Believe I am done with lead acid batts, going 120 full time with a Tesla Powerwall

[ElvistheKing]

Originally Posted by Hufficon

I think I'll just stay with my 12V like it is. Then I won't need to redo all the low-voltage wiring and replace all the bulbs in my coach. My gen-set produces 120v ac that does not have to be inverted (already 60 Hertz sine power). I like having the aux start for my chassis battery anyway.

Why would you need to change the wiring? If it's designed to handle 12v it'll handle 120v with ease.

[hohenwald48]

Originally Posted by ElvistheKing

Why would you need to change the wiring? If it's designed to handle 12v it'll handle 120v with ease.

Not according the the NEC it won't.

[Waiter21]

Sounds like an interesting project, Keep us posted.

[trx430ex]

Let me clear things up on the 12 volt side of the coach, that stays the same in every coach. Whether you plug into a campsite or you plug into the AC powerwall, the energy lights up the 12 DC volt converter in every coach. And powers the 12 volt DC side of the system, so nothing gets rewired or anything like that, so let's put that to bed.
https://electrek.co/2017/03/02/tesla...dc-version-ac/

Where I am working is on the AC side of the twin breaker panel, (120 volt panel) in order to ditch the coach lead acid bank. The 12 volt DC "existing"converter would be hooked up the powerwall full time (and probably on a switch) to power all the 12 devices just like the lead acid batteries do now. That isolates the 12 volt DC system to it's own existing universe.
So now we have the powerwall 15KW @120 volts AC powering the 120 volt AC side of a "30 amp" coach full time. While also supplying the 12 volt DC converter to cover the 12 volt DC devices full time. As you could see in Derek's video, when the system came online, he was running a well pump, washing machine, refrigerator & AC all at the same time. A tall task for any generator to put that much out at one moment, what this also proves is that energy storage can act like a buffer making you seem stronger than the system really is for short periods of time. And an impossible task for even a 6 bank Lead acid 600 pound system with an inverter to even attempt.
Bear with me as I know it can be a lot to wrap your head around.
If someone could convert RV lead acid spec to KW spec so we can compare apples to apples would be much appreciated. My twin 6 volt's are amp hr 232, 122 minutes @ 75 amps or 474 minutes @ 25 amps, (keep in mind this is still just 12 volts in the total of KW comparison.
Still working the 50 amp rigs, as they are 2 legs of 120 or 240 volt, which implies doubling of the power wall, but I do not know if 2 powerwalls would be 240 volt or just 2, 120 legs? I do not believe I have seen any double pole 220 breakers on a coach.

The main goal on this is not to be an energy pig, but to have all the 120 volt AC appliances work "full time", just like all the 12 volt devices work right now,, "full time". Want to make a pot of coffee without turning on the generator or plugging in, just do it.

[trx430ex]

Scarab0088, About a Honda 3000is VS Onan, 58 db VS 60 DB is a very confusing reference as DB is measured in a factor of ten. Trying to find an explanation in one sentence is equally challenging.To put it as simple as I can, @ a factor of ten for each DB, 60 DB would be 20 times louder than 58 DB. Honda really did some hard work getting those last 2 DB.

[Sbrownstein]

Bet you can't get rid of the starting batteries, perhaps even the house for the generator. Converters can't put out that kind of current without a battery for support.

[Scarab0088]

Originally Posted by trx430ex

Scarab0088, About a Honda 3000is VS Onan, 58 db VS 60 DB is a very confusing reference as DB is measured in a factor of ten. Trying to find an explanation in one sentence is equally challenging.To put it as simple as I can, @ a factor of ten for each DB, 60 DB would be 20 times louder than 58 DB. Honda really did some hard work getting those last 2 DB.

Not an acoustic expert, but I submit that each dB from a device is not an increase by a factor of ten...more like a factor of 10%:

https://en.m.wikipedia.org/wiki/Decibel

And...we have boondocked with folks using EU3000's and therefore can say with real-world experiences - Our Onan Marquis QG5500 produces a VERY SIMILAR sound level to 1 EU3000...but produces a much greater amount of power. That's just the perks of a built-in (not portable) unit where weight is a lesser concern. Two EU3000's would clearly produce much more noise.

Now...These details are really of no import because the Tesla Wall needs to be fed. If boondocking, that's a generator and/or solar, so noise will probably be part of this system.

If not intending to boondock, there is much less reason to bother. Just use the campground's power source.

If modifying your RV or building one specifically for this concept, I hope you share all about it here.
Best luck

[ElvistheKing]

Originally Posted by trx430ex

Let me clear things up on the 12 volt side of the coach, that stays the same in every coach. Whether you plug into a campsite or you plug into the AC powerwall, the energy lights up the 12 DC volt converter in every coach. And powers the 12 volt DC side of the system, so nothing gets rewired or anything like that, so let's put that to bed.
https://electrek.co/2017/03/02/tesla...dc-version-ac/

Where I am working is on the AC side of the twin breaker panel, (120 volt panel) in order to ditch the coach lead acid bank. The 12 volt DC "existing"converter would be hooked up the powerwall full time (and probably on a switch) to power all the 12 devices just like the lead acid batteries do now. That isolates the 12 volt DC system to it's own existing universe.
So now we have the powerwall 15KW @120 volts AC powering the 120 volt AC side of a "30 amp" coach full time. While also supplying the 12 volt DC converter to cover the 12 volt DC devices full time. As you could see in Derek's video, when the system came online, he was running a well pump, washing machine, refrigerator & AC all at the same time. A tall task for any generator to put that much out at one moment, what this also proves is that energy storage can act like a buffer making you seem stronger than the system really is for short periods of time. And an impossible task for even a 6 bank Lead acid 600 pound system with an inverter to even attempt.
Bear with me as I know it can be a lot to wrap your head around.
If someone could convert RV lead acid spec to KW spec so we can compare apples to apples would be much appreciated. My twin 6 volt's are amp hr 232, 122 minutes @ 75 amps or 474 minutes @ 25 amps, (keep in mind this is still just 12 volts in the total of KW comparison.
Still working the 50 amp rigs, as they are 2 legs of 120 or 240 volt, which implies doubling of the power wall, but I do not know if 2 powerwalls would be 240 volt or just 2, 120 legs? I do not believe I have seen any double pole 220 breakers on a coach.

