Okay, but an inverter generator is pretty low maintenance, relatively speaking. They only hold a gallon, and you run it until it's empty, so there's no fuel in the tank to go bad. When there's a power outage, you get your fresh gas before the lines form. 10 gals of gas in an inverter generator can run just your fridge for 5 days easy.The 3000W inverter I have is technically supposed to do 250A at peak use. It came with thick (and short-ish) cables. I agree that getting 100A or more on any distance requires thick cables. To be honest, I'll cross that bridge when I get to it (thicker cables), for now I'd be happy with even 20-30A which is trivial to do on the cables I currently have.
Not a bad question. Gas generators require non trivial maintenance and if you use them once every other year, even with fuel stabilizer, the fuel will be no good.
Otherwise, it's also because I'm an engineer, and why not?
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How many amps can you get from the 12V system for emergency situations?
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There are pros and cons, I've given some, there are more. I have looked into that option and I'm not interested.
I have 70Kwh or so in my car when it's full, I'm interested in using that instead if need be.
I do like the idea conceptually. I just think the risk/difficulty factor climbs pretty quickly trying to go from several hundred Watts to 3000W.
Agreed. Honestly I don't need 3000W, I just oversized the inverter to make sure it doesn't die and can handle power on spikes as discussed earlier in the thread.
In the meantime, I found where to get a proper 12V connection including the warning about using a pre-charging resistor to handle the current inrush (and my inverter does cause a big spark every time I connect it and its massive capacitors, charge up)
Tesla Model 3 Stereo - Part 9: Summary and Lessons Learned
Related reading:
Aftermarket Sub-woofer Amplifier Installation using DC-DC +12v Power Source
and I'm going to get this relay to delay the current inrush in the inverter:
https://www.amazon.com/ONLINE-LED-STORE-Charge-Switch/dp/B01MYPTVJD?th=1
in parallel with a big resistor like
https://www.amazon.com/Cutequeen-Aluminum-Wirewound-Chassis-Resistor/dp/B01LXBG5LN
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ambudriver03
Member
Agreed. Honestly I don't need 3000W, I just oversized the inverter to make sure it doesn't die and can handle power on spikes as discussed earlier in the thread.
In the meantime, I found where to get a proper 12V connection including the warning about using a pre-charging resistor to handle the current inrush (and my inverter does cause a big spark every time I connect it and its massive capacitors, charge up)
Tesla Model 3 Stereo - Part 9: Summary and Lessons Learned
Related reading:
Aftermarket Sub-woofer Amplifier Installation using DC-DC +12v Power Source
and I'm going to get this relay to delay the current inrush in the inverter:
https://www.amazon.com/ONLINE-LED-STORE-Charge-Switch/dp/B01MYPTVJD?th=1
in parallel with a big resistor like
https://www.amazon.com/Cutequeen-Aluminum-Wirewound-Chassis-Resistor/dp/B01LXBG5LN
Is there a way to fashion a pigtail with an Anderson 350 connector on there with some 2/0 battery cable?
android04
Active Member
Disconnecting the black rectangular plug right above the red bounding box in the picture is what Mountainpass Performance states will do a full reset of all systems in the car Tesla Model 3 Hard Reset
We were also effected by these latest PSPS. We are going full on Solar + Powerwall. I prefer to do this rather than risk damaging the battery in the cars. Also, the solar plus powerwall should allow us to greatly reduce the monthly electric costs. It should let us send energy back to the grid during the day and power the house during peak rate times in the evening.
FlatSix911
Porsche 918 Hybrid
See my signature below... Model S dual motor with charging posts located directly behind the nose cone.
android04
Active Member
Not sure what a "CAC reset" is, but this method cuts power to everything in the car. Not even just disconnecting the 12v battery does that because the DC-DC converter can still keep other things powered up.
I'm not going to fork this thread on powerwalls since I specifically said I was not interested in them, and knew why I was not, but in a nutshell, at least in California, PG&E does not allow you to do time of use shifting during a powerwall and storing solar into a powerwall to use it at night, actually makes you lose money vs not having a powerwall and feeding that solar back in the grid during the way. Read up, powerwalls make a lot less sense than people think they do. Kudos to Tesla marketing for making them think otherwise.
That's what I thoughtSee my signature below... Model S dual motor with charging posts located directly behind the nose cone.
I was asking about model 3, so knowing where it is on model S wasn't that useful Marc
FlatSix911
Porsche 918 Hybrid
Agreed. Honestly, I don't need 3000W, I just oversized the inverter to make sure it doesn't die and can handle power on spikes as discussed earlier in the thread.
