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[GMCnet] Inverter and converter....how about both? [message #347597] Mon, 09 September 2019 19:17 Go to next message
glwgmc is currently offline  glwgmc   United States
Messages: 1014
Registered: June 2004
Karma: 10
Senior Member
Hi John,

Be very careful doing anything with Tesla or any other car batteries! There is a lot of voltage and a lot of amperage there - way, way more than the 12vdc nominal you want for a house bank in your GMC. The battery chemistry is also way wrong and potentially dangerous for use as a house battery bank without all the sophisticated battery management and cooling built into those batteries for use in the Tesla cars. Tesla is now in its third generation battery technology. The cells look a lot alike, but are no where near the same internally from one generation to the next. The original model S battery bank is made up of over 7000 18650 size cells welded into precisely shaped bricks that are connected series/parallel and surrounded by active liquid cooling. The model 3 batteries are made from more than 4000 cells of a different battery chemistry and a different 21700 size cell made by Panasonic that will become the standard for all Tesla offerings from here on. Panasonic uses various blends of cobalt in their cells to get greater energy density but which also involve greater thermal runaway - fire- risks unless managed very actively by both the Tesla battery management systems and their active heating and cooling systems. Yes, for cold weather use the batteries get heated by a form of miniature heat pump designed just for this purpose. For warm weather use the battery cooling fluid is passed through a special part of the AC system output to keep the batteries from over heating.

For use as a house battery bank for your GMC you want ONLY Lithium Iron Phosphate chemistry built to a 12vdc nominal battery by a reputable company with a properly designed, built-in on-board battery management system made for and by the company that built the battery in the first place. Back yard tinkering here can be dangerous to your body parts and loved ones

Jerry
Jerry Work
The Dovetail Joint
Fine furniture designed and hand crafted in the 1907 former Masonic Temple building in historic Kerby, OR

glwork@mac.com
http://jerrywork.com

==========Message: 7
Date: Mon, 9 Sep 2019 14:50:15 -0700
From: John Phillips
To: gmclist@list.gmcnet.org
Subject: Re: [GMCnet] Inverter and converter....how about both?
Message-ID:

Content-Type: text/plain; charset="UTF-8"

Vern,
Did you remove your roof AC units?
What kind of racking system did you use?
I would not like to have a panel come off while driving.
I have 8 Solarworld 315 watt 39x78 inches 50 lbs panels I have been
thinking of putting on top of my GMC. It would be nice if I could figure a
way to use some of them as lids for cargo pods.
Reclaimed Tesla car models available on eBay look like a good choice for
batteries. That should be enough to run some AC in the form of a miny split
with soft-start. The panels would have to be mounted high enough to be over
the vents.
I have not figured out where to mount the min split but the efficiency gain
and lowering the roofline rather than having the panels over the AC units
would be worth something. Would this mod make it look too much like a
camper?
I do a lot of dreaming and not much action. I may never do it but I have
been thinking about this for a while now.

John Phillips
75 Avion VIN A26000
Retired
Rancho Cordova, CA 95670
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Jerry & Sharon Work
78 Royale
Kerby, OR
Re: [GMCnet] Inverter and converter....how about both? [message #347647 is a reply to message #347597] Tue, 10 September 2019 16:37 Go to previous messageGo to next message
johnd01 is currently offline  johnd01   United States
Messages: 354
Registered: July 2017
Location: Sacrameot
Karma: -1
Senior Member
I was looking at Tesla Battery Module 24V 250Ah 5.2 kWh 444 Panasonic 18650
Cells battery for $1200, not the entire Tesla battery system. It is a
24-volt system capable of a lot more current than GMC would need or my
solar could charge. I have not selected a charge controller but 24-volt
solar storage systems are quite common. Coupled to a 24-volt pure sign
inverter the system could replace the Onan. I would still keep the deep
discharge battery I have upfront but remove the 2 6volt golf cart
batteries in the back. When the 120/240 V inverter is on it would use the
present charging system to top off the front battery. I would not push the
Tesla battery nearly as hard as it is designed to need the cooling system.
It would take more than 8 GC2 batteries to store as much as energy as one
Tesla module. I may need 2 Tesla module and build a 48-volt system with
something like an Outback Power FLEXmax FM60 MPPT Solar Charge Controller
which could handle 2 4 panel stings of 315-watt panels.

