T-Pain Is On A Boat: Re: [Electric Boats] Re: Powerwall from Tesla, residential battery pack at $0.35/wh

Thursday, May 7, 2015

Re: [Electric Boats] Re: Powerwall from Tesla, residential battery pack at $0.35/wh

Whether you go AC or DC, you will still require some sort of converter between the battery bank and the controller input. The PowerWall outputs 350-450VDC. It doesn't include the DC/AC inverter since you have the choice of 120, 240, single phase, 3-phase, etc. Or, you could get a DC/DC converter to step the battery voltage down to whatever your controller wants. But since most DC/DC converters are just DC/AC/DC transformers, might as well just go straight to AC output in whatever form you like.
So I guess, yeah, it probably makes more sense to look at industrial AC drive systems.

/Jason

On May 5, 2015, at 08:25, Peter Gravel peterrgravel@gmail.com [electricboats] <electricboats@yahoogroups.com> wrote:

Thanks For that Hannu.

For the many (I assume) fence sitters out there this is the kind of news to make that final decision much easier.
It makes good business sense for Tesla to open up their systems to business and industrial use, hence more and more systems will be developed. Why else build this large battery complex?

I'm wondering if, considering the Powerwall, it's more advantageous to look at AC motor systems over DC?

This has definitely convinced me to go electric (great news as my 35 year old Yanmar is getting way too old).

Peter

On May 4, 2015, at 11:28 PM, Hannu Venermo gcode.fi@gmail.com [electricboats] <electricboats@yahoogroups.com> wrote:
Those batteries can deliver about 30% of the max load over 5000 cycles (vs 7000 cycles for Tesla).
So, your equivalent energy vs lion is == 30% x 2.5 kWh = 0.750 kWh.
Cost:

This is actually about 10 / 0.750 = 13.13
13.3 x 350 = 4666$ for a usable 10 kWh.
So, about a bit more (==20%) than the lion from Tesla (guaranteed to work 7 years *in daily use*).
In *daily use* no std traction battery will last more than 3-6 years at best.

Or, you can get about 50% DOD out of them for about 2-3000 cycles.
== 1.25 kWh.

Lion is actually about the same cost as other battery tech, when actual power delivered is compared.
At about 1/4 the mass and space.

On 03/05/2015 02:01, billhopen@yahoo.com [electricboats] wrote:

they are heavier, 4 batteries weigh 100lbs, that's roughly 2-3 x heavier per Kwh as tesla....but who cares in a boat?,,you are not going up hills, don't need a suspension and boats need balast anyway.

the big difference is price, my 4 batteries cost $350. total (delivered cost) while my batteries are 1/4 the power...its 1/10 the cost, that is 2.5x cheaper, and fifty volts is just perfect (and safer in a salt water environment) I don't want no 450 volts when a salt water wave comes in my cockpit, and I'm standing knee deep in short circuit. I don't need an expert electrician to install them, and I just need a $15 Chinese 3000watt PWM controller to run 50v direct to my motor
--   -hanermo (cnc designs)  