Learning a lot as I went. (Best Part).

But after reading this thread. Am I not going to be able to charge my model 3? I was just planning to charge it at 120v and 12-16 Amps.

Now I wish I knew someone who had a tesla, so I can test it.

The goal was to eventually upgrade the Inverter (48v) and add a couple more batteries (48v) and try charging at ac 240v at maybe 16a if I found a big enough pure sine wave Inverter and my batteries could handle it.

Let me know if you think I’ll be able to charge my car, or what I need to do to make it work. I’m going to be kind of upset if all this was just to power a portable AC unit for my office. Haha.

Impressive setup, I would love to see pictures etc. I plan to do something similar, but as an alternative to generator for emergency (hurricanes).

Many people are driving their volts for months with out using gas. It sounds like your m3 will get enough solar to drive just as much.

 

[BerTX]

My set up:

2 - Renogy 12v 200ah In series(24v) -
1 - Victron SmartSolar MPPT 150/85 MC4
1 - Victron BMV-702 Battery Monitor
9 - 24v 320w Solar panels
1 - Samlex 24v 2000w 120v 16.7amp pure sine wave Inverter

1. With the mppt controller I have 3 mc4 inputs at 30a each. I have 3 panels in parallel for each mc4 connection using 10 awg cable. Also have a dc 32a switch for each of the 3 inputs as well. I use a 4 awg cable that goes from the mppt controller to the batteries, with a 100a fuse in between.

2. The 2 batteries connected are connected in series with a 0 awg cable. Then the positive and negative go into the Inverter with a 0 awg cable. In between the battery and Inverter is a 200a fuse and a Victron BMV-702 victron as my battery monitor.


I’ve slowly built this over the length of my model 3 pre-order. Learning a lot as I went. (Best Part).

But after reading this thread. Am I not going to be able to charge my model 3? I was just planning to charge it at 120v and 12-16 Amps.

Now I wish I knew someone who had a tesla, so I can test it.

The goal was to eventually upgrade the Inverter (48v) and add a couple more batteries (48v) and try charging at ac 240v at maybe 16a if I found a big enough pure sine wave Inverter and my batteries could handle it.

Let me know if you think I’ll be able to charge my car, or what I need to do to make it work. I’m going to be kind of upset if all this was just to power a portable AC unit for my office. Haha.

I don't get why you need a Tesla to test anything. It's just an electrical load of about 1500W. Plug in a space heater and crank it all the way up. You will get 5-6 miles of range on the M3 for every hour that you can run the space heater.

 

[Scubasteve04]

BerTX

It can handle a space heater at 1500w, so it was funny you said that. My concern was about the pure sine wave Inverter not being a true sine wave (I honestly think it is, but I’m not a pro) and if it will charge, even though there’s enough juice to charge something of equal power... Also if my battery set up was big enough because some people stated that it only turned on for a few minutes, then died. So if I needed to pick up a couple more batteries. it’s something I can do before my M3 gets here.

ls7corvete

My current off grid set up is used to power my office. It a safe but crude set up. I plan on moving everything to a better part of my garage and get it looking good for when my M3 arrives. I’ll take a bunch of pics and post it when I’m resetting it up, and when it’s done.

Miimura

Thank you for your input. That’s what my plan was. To have enough to charge just while the sun is up. I work from home a lot so it will be in the driveway charging a lot. I don’t want to dip into the battery at all really. My mppt controller has Bluetooth. So I figured I could keep an eye on the wattage the panels are bringing in. So when it hit 1200w. I’d start charging and set it to 120v 10a. And slowly as the solar brings in higher and higher wattage and hits 2000w. Use the tesla app and max it out to 16a. (Using the nema 6-20r the whole time) and slowly bringing it back down and stopping the charge when my battery has 70 or 80 percent left. So from 9:00am - 4:00pm (I live in California)

 

[tga]

Thank you for your input. That’s what my plan was. To have enough to charge just while the sun is up. I work from home a lot so it will be in the driveway charging a lot. I don’t want to dip into the battery at all really. My mppt controller has Bluetooth. So I figured I could keep an eye on the wattage the panels are bringing in. So when it hit 1200w. I’d start charging and set it to 120v 10a. And slowly as the solar brings in higher and higher wattage and hits 2000w. Use the tesla app and max it out to 16a. (Using the nema 6-20r the whole time) and slowly bringing it back down and stopping the charge when my battery has 70 or 80 percent left. So from 9:00am - 4:00pm (I live in California)

Some people are trying to reverse engineer the HPWC protocol to change the charge current on the fly and track solar output.

See: New Wall Connector load sharing protocol

 

[miimura]

Some people are trying to reverse engineer the HPWC protocol to change the charge current on the fly and track solar output.

See: New Wall Connector load sharing protocol

I was going to mention that too, but you have to use a Wall Connector and it must have 240V. So, if he upgraded his inverter and batteries, that would be just about the best and most automatic setup.