Reply
 
Thread Tools Search this Thread Display Modes
 
Old 10-31-2016, 10:41 AM   #1
Senior Member
 
Ka_sea_ta's Avatar
 
City: Puget Sound
Country: USA
Join Date: Jun 2016
Posts: 295
Powerwall 2 14 kwh with inverter < $6k

Tesla announced powerwall2 pricing of $5500 for 14kw battery bank with an inverter. Seems to me a factory reconfiguration of the battery pack to 12vdc would provide an ideal house battery for boats and RVs... Obviously the bank could be scaled for smaller load demands... Cool stuff.
__________________
Advertisement

Ka_sea_ta is offline   Reply With Quote
Old 10-31-2016, 11:13 AM   #2
Guru
 
djmarchand's Avatar
 
City: Litchfield, Ct/Punta Gorda, Fl
Country: USA
Vessel Model: Atlas Pompano 23- outboard
Join Date: Aug 2012
Posts: 3,858
That price is getting better, but 14 kw is really way too big for a house bank.


14 kw is about 1,200 Ahs at 12v. One of the selling points of a lithium battery system is that it can be routinely discharged to near zero and easily recharged to 100% unlike FLAs.


FLAs really effectively cycle between 50 and 85% whereas lithiums probably can be cycled between 10 and 100%, giving almost three times the effective capacity.


So a 1,200 FLA bank which would be rather big for a boat system is equivalent to a 400 Ah lithium bank. If the cost of a 400 Ah lithium bank is near 1/3 the cost of a 1,200 Ah bank then it is getting much closer to the cost of FLAs.


AGMs supposedly can be discharged deeper than FLAs, but I haven't seen any manufacturer data to back that up. But if true and assuming a 30-90% cycle, the lithium bank is even more competitive with AGMs.


I never thought I would see the day that lithiums would compete for the marine house bank business, but it is getting closer it seems.


David
__________________

djmarchand is online now   Reply With Quote
Old 10-31-2016, 12:34 PM   #3
Senior Member
 
Jeff F's Avatar
 
City: London, ON
Country: Canada
Vessel Model: Mainship 34 Original
Join Date: Nov 2015
Posts: 469
Quote:
Originally Posted by djmarchand View Post

I never thought I would see the day that lithiums would compete for the marine house bank business, but it is getting closer it seems.

David
I read an article this morning where an automaker was quoted at saying their cost for Lithium Ion batteries is now down to $145/kWh. When I bought my EV under three years ago the cost was reported to be more than double that. Still lots of concerns over battery management and risk of heat/fire, but the rapid progress on resolving these issues is going to continue.
Jeff F is offline   Reply With Quote
Old 10-31-2016, 03:43 PM   #4
Guru
 
Brooksie's Avatar
 
City: Cape Cod, MA
Country: USA
Vessel Name: Island Seeker
Vessel Model: Willard 36 Sedan
Join Date: Oct 2007
Posts: 988
Quote:
Originally Posted by djmarchand View Post
I never thought I would see the day that lithiums would compete for the marine house bank business, but it is getting closer it seems.
David
If you have ever been involved is a fire at sea, lithiums would be a last choice to have aboard.
Brooksie is offline   Reply With Quote
Old 11-06-2016, 11:41 PM   #5
Guru
 
sbu22's Avatar
 
City: New Orleans
Country: US
Vessel Name: Panache
Vessel Model: Viking 43 Double Cabin '76
Join Date: Mar 2011
Posts: 926
What Brooksie said. I don't see the average boat owner adding Class D extinguishers. Will that be in copper, graphite, TEC, or THD, Captain? I think the rec boat application is still well over the horizon.
sbu22 is offline   Reply With Quote
Old 11-07-2016, 01:41 AM   #6
Guru
 
Simi 60's Avatar
 
City: Queensland
Country: Australia
Vessel Model: Milkraft 60 converted timber trawler
Join Date: Jul 2016
Posts: 1,556
Quote:
Originally Posted by djmarchand View Post
That price is getting better, but 14 kw is really way too big for a house bank.


14 kw is about 1,200 Ahs at 12v. One of the selling points of a lithium battery system is that it can be routinely discharged to near zero and easily recharged to 100% unlike FLAs.

Sounds about right for me.
I have 8 x 220ah @ 12v = 1760 now
so 880ah @ 24v giving 2 days autonomy.

A couple of days extra wouldn't go astray, I could piss off this puny 3 burner smev gas oven and get in a decent sized electric oven in its place.

Unfortunately, your $5500 there will be more like $20,000 here.
__________________

Simi 60 is online now   Reply With Quote
Reply

Thread Tools Search this Thread
Search this Thread:

Advanced Search
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off





All times are GMT -5. The time now is 10:11 PM.


Powered by vBulletin® Version 3.8.8 Beta 4
Copyright ©2000 - 2018, vBulletin Solutions, Inc.
Search Engine Optimization by vBSEO 3.6.0
Copyright 2006 - 2012