EV battery output connected to inverter solar input

[Hyena]

Hey guys,
Does anyone know how the MPPT circuitry in an inverter would handle fixed DC voltage instead of the input from solar panels?
I'm wondering if I can connect a 350-400v EV battery to the solar input of an inverter.
The DC voltages are in the same range so technically the 5000w inverter would only pull around 13A from the EV pack to max out it's AC output.

Would this work or is it a recipe for magic smoke ?

 

[Hedges]

It's been done here a couple of times, reported on the forum. Maybe it was 200V pack, but same idea.
I would worry about inrush, would like to connect through a light bulb before hard connecting.

 

[Hyena]

It's been done here a couple of times, reported on the forum. Maybe it was 200V pack, but same idea.
I would worry about inrush, would like to connect through a light bulb before hard connecting.

Cool, I did a search but couldn't find anything. So much discussion using the same keywords so may have been lost. If anyone who's done it can chime in on how it's going that'd be great.
The inrush is a good point. 2x 240v bulbs in series would probably do the trick!

 

[Hedges]

I'm not finding them either.

One guy had an older big-name GT PV inverter and was trying to trick it into operating off-grid with EV battery connected to PV input..
We talked him into getting something like MPP hybrid or similar. It worked batteryless, but wimpy, only started small motors. So I told him to string four car batteries together for 48V. It was able to draw starting surge from that and power larger tools.

Lots of inrush experience around here with lithium batteries and inverters, blows fuses and welds contactors. Don't know if it has blown capacitors or not. Haven't heard of issues feeding PV inputs, but with either lithium or rectified AC I'd want current limit.

 

[underdog5004]

I remember reading a thread, here or elsewhere, where OP had a prius with 220vdc battery, was able to use a midnite classic 250 (cp? Some special model that was discontinued(?)) with a custom amp/volt curve (like for hydro or wind? Idk) to efficiently move power from his prius to his house power bank. Said gas consumption was on par with a Honda 2000 generator.

Look up "prius solar midnite" I'm sure it'll come up.

Edit: OK I won't be lazy - https://www.solarpaneltalk.com/foru...idnight-classic-as-voltage-converter-possible

 

[KenN2]

Hey guys,
Does anyone know how the MPPT circuitry in an inverter would handle fixed DC voltage instead of the input from solar panels?
I'm wondering if I can connect a 350-400v EV battery to the solar input of an inverter.
The DC voltages are in the same range so technically the 5000w inverter would only pull around 13A from the EV pack to max out it's AC output.

Would this work or is it a recipe for magic smoke ?

Check out https://www.ampernext.com/products/first-30kw-dc-dc-solar-ev-charger/

 

[sunshine_eggo]

Not an endorsement:

HOME | PlugOut Power, Generator for hybrid vehicles | United States

Hybrid and plug-in vehicles can become power generators for the home using the PlugOut inverter.

www.plugoutpower.com

 

[Hedges]

Success: Powering a skillsaw from Prius battery connected to PV input (with automotive starting batteries to supply surge)

UTILIZING GRID TIE INVERTER OFF GRID - $100 REWARD FOR SOLUTION

Get the LA batteries fully charged. They can deliver some 400 ~ 700 cranking amps (which is at a rather low voltage.) 5kW/50V = 100A, not much for a car battery. Review low battery settings. Did it display a reason for cutout? Does it have a time delay for low battery? I'd want to let it drop...

diysolarforum.com

 

[sunshine_eggo]

OMG... glad when that thread ended.

 

[Crowz]

OMG... glad when that thread ended.

Nice seeing the tp6048 I have being the winning solution

 

[DIYrich]

I remember reading a thread, here or elsewhere, where OP had a prius with 220vdc battery, was able to use a midnite classic 250 (cp? Some special model that was discontinued(?)) with a custom amp/volt curve (like for hydro or wind? Idk) to efficiently move power from his prius to his house power bank. Said gas consumption was on par with a Honda 2000 generator.

Look up "prius solar midnite" I'm sure it'll come up.

Edit: OK I won't be lazy - https://www.solarpaneltalk.com/foru...idnight-classic-as-voltage-converter-possible

I have 2 hybrid cars. Similar in theory to a Prius. Hmm....

 

[Crowz]

Remember that guy was using a dead hybrid for power. Considering how fragile the things are I wouldn't tinker with one that ran and or you want to keep running

 

[Vigo]

Fragile?! I sold my 07 Prius with 279k to my father in law who still has it at just over 400k. I put a timing chain set and maybe crank bearings in it at 300-something thousand. Original battery as far as i know, although obviously degraded it doesn't fault out and the car still works and gets high-30s mpg (down from almost 50 originally). I've done the odd repair here and there but the 2nd gen and newer prii are some of the most reliable vehicles on the planet. I wouldn't call them fragile!

This is coming from an ASE Master Tech who teaches automotive at community college, but still, opinions are opinions, take it for what it's worth.

I wouldn't be surprised if newer stuff would notice the 'missing energy' and need workarounds, but to my knowledge an old Prius won't.

I am still planning to do with with an 01 Honda Insight i have sitting around broken down. That's a 144vdc nominal system. I drove that thing up to 347k. That one i would say is fragile in terms of the original battery design. But that's more of a longevity than a durability thing so fragile still might not be the right word.

