Things that make you go "Hmmmm?" about batteries.Tesla Motors (TSLA) is set to announce a new product today...but it's not a car. Speculation is CEO Elon Musk will unveil batteries for homes and businesses that are more advanced than what's currently on the market.

SCVJeff wrote:In a GC-2 package...That's a lot of lithium... and in a small package too, for the amount of A/H.Musk snake oil?

Hi Niner,I'd be very interested in a used leaf or other electric car battery. There would be plenty of "juice" left for running an RV.

I could easily see this as an option in a higher end Class A.Adding an interface to charge with solar can't be that hard.

Power wall--10 Kwh for $3500. That is actually a practical price and features for some. Shipping will start in two-three months. I see that the nominal current is only 5 A and peak, 8.5 A for a single module. That almost assures that anyone using these will need multiples.

Batteries | Good Sam Community

60 Replies

jrnymn7
Explorer
May 10, 2015
grizzzman wrote:
jrnymn7 wrote:
Those Progressive Dynamics Li Chargers just don't sit well with me. It seems every article I've read regarding charging LiFePo4 mentions lower voltages, like in the mid to upper 13's. And that makes me wonder if a basic single voltage ~13.6v charger would be better suited to Li?

They are banking on the BMS to deal with it. I see nothing but bad juju at that voltage.

Yeah, it's one thing to smoke an $89 sam's club battery, but at $12/Ah for LiFePo4, I'd steer way clear of PD's approach to charging Li.
MEXICOWANDERER
Explorer
May 09, 2015
Sounds like they have a washboard-grade number of wrinkles to flatten before this hookah-grade fantasy advances to pipe dream status...

Combine brand new technology with a gigantic database and there are going to be legions of gremlims to overcome. This is guaranteed.
pianotuna
Nomad III
May 09, 2015
Hi,

The inverter needed for the Powerwall is $2k. That's way out of my league.
westend
Explorer
May 07, 2015
The other missing piece of the Powerwall puzzle is the inversion. The Powerwall unit does not come with an inverter. Like Pianotuna mentioned, there is silence on this and it is an expensive piece to add. It may be that there is connection interface back into an installed solar controller but nobody is talking about the details.
grizzzman
Explorer
May 07, 2015
jrnymn7 wrote:
Those Progressive Dynamics Li Chargers just don't sit well with me. It seems every article I've read regarding charging LiFePo4 mentions lower voltages, like in the mid to upper 13's. And that makes me wonder if a basic single voltage ~13.6v charger would be better suited to Li?

They are banking on the BMS to deal with it. I see nothing but bad juju at that voltage.
jrnymn7
Explorer
May 07, 2015
Those Progressive Dynamics Li Chargers just don't sit well with me. It seems every article I've read regarding charging LiFePo4 mentions lower voltages, like in the mid to upper 13's. And that makes me wonder if a basic single voltage ~13.6v charger would be better suited to Li?
pnichols
Explorer II
May 06, 2015
MrWizard wrote:
Oh..Yeah..!!
200+ diodes in a series string, just like old Xmas tree lights

NOT...for me

But ... but ... but ... aren't diodes ultra-cheap and ultra-reliable? Remember the goal at all times is to K.I.S.S. :B

P.S. It would take a lot more diodes in a series string than 200.
SCVJeff
Explorer
May 06, 2015
pianotuna wrote:
Hi 2oldman,

Naw, just bring the 400 DC to 120 volts AC and power a standard 13.6 volt converter.
Probably find a spare from a B-52...
MrWizard
Moderator
May 06, 2015
Oh..Yeah..!!
200+ diodes in a series string, just like old Xmas tree lights

NOT...for me
pnichols
Explorer II
May 05, 2015
Well ... how about this non-rocket science approach: Since silicon diodes drop their input DC voltage by 0.7 volts with very little heating loss, use X number of heavy-enough-current-rated silicon diodes in series to drop 400 DC volts down to whatever DC volts you need to economically invert these DC volts to 120 volts AC. Wala!!