On 5/19/19 5:25 PM, Bruce Layne wrote:
On 5/19/19 6:01 PM, Kirk Wallace wrote:
There are a lot of surplus Leaf batteries available. My opinion on
these is that these were removed for warranty replacement due to
overheating. These are air cooled and don't do well if they are
rapid charged more than once during long trips. I am tending to
avoid these.
I saw those Nissan Leaf batteries as related eBay links. The price
per energy storage looked very good. I assumed these were some sort
of warranty replacement batteries, but didn't search to learn the
reason these are on the surplus market.
Vendors don't seem to be too keen on providing information on their
batteries. Either they don't know, don't understand what they have, or
choose not to share. BatteryHookup.com seems to be the best DIY battery
vendor so far. My opinion on Leaf batteries is based on the RapidGate
chatter, where rapid charging was slowed way down on the second charge
which you don't want to learn about in the middle of a long trip.
https://www.youtube.com/watch?v=Dpwyue9IiBE
I vaguely recall hearing of technical problems with the Nissan Leaf. If the problem was
overheating when fast charging or discharging in a car, that
wouldn't deter me from using them in an off-the-grid home. It
probably wouldn't be an issue in a properly sized system, and the
Nissan batteries could easily be mounted vertically with air gaps and
even inexpensive heat sinks could be used to accentuate cooling.
For properly sized stationary batteries I don't think the battery will
come close to working hard enough to even get warm. It would be nice if
vendors would test cells or battery capacity and post this in their ads.
Testing is likely to be expensive so there isn't much incentive for
testing if one is selling cells well enough anyway.
I'd need to research the cell balancing and battery management as
that's critical. A lot of those electronics are built into the
Tesla battery packs which sounds good, but it's proprietary so using
them in a home requires the batteries to be fooled into thinking
they're in a car. An entrepreneur makes a device to do that. Jack
Rickard of EVTV.
The $1200 class batteries are for a module within the battery pack, so
it is just ~5 kWh(?) of 18650 cells and no electronics. In my view
balancing isn't nearly as important as monitoring which is much easier
to do with off-the-self products.
http://store.evtv.me/proddetail.php?prod=1FullpackController
I sent links earlier in this thread to a friend who used a Tesla
battery for his off-the-grid home, and he displays battery life in
odometer miles. I think he largely does this for a lark and he
displays more conventional units as well, but keeping it in terms of
miles, even though not applicable to a house, does provide a battery
life indication that compares well to the original automotive use. No
doubt he'll get more "miles" from his off the grid batteries than
they'd get in a car where they're typically charged and discharged
at a faster rate.
Part 3 of the series, where the custom battery monitoring is
demonstrated: https://www.youtube.com/watch?v=AIY2EWke-AA
On 5/19/19 6:07 PM, andy pugh wrote:
(And, while we are at it, kWh is a horrible unit. What is wrong
with MJ? )
Kilowatt hours is easier for me to convert into miles. :-)
An American arguing with an Englishman over the metric system is
funny. You guys invented this crummy system. Just because you were
smart enough to switch to the metric system and we're still stuck on
stupid is no call for being cheeky. :-P
- and there is no such word as "maths".
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