 

[yabert]

Does anyone know how the MPPT circuitry in an inverter would handle fixed DC voltage instead of the input from solar panels?
I'm wondering if I can connect a 350-400v EV battery to the solar input of an inverter.

Yes it can. At least with my cheap PowMr inverter.
I did with the 360V battery of my Chevy Bolt (well, a Vanabolt). Details here: https://diysolarforum.com/threads/360v-dc-input-split-phase-120v-240v-ac-inverter.15036/page-4
About inrush current, there is not. Simply connect your inverter and start your EV after. That manner the precharge is done by the EV and there is no inrush to the inverter who simply become another high voltage parts of the EV with the motor controller, DC-DC, charger, heater, AC compressor.

 

[Vigo]

Generally speaking an MPPT will not have much 'inrush' anyway because they always start as a high resistance and then work their way down when seeking the max power point, so when initially hooking a power source to an mppt any inrush is constrained by that in the first place. What i would not do is hook a new power source in parallel with an mppt that is already managing a different power source, because there is no guarantee it will not briefly over-current in that scenario.

I have also fed rectified/filtered mains into MPPT as well and had no problems so far. ?

 

[sunshine_eggo]

Fragile?! I sold my 07 Prius with 279k to my father in law who still has it at just over 400k. I put a timing chain set and maybe crank bearings in it at 300-something thousand. Original battery as far as i know, although obviously degraded it doesn't fault out and the car still works and gets high-30s mpg (down from almost 50 originally). I've done the odd repair here and there but the 2nd gen and newer prii are some of the most reliable vehicles on the planet. I wouldn't call them fragile!

Revised for accuracy. The Gen3 eat engines and batteries.

This is coming from an ASE Master Tech who teaches automotive at community college, but still, opinions are opinions, take it for what it's worth.

I have no certifications, but I have personally worked on 500+ Toyota hybrids, and I collaborate with multiple hybrid specialty shops in four locations across the country. The Gen3 are a scourge on the name. Gen4 and newer seem to have sorted the engine issues at least.

The 2023... now that looks pretty luscious...

I am still planning to do with with an 01 Honda Insight i have sitting around broken down. That's a 144vdc nominal system. I drove that thing up to 347k. That one i would say is fragile in terms of the original battery design. But that's more of a longevity than a durability thing so fragile still might not be the right word.

Don't you know it. Honda sticking with the "D" cell package was a horrific mistake that they took to an even greater level with the 06-08 (1 in six failures in 5-7 years) and then again with the 09-11 (1 in three failures in 2-4 years) Civic. I just sold an '05 G1 Insight in December and still have an '02 on the back porch waiting for some love. Yep... both needed batteries.

 

[Vigo]

Thanks for the perspective on the gen3s. Unfortunately i never got to work on them (i probably stopped working in shops before they all started breaking out of warranty) and i dont have any contacts in repair industry who deal with them constantly, nor have i personally researched very much into them. So i definitely bow to your greater experience there.

 

[sunshine_eggo]

Thanks for the perspective on the gen3s. Unfortunately i never got to work on them (i probably stopped working in shops before they all started breaking out of warranty) and i dont have any contacts in repair industry who deal with them constantly, nor have i personally researched very much into them. So i definitely bow to your greater experience there.

You have my sympathies on the Insight. When it comes time to replace the battery, I recommend Matt with HybridRevolt in the Phoenix, AZ area. Mostly a one man show, but he does great work, and he's been at it 10+ years. His communication and customer service is notoriously lacking, thus requiring multiple follow-ups on your part, but the quality of his output is the best in the country.

If you want to pursue your own battery refurb, or a DIY grid charger, I can provide guidance. In the '05 I sold, I had an on-board grid charger installed inside the battery that simply needed an extension cord.

 

[Vigo]

I am debating how to get it back up and running. I have a whole second pack worth of used cells but at this point ALL of them have been sitting neglected for years straight. I ended up with a 0-300vdc medical power supply i have used as a 'grid charger' in the past, but if i ever do get this project idea rolling i'll probably look into a more permanent solution. Thanks for the offer, I will definitely hit you up if and when i make actual moves. First one will be making it have fuel pressure again so i can start it and move it around, but i'll leave you out of that inanity.

 

[sunshine_eggo]

I am debating how to get it back up and running. I have a whole second pack worth of used cells but at this point ALL of them have been sitting neglected for years straight. I ended up with a 0-300vdc medical power supply i have used as a 'grid charger' in the past, but if i ever do get this project idea rolling i'll probably look into a more permanent solution. Thanks for the offer, I will definitely hit you up if and when i make actual moves. First one will be making it have fuel pressure again so i can start it and move it around, but i'll leave you out of that inanity.

I assume you're referring to an electrophoresis power supply. I have like 6 of them.

The good news is that the deep discharge experienced by the panasonic cells are actually restorative. It completely obliterates capacity loss due to voltage depression when they're sitting at 0.8V/Cell or less. if they're holding > 1.2V/cell, they're definitely good.

I'll shoot you a PM. There are diagnostic steps you can take right now on the spare pack to weed out bad ones.