In the meantime, I found where to get a proper 12V connection including the warning about using a pre-charging resistor to handle the current inrush (and my inverter does cause a big spark every time I connect it and its massive capacitors, charge up)
Tesla Model 3 Stereo - Part 9: Summary and Lessons Learned
Related reading:
Aftermarket Sub-woofer Amplifier Installation using DC-DC +12v Power Source
and I'm going to get this relay to delay the current inrush in the inverter:
https://www.amazon.com/ONLINE-LED-STORE-Charge-Switch/dp/B01MYPTVJD?th=1
in parallel with a big resistor like
https://www.amazon.com/Cutequeen-Aluminum-Wirewound-Chassis-Resistor/dp/B01LXBG5LN
Did you complete your inverter installation... inquiring minds want to know
So I'm going to start right of saying that I do not know the setup for Model 3. But you said you have read the threads that I personally have posted in regarding Model S.
I believe your problem lies in that you are draining off the larger buffer battery with your house inverter. It is best to have the batteries sized the same if you are going to parallel batteries. You need the bigger battery as the first battery off the HV car 12 volt battery charger and your buffer (if used) should be the same size. If you are determined to use the smaller battery it needs to be the one that is at the end next to your house inverter but is still not ideal and I don't recommend it.
Using the smaller battery as the pass through (as you are doing) will not force the onboard car charger to see the larger low charged volume battery at the end that your home inverter is sucking from. The larger volume battery at your inverter end will only slowly equalize from the smaller volume battery.
Doing it with small battery sandwiched between the HV and buffer battery will have a slinky like effect. Just add a larger battery (preferably lithium) to your car and the onboard car charger should keep up. If you feel it won't because of your possible load then add a buffer battery of the same size and type. You will not get the slinky effect if you hook your positive cable to opposite end of your paralleled (banked) (same sized) batteries from your negative cable.
I run mine without a second battery. My 12 volt is lithium and it runs a 2000 watt.
Good luck and tell us how it goes.
I believe your problem lies in that you are draining off the larger buffer battery with your house inverter. It is best to have the batteries sized the same if you are going to parallel batteries. You need the bigger battery as the first battery off the HV car 12 volt battery charger and your buffer (if used) should be the same size. If you are determined to use the smaller battery it needs to be the one that is at the end next to your house inverter but is still not ideal and I don't recommend it.
Using the smaller battery as the pass through (as you are doing) will not force the onboard car charger to see the larger low charged volume battery at the end that your home inverter is sucking from. The larger volume battery at your inverter end will only slowly equalize from the smaller volume battery.
Doing it with small battery sandwiched between the HV and buffer battery will have a slinky like effect. Just add a larger battery (preferably lithium) to your car and the onboard car charger should keep up. If you feel it won't because of your possible load then add a buffer battery of the same size and type. You will not get the slinky effect if you hook your positive cable to opposite end of your paralleled (banked) (same sized) batteries from your negative cable.
I run mine without a second battery. My 12 volt is lithium and it runs a 2000 watt.
Good luck and tell us how it goes.
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jonquiljo
Active Member
Sorry to get a bit off topic, but do you know where I can get information regarding this? My wife and I have vowed we will NOT ever go through that PG&E nonsense ever again. I've talked to some people at Tesla and, like the people selling cars, they are very young, inexperienced, and far from engineers. To top that, I was told that Tesla will not install on tile roofs anyway - which is what we have.
So our alternatives are a 60Kw generator with all the permits, noise, etc. to handle the whole house - or solar with Powerwalls. I'd need at least 4 powerwalls to handle the needs of this house. As most of us remember, the lack of heating/cooling after a while became worse than living with flashlights. Inexperienced people are OK to sell us Tesla cars, as most of us can figure out what we want to do. But you don't throw $80K worth of equipment on a house worth at least 20 times that, and feel comfortable doing so. Where do you find competent info?
Kind of, read onDid you complete your inverter installation... inquiring minds want to know
Ok, so I hear and understand everything you're saying but it seems that model3 is clearly limiting the charge going to the buffer 12V battery. From what you're saying, I should just be able to drain 10A from it with a small inverter, and it should get topped off quickly enough, but it seems that on model3, the charging speed is limited, and it recharges more slowly as it discharges.
As for "The larger volume battery at your inverter end will only slowly equalize from the smaller volume battery". That is not correct. If the cable between them is thick enough, amps will flow from both batteries as regulated by their internal resistance, and any imbalance between them will quickly resolve itself as long as the wire between them is thick. I know that because I have another system with a big and small battery and as long as I equalize them before connecting them the first time, they stay at the same voltage forever after that regardless of what I draw from them.
Back to what I had to do: I thought it would be as simple as plugging the big inverter directly into the 12V connection from the DC-DC converter, but I found the following:
1) unscrewing the bolt to the 12V + connection point gets it to disconnect just enough that the car can sense amps aren't flowing as well and can get upset with error messages. It's better to find a right size bolt, and add the second connector on top without disturbing the first one.
2) the converter is sensitive to high amps. Inverters have a huge capacitor and draw enough amps when you connect them to make a big ass spark. When that happens, enough amps are drawn that the DC-DC inverter shuts off. When it does, it shows 1.3V and does not turn back on easily, or at all.