On Mon, Sep 9, 2019 at 5:17 PM Gerald Work via Gmclist <
gmclist@list.gmcnet.org> wrote:

> Hi John,
>
> Be very careful doing anything with Tesla or any other car batteries!
> There is a lot of voltage and a lot of amperage there - way, way more than
> the 12vdc nominal you want for a house bank in your GMC. The battery
> chemistry is also way wrong and potentially dangerous for use as a house
> battery bank without all the sophisticated battery management and cooling
> built into those batteries for use in the Tesla cars. Tesla is now in its
> third generation battery technology. The cells look a lot alike, but are
> no where near the same internally from one generation to the next. The
> original model S battery bank is made up of over 7000 18650 size cells
> welded into precisely shaped bricks that are connected series/parallel and
> surrounded by active liquid cooling. The model 3 batteries are made from
> more than 4000 cells of a different battery chemistry and a different 21700
> size cell made by Panasonic that will become the standard for all Tesla
> offerings from here on. Panasonic uses various blends of cobalt in their
> cells to get greater energy density but which also involve greater thermal
> runaway - fire- risks unless managed very actively by both the Tesla
> battery management systems and their active heating and cooling systems.
> Yes, for cold weather use the batteries get heated by a form of miniature
> heat pump designed just for this purpose. For warm weather use the battery
> cooling fluid is passed through a special part of the AC system output to
> keep the batteries from over heating.
>
> For use as a house battery bank for your GMC you want ONLY Lithium Iron
> Phosphate chemistry built to a 12vdc nominal battery by a reputable company
> with a properly designed, built-in on-board battery management system made
> for and by the company that built the battery in the first place. Back
> yard tinkering here can be dangerous to your body parts and loved ones
>
> Jerry
> Jerry Work
> The Dovetail Joint
> Fine furniture designed and hand crafted in the 1907 former Masonic Temple
> building in historic Kerby, OR
>
> glwork@mac.com
> http://jerrywork.com
>
> ==========Message: 7
> Date: Mon, 9 Sep 2019 14:50:15 -0700
> From: John Phillips
> To: gmclist@list.gmcnet.org
> Subject: Re: [GMCnet] Inverter and converter....how about both?
> Message-ID:
> CANEyv6aYdnk0Atw0q6aFG23s63iOK9iuH-S4As8cb_Vkf05vDg@mail.gmail.com>
> Content-Type: text/plain; charset="UTF-8"
>
> Vern,
> Did you remove your roof AC units?
> What kind of racking system did you use?
> I would not like to have a panel come off while driving.
> I have 8 Solarworld 315 watt 39x78 inches 50 lbs panels I have been
> thinking of putting on top of my GMC. It would be nice if I could figure a
> way to use some of them as lids for cargo pods.
> Reclaimed Tesla car models available on eBay look like a good choice for
> batteries. That should be enough to run some AC in the form of a miny split
> with soft-start. The panels would have to be mounted high enough to be over
> the vents.
> I have not figured out where to mount the min split but the efficiency gain
> and lowering the roofline rather than having the panels over the AC units
> would be worth something. Would this mod make it look too much like a
> camper?
> I do a lot of dreaming and not much action. I may never do it but I have
> been thinking about this for a while now.
>
> John Phillips
> 75 Avion VIN A26000
> Retired
> Rancho Cordova, CA 95670
> =========
>
>
>
>
>
>
>
> _______________________________________________
> GMCnet mailing list
> Unsubscribe or Change List Options:
> http://list.gmcnet.org/mailman/listinfo/gmclist_list.gmcnet.org
>


--

*John Phillips*
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Johnd01 John Phillips Avion A2600 TZE064V101164 Rancho Cordova, CA (Sacramento)
Re: [GMCnet] Inverter and converter....how about both? [message #347648 is a reply to message #347597] Tue, 10 September 2019 16:47 Go to previous messageGo to next message
ljdavick is currently offline  ljdavick   United States
Messages: 3548
Registered: March 2007
Location: Fremont, CA
Karma: -3
Senior Member
Interesting idea. The website Teslarati has a small write up about someone doing this
https://www.teslarati.com/install-tesla-battery-solar-rv-lifestyle/
<https://www.teslarati.com/install-tesla-battery-solar-rv-lifestyle/>

The future looks pretty good!


