Count your kWh...

[Shayne]

Yes, there's a strong market for BEV battery packs retired from service due to accidents or even an inability to hold a full charge. Even when it won't hold enough power for automotive use the pack has lots of life backing up homes or server farms.

I caught it no misunderstanding at all. Storage off peak for peak is not a new idea. Look at Australia power and tesla. Beats dumping it to ground and if you research the environmental impact of you buying a 100 KWh battery after stationary they can be recycled.

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[Scarpia]

I think you misunderstood me. Yes homes need batteries to reduce the strain on the grid, but they don't have to be lithium-ion - they can be any chemistry since weight isn't a factor. Lead-acid or some other cheaper, more available formulation so it doesn't take away from li-ion production for cars.

Ah yes, that wasn't clear to me, sorry. I believe the reason Li-ion batteries are used is because of the same advantages they bring to cars (lifespan, power, etc.), but it would be interesting to compare the tradeoffs with other battery types.

 

[ChasingCoral]

I'd like to discourage using that large of an inverter, the DC-DC converter can only output 160A MAX under optimal conditions, which is under 2000W. It would be foolish to draw more than 1000W and risk burning out the DC-DC module. Also sloppy using unprotected jumper cables an inch apart from each other. Short those by accident and you'll probably be stranded and looking at a $1500+ repair bill that isn't covered by warranty due to misuse. Too much expensive hardware at stake here.

Bring a generator next time.

I purchased a 1000W inverter to do this job using our Leaf. You could probably use as much as a 1500W on the Mach E as it has a peak delivery of 1920w through the DC-DC inverter.

 

[dtbaker61]

I'd like to discourage using that large of an inverter, the DC-DC converter can only output 160A MAX under optimal conditions, which is under 2000W. It would be foolish to draw more than 1000W and risk burning out the DC-DC module. Also sloppy using unprotected jumper cables an inch apart from each other. Short those by accident and you'll probably be stranded and looking at a $1500+ repair bill that isn't covered by warranty due to misuse. Too much expensive hardware at stake here.

Bring a generator next time.

jumper cables to designated 12v 'connection points' are obviously a temporary test connection.... Anderson connectors or something similar will be a more dependable/safer connection, but will require removal/modification of the 'beauty cover' and installation of better connectors.

an 'oversize' inverter shouldn't harm anything as long as continuous export is less than 2000 watts and the dc-dc can 'keep up'. Since the recharge of the LVB is thru a circuit breaker, and the dc-dc presumably has some max output designed to run all the big stuff like the cabin and battery heat pumps for extended periods. I would love to get some confirmation on the 160amp limit, where did you see it documented?

What I did find is that for loads over about 1000watts, it is best to put a second battery in parallel to prevent the voltage sagging down below what the inverter is happy with before the dc-dc kicks in, or 'start' the car or begin with a smaller load to wake up the dc-dc before hitting the little battery with a big load.

why would I want to bring and run a gas generator when I have 60+ kWhr of battery available ?!

 

[ChasingCoral]

I would love to get some confirmation on the 160amp limit, where did you see it documented?

See post above yours.

 

[dtbaker61]

Ah yes, that wasn't clear to me, sorry. I believe the reason Li-ion batteries are used is because of the same advantages they bring to cars (lifespan, power, etc.), but it would be interesting to compare the tradeoffs with other battery types.

LFP, (LiFePO4) 'large format prismatic' cells are being used more in stationary battery backup. Larger format (100ah-200ah) per cell means few connections and the electrolyte 'goo' inside is far less flammable that the typical Li-ion cell.... much less likely to go into thermal runaway even when overcharged by a bad charger, or BMS failing to top balance and end charge when the first cell hits programmed limit voltage. They also typical are designed to vent rather than vaporize the goo and burst into flame if charged over-voltage/over temp.

 

[dtbaker61]

See post above yours.

aha, I didn't see that till I refreshed my browser.
Any idea what document that came from ? I'd like to get my hands on the specs for the dc-dc, and the suggested repair/replacement procedures for access to the HV fuses/circuit breakers.

 

[ChasingCoral]

aha, I didn't see that till I refreshed my browser.
Any idea what document that came from ? I'd like to get my hands on the specs for the dc-dc, and the suggested repair/replacement procedures for access to the HV fuses/circuit breakers.

It's from one of the Ford maintenance/specification documents accessible to folks inside Ford or those with maintenance licenses.

 

[dtbaker61]

Yes, there's a strong market for BEV battery packs retired from service due to accidents or even an inability to hold a full charge. Even when it won't hold enough power for automotive use the pack has lots of life backing up homes or server farms.

absolutely true....

BUT, the dangers are using a 48v pack cobbled together with chunks of used cells with unknown capacity and state of charge without re-balance before charge/use, and having some strategy or BMS in place to let you know when cells become unbalanced or fail.


Before re-packaging used Lithium cells.... they should be tested and put in strings with 'matching' capacity and internal resistance, individually top-balanced before full series charge, and monitoring in some way to maintain end of charge voltage as they drift apart over time and charge cycles.

 

[AZBill]

I caught it no misunderstanding at all. Storage off peak for peak is not a new idea. Look at Australia power and tesla. Beats dumping it to ground and if you research the environmental impact of you buying a 100 KWh battery after stationary they can be recycled.

You mean this battery storage site that caught fire?

https://news.yahoo.com/australia-tesla-battery-blaze-under-072810881.html

 

[timbop]

I recently read an article about lithium battery reuse/recycling.
In the article, they made a use case for reusing EV batteries for stationary use. One your EV battery gets to a point where it’s only 60-70% capacity of when it was new, it may make sense to continue using it for PV installations. If you want 50 KwH of battery capacity for a solar application, a 75 KwH battery that is depleted to 70% capacity will do fine. In most stationary installations, a little extra bulk won’t be an issue.
Environmentally, it would make more sense to keep using the battery instead of recycling at that point in its life.

Yes, there's a strong market for BEV battery packs retired from service due to accidents or even an inability to hold a full charge. Even when it won't hold enough power for automotive use the pack has lots of life backing up homes or server farms.

Yes, I am aware of that use case and it very much makes sense - but the kind of scale necessary to get as many people on solar with battery backups (to take strain off of the grid) as possible means far more new batteries vs recycled car batteries. Li-ion production is already the constraint for getting more BEV's on the road for quite some time, so I'd rather we don't add to the bottleneck.

You mean this battery storage site that caught fire?

https://news.yahoo.com/australia-tesla-battery-blaze-under-072810881.html

And this is another reason a different chemistry might be better

 

[Maquis]

Yes, I am aware of that use case and it very much makes sense - but the kind of scale necessary to get as many people on solar with battery backups (to take strain off of the grid) as possible means far more new batteries vs recycled car batteries. Li-ion production is already the constraint for getting more BEV's on the road for quite some time, so I'd rather we don't add to the bottleneck.

Correct - that's true right now. But I'd bet that in 20 years (maybe less), reused EV batteries will be able to supply nearly all of the demand for residential solar storage.

 

[Shayne]

You mean this battery storage site that caught fire?

https://news.yahoo.com/australia-tesla-battery-blaze-under-072810881.html

It is not generating it it is storing it for demand that needs to be studied. Did you see the mirror collector and the brine storage?

 

[bruceski88]

I have a snow rake but 50% of my panels are on top of a 2 story house. There is no way I am going up there at my age. It works for the 1 story garage roof but quite often we get freezing rain followed by snow.

Buy 2 of or some extra poles. I can reach 40’ from the ground. Great shoulder exercise.

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