Once you're in that state, this is bad because your buffer 12V battery does not get recharged and starts draining until it's empty. Once, it reset itself on its own, and another time, it did not and I had to feed 12V to the external battery so it didn't go flat
3) I haven't figured all the ways the DC-DC converter can turn itself back on, but eventually found that if you disconnect the + from the buffer battery while the DC-DC converter is shut down, then the entire car has no power, and shuts off for good. Once you connect the battery back, the DC-DC converter turns back on and everything comes back to normal
4) well, almost, if your 12V battery is too low, the car tells you it needs to be replaced and somehow fails to charge it to a suitable level, even after 24H. I had to unplug it, use an external charger to bring it back to 13.5V, and now everything is back to normal. This further confirms that the model3 battery charger is weak and/or limited
5) I now have a careful method to power on my inverter using a resistor to limit current when it equalizes and then connect the full bypass cable once that's done. This is error prone though and may need to be repeated each time the inverter shuts off after the DC-DC inverter turns off for whatever reason. However, once it's up and running, it ran my fridge for hours without issues.
I haven't solved the current inrush problem yet, but I'm thinking about using a zener diode across the inverter connections that will control a bypass relay that allows a full connection to the inverter, bypassing the current limiting resistor. The diode will only allow current flow to the relay once enough equalizing has been done through the resistor.
That will take a bit of time to build, but I'm reasonably certain it will work.
I don't have time right this minute to address everything you have said, yet. The longer bolt on my battery is how my hot to inverter is connected. I have mine permanently installed in the car so not an inrush situation here but you could have a contactor with an on/off switch or just a straight out on/of battery switch without contactor might work as well as the solution you mentioned for arching.
If you hook up your bank as you are doing, your onboard charger will not keep up with the buffer battery at the end especially if it is the bigger battery and you have both of your inverter leads connected only to that battery and not to each opposite end of the two paralleled batteries.
Look online to see the optimum way to attach an inverter and a charger to a paralleled battery bank. Also, no one will go along with you on paralleling mismatched battery capacities because it is not good in the long run.
The onboard car charger will always see the first battery the way that you have it unless you hook the negative directly from your car to your paralleled buffer battery and the positive from you car charger to what you are saying is your smaller car battery that is paralleled to your larger buffer battery.
Bottom line is you need to change out that smaller battery to start with even if you don't follow the other best methods.
If you hook up your bank as you are doing, your onboard charger will not keep up with the buffer battery at the end especially if it is the bigger battery and you have both of your inverter leads connected only to that battery and not to each opposite end of the two paralleled batteries.
Look online to see the optimum way to attach an inverter and a charger to a paralleled battery bank. Also, no one will go along with you on paralleling mismatched battery capacities because it is not good in the long run.
The onboard car charger will always see the first battery the way that you have it unless you hook the negative directly from your car to your paralleled buffer battery and the positive from you car charger to what you are saying is your smaller car battery that is paralleled to your larger buffer battery.
Bottom line is you need to change out that smaller battery to start with even if you don't follow the other best methods.
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Sorry, I still don't get it. Why power your house with your Tesla. It wasn't designed for that. Gas generator hooked into your house thru a transfer switch powers everything you choose. That includes your refrigerator, HVAC, TV & computers, you name it. Power goes out and you still live in style. My neighbor has his Generac hooked into his natural gas supply. System works automatically even if they aren't home. Gas generator maintenance is simple. Change the oil each year. Use a fluid transfer pump to replace the gas every 6 months. If you no longer have an ICE, your neighbors will be happy to have the free fuel.
It seems to me it would be trivial to build a current-limiting circuit, rather than depending on some random mystery wire/bolt resistance. I've never had to build one that handled 10+ amps, but I'd bet the parts would cost almost nothing. This would avoid inrush issues, overload issues, and so on...
You are talking about a Model S, not a Model 3, correct?
As stated earlier, I tried an 85W load with a cheap small inverter, and is was just around 7A. Even with that, the battery was discharging faster than it was recharging, even when I removed the buffer battery that you say is the cause of all this (and I don't quite agree with you on, but I removed it to make it quicker to measure whether the entire system was charging or discharging with such a small load).
As for the inrush, the problem is my 3000W inverter has a huge capacitor. If it is allowed to drain (because it's unpowered for a while), the moment power comes back, it will try to recharge instantly, likely drawing over 200W, in turn causing the DC-DC converter to trip due to a perceived short.
The solution I explained above, but haven't implemented yet, should take care of that.
Natural gas generators are great, such a solution is however expensive and totally overkill for a once every few years use, at most. If I lived in a place with much more unreliable power, I would consider that approach.
Agreed, the system I described above is not a mystery. It uses a 100W resistor to limit current during the inrush, and then a relay to bypass the resistor once the inverter voltage is equalized to 12V and inrush is not a problem anymore.
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