Hey Lee, Rob,
Ahh if the hack is something you can do safely, then let's do it. But
want to mention some other things to consider:
- Lee, yes, using that half portion of a 12-120Vac inverter is a great
idea, I've done that before and is especially efficient (high frequency V
step-up electronics). But in the case of a 12-120V inverter, those will
only get to a max of 300V (in fact, it is a little bit less. Usually the
Caps are 300V Max. rated) and in the case of the Volt (almost any actual EV
in the market) are made of 96 cells in series, which have a voltage span
from 310V to 403V..ish from 0 to 100% SOC. (Volt x cell goes from 3.25V to
4.2V approx.) so that inverter wouldn't be able to provide enough high
voltage to 'transfer' the energy from the solar panel. a 12-240Vac inverter
would be needed instead.
- Then, how would you control the current on the HV side? those inverters
usually dump as much power as possible and it is up to the HV H-Bridge (the
one in charge of creating the AC since wave), the one that measures current
to prevent the damage of their electronics. In this case, if you
successfully make the voltage go higher how that would be controlled?
Also, since the 12-120V inverter does not have MPPT like all solar charge
controllers, if the sun is not powerful enough (at dusk and at down or in
partial shadow) the inverter will try to get more power out the solar, but
the solar panel won't be able to meet that request and then the inverter
will halt and that may damage it or create weird behavior.
- Third; if you dump that power directly into the HV battery, the on-board
BMS won't be able to sense/track that (since it will be on sleep mode) and
after some hrs of energy transfer accumulated, you will 'Off-set' the BMS
parameters and pretty sure the gauges on your dashboard will become
inaccurate and maybe set some trouble codes as well. The other concern is,
what if you are almost fully charged and you start 'overcharging' cells
with no BMS supervision/management? I don't think it would be a good idea.
- Finally, adding that HV circuitry, may also impact the internal HV
isolation for the complete wiring system. Again, with the possibility to
set trouble codes on the BMS and worst case scenario; prevent it from
closing HV contactors when about to drive.
...my 2 cents
Marco Gaxiola
On Mon, Feb 17, 2020 at 10:38 AM Gail Lucas via EV <ev@lists.evdl.org>
wrote:
> Bob,
>
> So nice to have you back. It will be interesting to see your new project
> when you are putting it together. I hope you recover quickly so you can
> resume your activities.
>
> Gail
>
>
> On 2/16/2020 1:10 PM, Robert Bruninga via EV wrote:
> > When I recover in a few months, you can see my ideas for flattening the
> roof
> > and adding 240W of solar panels to my Volt in a Back-to-the-future
> design
> > on this web page. Also adding a bed for a Volt-Inn.
> >
> > I know it makes no practical economic sense, but makes it a real
> eye-catcher
> > and conversation starter.
> >
> > Now all I have to figure out is where I can feed in the 300 VDC for
> charging
> > the HV battery...
> >
> > http://aprs.org/my-EVs.html
> >
> > Bob
> > _______________________________________________
> > UNSUBSCRIBE: http://www.evdl.org/help/index.html#usub
> > ARCHIVE: http://www.evdl.org/archive/index.html
> > INFO: http://lists.evdl.org/listinfo.cgi/ev-evdl.org
> > Please discuss EV drag racing at NEDRA (
> http://groups.yahoo.com/group/NEDRA)
> >
> >
> _______________________________________________
> UNSUBSCRIBE: http://www.evdl.org/help/index.html#usub
> ARCHIVE: http://www.evdl.org/archive/index.html
> INFO: http://lists.evdl.org/listinfo.cgi/ev-evdl.org
> Please discuss EV drag racing at NEDRA (
> http://groups.yahoo.com/group/NEDRA)
>
>
-------------- next part --------------
An HTML attachment was scrubbed...
URL:
<http://lists.evdl.org/private.cgi/ev-evdl.org/attachments/20200217/b2c6a7b0/attachment.html>
_______________________________________________
UNSUBSCRIBE: http://www.evdl.org/help/index.html#usub
ARCHIVE: http://www.evdl.org/archive/index.html
INFO: http://lists.evdl.org/listinfo.cgi/ev-evdl.org
Please discuss EV drag racing at NEDRA (http://groups.yahoo.com/group/NEDRA)
