Tesla Powerwall Chemistry vs Tesla Powerpack Chemistry

[fromport]

I was reading an article on the differences between the Tesla Powerwall and the Tesla Powerpack

From the article:

Musks mentiones that there are indeed different chemistries in the two Tesla Energy products.
The backup power option, the Powerpack, is quite similar to that in the Tesla Model S and X, using a nickel-cobalt-aluminum cathode.
The daily cycling option, the Powerwall, is made of nickel-manganese-cobalt (with “quite a lot of manganese in there”).
The first is meant for ~60–70 cycles per year, and the other one for 365 cycles a year.
Tesla expects the Powerwall to last for approximately 15 years, ~5,000 cycles (but with the warranty being 10 years).
The Powerpack is expected to last for, “depending on how it’s used, anywhere from 1,000 to 1,500 cycles.” And they have comparable calendar lives.

So the batteries in a Tesla (derivative) aren't supposed to be charged/discharged on a daily basis ?
Or do I interpret that wrong ?

Source of article: http://cleantechnica.com/2015/05/07...s-in-under-a-week-tesla-elon-musk-transcript/

 

[miimura]

So the batteries in a Tesla (derivative) aren't supposed to be charged/discharged on a daily basis ?
Or do I interpret that wrong ?

Tesla does not anticipate car owners doing full charge/discharge every day. Shallow cycles are not nearly as hard on the battery. With this kind of grid connected battery, it would be easy to fully discharge it every day. The 7kWh PowerWall Daily Cycling model has the same chemistry as you described for the PowerPack. The 10kWh PowerWall model is described as the "back up power" model.

I'm not that hot on this high voltage DC architecture. I'm sure it's good for new installations, but it doesn't fit at all with what I have already. It's also a departure from the Beta Test systems that they already have in the field. Those used a conventional 48VDC nominal pack and a standard Off-Grid architecture. If I do a battery system, I will probably use a standard 48VDC system that I can control myself. Using salvaged automotive lithium ion cells with a larger capacity for backup and shallow cycles for daily demand shifting should have a long life.

 

[fromport]

Tesla does not anticipate car owners doing full charge/discharge every day. Shallow cycles are not nearly as hard on the battery. With this kind of grid connected battery, it would be easy to fully discharge it every day. The 7kWh PowerWall Daily Cycling model has the same chemistry as you described for the PowerPack. The 10kWh PowerWall model is described as the "back up power" model.
[/qoute]
I certainly discharge/charge my EV every day and I think most people do.
Not 100% or even 80% probably but I've done 5 QC sessions on one day.
I assume people who take a tesla model S on a long trip charge more then once per day.


[qoute]
I'm not that hot on this high voltage DC architecture. I'm sure it's good for new installations, but it doesn't fit at all with what I have already. It's also a departure from the Beta Test systems that they already have in the field. Those used a conventional 48VDC nominal pack and a standard Off-Grid architecture. If I do a battery system, I will probably use a standard 48VDC system that I can control myself. Using salvaged automotive lithium ion cells with a larger capacity for backup and shallow cycles for daily demand shifting should have a long life.

Even though the efficiency of the 48V DC -> 120/240VAC inverters aren't that bad, they need electrolytic capacitors which really have a limited life span because of heat buildup. That is actually what kills most PV inverters.
I like the HV DC setup because you can derive the needed voltage fairly easy from it, without need step up units using those capacitors. I think that system will be more reliable than the 48V DC systems.

A PV inverter I replaced the electrolytic capacitors of:

 

[drmanny3]

I had understood that the batteries that would be used for home electrical storage would in fact come from cars when they were no longer viable. At least I had heard something similar to this. Car batteries would still have the capability to store and release energy perhaps not at the same rate necessary in a auto application. At one time I was imagining that the new battery factory would produce batteries generally for cars and yield various levels of performance. Like a semiconductor operation the yields can be sorted such that slower processors end up on lessor motherboards. Now that you mention a different chemistry that may change everything I thought was happening.

At one time I considered setting up a battery backup system. I decided against it for a couple of reasons. I really did not care about being off the grid and I thought the backup system was pricy. Now I realize that the battery backup system can be used in place of a solar panel system. You charge during the night and use the juice during the day when rates are significantly higher. I have heard payback times that are better than solar panels. There probably a lot of folks who either don't have the ideal southern exposure or just don't want panels on their roofs. The battery option could be a game changer.
Manny