zanary
Active Member
If you are on Whole Home Backup (without solar), then your powerwall chargers at 3.x kW. I have two Powerwall's, they the app shows them charging at 3.x kW. II think when you have solar, it charges far more quickly.
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Powerwall 2: Technical
- Thread starter Aussie
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- Powerwall Tesla Energy
If you are on Whole Home Backup (without solar), then your powerwall chargers at 3.x kW. I have two Powerwall's, they the app shows them charging at 3.x kW. II think when you have solar, it charges far more quickly.
Ulmo
Active Member
Ulmo
Active Member
Ulmo
Active Member
I would think any electrician or HVAC service person could install one. (It goes inside your outside A/C unit.)
Ulmo
Active Member
I have a feeling there will suddenly be a lot of people specifying low start power compressors from now on.
There are probably lots of ways to do that.
The first thought I had was rather a kludge -- a flywheel used just during compressor start, with a dedicated starter motor to ramp up the flywheel. The compressor wouldn't try its start until the flywheel was up to speed and starter motor turned off. The mechanics alone would be daunting. This would require a new compressor design.
Similarly, a flywheel system could be used with a dual-use motor generator (obviously sized for the particular task) that first got the flywheel up to speed (as motor), disconnected the whole unit from line, started generating electricity from the flywheel (as generator), started the compressor from the generated electricity connected to the still spinning flywheel (obviously sized for the particular task), then when the flywheel generator voltage crossed 0 at the same time as line, switch instantly over to line. The flywheel motor could have a very low start current and could draw less power from line to spin up the flywheel than the compressor during running operation; why not? It's not in any hurry to get the flywheel up to speed. Where that motor needs a lot of power is in generation from the flywheel to the compressor. This kind of device could be attached to any compressor in serial in between it and the power source.
Ulmo
Active Member
Apparently, this is what happened. We've had confirmation from other people that GBUKENAS is indeed backward, and has no backup. Maximum government power, minimum citizen power.
Parzival
Member
Yes, but I'm told the soft start unit is about $400 so I am happy to let Tesla pay for it.
zanary
Active Member
The app only shows them as a single unit even though there are two so that’s where it also shows 3.3kw.
I’m guessing each one is 3.3kw because of the singular view regardless of how many are connected together.
eml2
Member
Yesterday I called Tesla support. They confirmed that my PW was indeed changed from 1.7.0 to 1.6.0. They said they would look into it. Then, around 9:30 pm, I noticed my PW stopped supplying power to my house for about 15 mins. When I checked again, it was back to 1.7.0.
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zanary
Active Member
Did they tel you if 1.7.0 is only for Solar customers, or will Whole Home Backup customers also get 1.7.0? I'm still on 1.6.0 right now.
eml2
Member
They didn't mention anything about solar nor did I. The only thing they asked me to confirm is that I have 2 PW's
Ulmo
Active Member
I'm guessing it is limited to 3.3kW for the total, so 1.65kW each. I find it interesting that they consider that the safe charge speed when a choice is given. However, that might be more about keeping wires cool, demand charges low, and neighborhood transformers cool.
Ulmo
Active Member
That means at least a max of 3.2kW charging for each PowerWall 2 when connected to solar.
zanary
Active Member
What’s interesting is that each Powerwall is connected to a 30/220 amp breaker.
So each Powerwall is (24x220) = 5.2kw. Max.
My thinking is that each charges at 3.3kw.
Shygar
Member
My single PW2 shows charging at 1.7kWh max from solar. Tesla guy who installed said they are limited at that charging rate. Maybe 1.65kWh is the correct amount, just rounded up for the app.
zanary
Active Member
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One of the problems with Tesla is they don't document products that well, or at least for the general public. You almost have to reverse engineer how this stuff actually works.
What I would like to do is have a set of powerwall 2's as part of a backup system with a diesel generator. I don't think I can generate enough solar reliably to power the whole house, but the problem with generators is they are only really efficient at about 20% of rated power up. Under that they waste fuel and you get build up in the engine that causes additional maintenance.
What I would love to do is have 2-3 Powerwall 2's that would be charged by Solar, and power the house normally in an outage, but if the powerwall gets almost drained to start a generator, and have the generator take the house load but also charge the powerwalls at a decent rate. This would allow the generator to stay off at low loads but kick in when needed, and operate at a high enough output to be efficient. I don't want the genset running at night with barely any load, but for peak use, you need that when some of the appliances or HVAC is running full tilt.
None of the electrical contractors or solar companies I have talked to know near enough to figure out how to get a powerwall to play this game. They can do it with hybrid inverters and DC battery sets from LG or lead acid batteries etc...., but all those are expensive and not something you want in your garage.
What I would like to do is have a set of powerwall 2's as part of a backup system with a diesel generator. I don't think I can generate enough solar reliably to power the whole house, but the problem with generators is they are only really efficient at about 20% of rated power up. Under that they waste fuel and you get build up in the engine that causes additional maintenance.
What I would love to do is have 2-3 Powerwall 2's that would be charged by Solar, and power the house normally in an outage, but if the powerwall gets almost drained to start a generator, and have the generator take the house load but also charge the powerwalls at a decent rate. This would allow the generator to stay off at low loads but kick in when needed, and operate at a high enough output to be efficient. I don't want the genset running at night with barely any load, but for peak use, you need that when some of the appliances or HVAC is running full tilt.
None of the electrical contractors or solar companies I have talked to know near enough to figure out how to get a powerwall to play this game. They can do it with hybrid inverters and DC battery sets from LG or lead acid batteries etc...., but all those are expensive and not something you want in your garage.
The PowerWall is inherently not good at working with a generator. What you really need is a separate AC input to the system for the generator that is free running and not synchronized to the battery inverter output. This is what Hybrid inverters do - they basically have a separate battery charger running off the generator input. I believe someone said that Tesla is doing a trial with a handful of customers that have generators to see if their preliminary solution works as expected. I assume they are nesting the Tesla gateway inside the generator's transfer switch so that the Powerwall can synchronize to either the grid or the generator. The only question is how they are controlling when the generator starts. Most would automatically start after a few seconds of grid outage. You wouldn't want that to happen with a PowerWall.