The main goal on this is not to be an energy pig, but to have all the 120 volt AC appliances work "full time", just like all the 12 volt devices work right now,, "full time". Want to make a pot of coffee without turning on the generator or plugging in, just do it.

According to https://www.tesla.com/powerwall?redirect=no US spec powerwalls are rated at 5kW continouse, 7kW peak and 13.5kWh and weighs 125Kg.

5Kw @ 120v is 42amps.
7Kw @ 12v is 58amps.

I'm going to guess that your LA batteries are 30Kg each so for an accurate comparison weight for weight say you have 4, 2 parallel strings of 2 in series so 464Ah.

150amps @ 12 v is 1.8kW.

122minutes @ 1.8Kw is 3.66kWh

But the powerwall is using Lithium cells which are very light compared to LA, so lets instead compare with https://www.lithiumion-batteries.com...ries/sb260.php

These are 12v so no need to double them up, they weigh 27kg so for sake of argument we are again talking 4 batteries (but each battery is 12v so all in parallel so this 1040Ah).

They only have specs for a reserve rate of 50amps for 312minutes each so

200amps @ 12v is 2.5kW

312minutes @ 2.5Kw is 13kW

So it's not that it's some magic by Tesla as the same weight of Lithium leisure batteries gives approximately the same energy density. However the powerwall costs $6,000, 4x of those lithium batteries would for $12,000.

[nothermark]

Power budgets are always a cold bucket of water over the head. ;-)

One of the last places I would put a large weight is up high in the back of any vehicle. Lower down and nearer the rear axle is a lot better choice.

[Selah]

IF the power wall has a 12v out then it would be a good replacement for your house batteries. If it doesn't your looking ad a near complete rewire of the coach. All of the lighting would need to be retwired, the slide motors and hydrolics, exhaust fans, etc.
Changing out the Onan means losing your power management and AGS.
BTW: I have had my 10K Onan for four years (approx 500 hours) with zero problems.

[ElvistheKing]

Originally Posted by Selah

IF the power wall has a 12v out then it would be a good replacement for your house batteries. If it doesn't your looking ad a near complete rewire of the coach. All of the lighting would need to be retwired, the slide motors and hydrolics, exhaust fans, etc.

Changing out the Onan means losing your power management and AGS.

BTW: I have had my 10K Onan for four years (approx 500 hours) with zero problems.

Read the thread the OP specifically addressed that.

[slowmachine]

I don't see anything on Tesla's website about the Powerwall being designed to withstand the shock and vibration of vehicle travel. I also see no way to view the Powerwall warranty. I think it is a worthy idea, but I wouldn't be throwing $6000 into it without knowing that the device can survive the environment. A lithium battery fire will likely make you wish it were only the absorption refrigerator burning.

[ElvistheKing]

Originally Posted by slowmachine

I don't see anything on Tesla's website about the Powerwall being designed to withstand the shock and vibration of vehicle travel. I also see no way to view the Powerwall warranty. I think it is a worthy idea, but I wouldn't be throwing $6000 into it without knowing that the device can survive the environment. A lithium battery fire will likely make you wish it were only the absorption refrigerator burning.

Entering "powerwall warranty" into google will give you: https://www.tesla.com/sites/default/...nty_us_1-4.pdf

[aether_one]

Originally Posted by ElvistheKing

According to https://www.tesla.com/powerwall?redirect=no US spec powerwalls are rated at 5kW continouse, 7kW peak and 13.5kWh and weighs 125Kg.

5Kw @ 120v is 42amps.
7Kw @ 12v is 58amps.

I'm going to guess that your LA batteries are 30Kg each so for an accurate comparison weight for weight say you have 4, 2 parallel strings of 2 in series so 464Ah.

150amps @ 12 v is 1.8kW.

122minutes @ 1.8Kw is 3.66kWh

But the powerwall is using Lithium cells which are very light compared to LA, so lets instead compare with https://www.lithiumion-batteries.com...ries/sb260.php

These are 12v so no need to double them up, they weigh 27kg so for sake of argument we are again talking 4 batteries (but each battery is 12v so all in parallel so this 1040Ah).

They only have specs for a reserve rate of 50amps for 312minutes each so

200amps @ 12v is 2.5kW

312minutes @ 2.5Kw is 13kW

So it's not that it's some magic by Tesla as the same weight of Lithium leisure batteries gives approximately the same energy density. However the powerwall costs $6,000, 4x of those lithium batteries would for $12,000.

I don't know if you were mistyping or miscalculating, but your math makes no sense.

Ignoring power factor, a 1 watt is 1 amp at 1 volt regardless of AC or DC.

So:
"5Kw @ 120v is 42amps.
7Kw @ 12v is 58amps."

is really 120 x 42 = 5040 Watts (5 KW)
but 12 x 58 = 696 (.7 KW)
This is the Power being used.

There are other issues where I think you substituted the wrong unit in your equations or your units make no sense.

For example:
"312minutes @ 2.5Kw is 13kW"
When you include time in the equation you end up with Energy, so Power x time = Energy or KW-Hour (not kW).