Larry Davick
A Mystery Machine
1976(ish) Palm Beach
Fremont, Ca
Howell EFI + EBL + Electronic Dizzy
Re: [GMCnet] Inverter and converter....how about both? [message #347651 is a reply to message #347648] Tue, 10 September 2019 18:40 Go to previous messageGo to next message
Vern Crawford is currently offline  Vern Crawford   United States
Messages: 81
Registered: August 2016
Karma: -1
Member
Howdy Larry, and anyone else curious about what I would incorporate in a
"possible" future solar build,

Regarding the mounting of the panels, this was an opportunity to compare
actual panels against one another. The seven panels were purchased from
five different sources and all are slightly different. Also I purchased
several different mounting systems, plus designed several from hardware
readily available locally. All systems that were attached directly to the
GMCs roof include 3M VHB double sided adhesive tape, and secured with self
taping screws. I adapted or designed all mounting assemblies to allow the
possibility of adjusting the angle to optimize harvesting the sun's rays
when boon-docking for extended times. All panels are mounted at 4 points
and have proven to be extremely secure. After over 25,000 miles of highway
speeds and with regular inspections before major excursions, confirming
just how secure they are attached insures no fear of anything coming loose
while rolling down the road.

If I were to start over from scratch on a different coach the build would
be certainly be different. Not because of any dissatisfaction with what I
have now, which has well met all of our expectations, but to prove that
today solar on a small coach is capable of meeting the energy needs for
most owners, in almost any climate. For solar to include air conditioning,
one simply needs to build a system properly sized and "make ice while the
sun shines!"

What changes and improvements would I make based on what I've learned thus
far?

I would start with a solid coach that has already had extensive
refurbishing, both mechanically and cosmetically, especially maximizing the
R-value in floors, walls, and ceiling.

Then, rather than the hodgepodge of seven single 12 volt panels fitted to
seven various adaptable locations, I'd build-up a solid durable aluminum
frame to interlock 8 identical 48 volt residential panels, designed to
mount to roof railings such that the entire assembly could be adjusted for
optimal harvesting of the sun's rays if desired for longer term
boon-docking, while at the same time shading the majority of the roof from
the direct heat of the sun. Such an eight panel assembly would measure
just under 21 foot in length by 7 foot width, rated at over 2,500 watts
potential input. I would also increase my energy storage from 500 Ah
LiFePo4 to 800 Ah, increase the charge controller to at least 100A, and
upgrade the 2000w pure sine wave inverter to 4,000w.

Replacing the old inefficient roof A/C unit with a more modern soft start
European mini-split system would allow a lifestyle permitting the coach to
be successfully cooled in the heat of the desert to a more comfortable
level during the heat of the day. There is simply no comparison to the old
roof top units that typically are on our old coaches. The efficiency range
of the mini split units usually fall somewhere between 20 to 30+ SEER, and
should be easily adaptable to our coaches.

Our current installation actually cost us right at $7,000 total, plus a
wee-bit of "sweat" equity. The maxed out "ideal" install should come in
at +/- $12,500, plus a wee-bit more of that "sweat" equity.

All I need is that second GMC coach. But right now we are having so much
fun with what we have!

Here's a link to my DropBox file with a wiring diagram and a few pictures
of our system:
https://www.dropbox.com/sh/r3eoxavcqrulcb9/AABssB0dNMOTu3bKl-EiyUhra?dl=0

Hugs,
Vern, Lenore, and Knibbles D. Kat


On Tue, Sep 10, 2019 at 4:48 PM Larry Davick via Gmclist <
gmclist@list.gmcnet.org> wrote:

> Interesting idea. The website Teslarati has a small write up about
> someone doing this
> https://www.teslarati.com/install-tesla-battery-solar-rv-lifestyle/
>
>
> The future looks pretty good!
> --
> Larry Davick
> A Mystery Machine
> 1976(ish) Palm Beach
> Fremont, Ca
> Howell EFI + EBL + Electronic Dizzy
>
> _______________________________________________
> GMCnet mailing list
> Unsubscribe or Change List Options:
> http://list.gmcnet.org/mailman/listinfo/gmclist_list.gmcnet.org
>


--
Vern Crawford (and Lenore Langsdorf)
155 JJ Lane
Center Point, TX 78010
(618) 203-8296 Vern's cell
(830) 928-5550 Lenore's cell
VernCrawford@GMail.Com
LenoreLangsdorf@GMail.Com
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Re: [GMCnet] Inverter and converter....how about both? [message #347655 is a reply to message #347651] Tue, 10 September 2019 20:23 Go to previous message
ljdavick is currently offline  ljdavick   United States
Messages: 3548
Registered: March 2007
Location: Fremont, CA
Karma: -3
Senior Member
Maybe someday we’ll be able to roll out an awning of solar panels too!

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Larry Davick
A Mystery Machine
1976(ish) Palm Beach
Fremont, Ca
Howell EFI + EBL + Electronic Dizzy
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