# Re: [EVDL] question about DC 2 CD converter



## EVDL List (Jul 27, 2007)

*Re: [EVDL] question about DC 2 CD converter*



> BBrown wrote:
> > I am converting my 1999 S10 pickup, 144vdc, 24 6vdc US125 batteries, Curtis
> > controller, Advanced 4001a motor.
> >
> ...


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## EVDL List (Jul 27, 2007)

*Re: [EVDL] question about DC 2 CD converter*



> Lee Hart wrote:
> > The Iotas are ordinary AC-input, fixed voltage DC-output power supplies;
> > they are not battery chargers or DC/DC converters. People just *use*
> > them as DC/DC converters because they are cheap and it works (sort of).
> ...


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## EVDL List (Jul 27, 2007)

*Re: [EVDL] question about DC 2 CD converter*

They are missing the durability and ruggedness to survive well in an
under-hood environment. They don't deal well with vibration, moisture,
or dirt.

-Morgan LaMoore

On Sun, Jul 27, 2008 at 11:05 AM, John G. Lussmyer


> <[email protected]> wrote:
> > Lee Hart wrote:
> >> The Iotas are ordinary AC-input, fixed voltage DC-output power supplies;
> >> they are not battery chargers or DC/DC converters. People just *use*
> ...


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## EVDL List (Jul 27, 2007)

*Re: [EVDL] question about DC 2 CD converter*



> John G. Lussmyer wrote:
> > Okay Lee, please define "(sort of)". Specifically, what part of DC-DC
> > converter functionality are they missing?
> 
> ...


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## EVDL List (Jul 27, 2007)

*Re: [EVDL] question about DC 2 CD converter*



> Lee Hart wrote:
> > For EV use:
> >
> > - no input fuse
> ...


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## EVDL List (Jul 27, 2007)

*Re: [EVDL] question about DC 2 CD converter*

Don't know how much good it will do, but after reading this thread about 
the vinration problems with these power supplies, I have purchased a 
set of rubber vibration dampener mounting studs - rubber mount with 
1/2"x20 threaded stud on each end.
It might not be the end all of all endalls, but it sure won't hurt.
We'll see how it stands up to the test of time - I'll let y'all know in 
a year or two.

I've also printed out the list of suggested mods my Lee Hart, and they 
should help it's longevity.
It */was/* the most economical (read: cheapest) DC Converter offered for 
sale. At this point I have spent my money, and I'm just hoping that if I 
take care of it, it might last for at least a little while.
Besides, one of the beauties of this endeavor is: "I built it - I can 
fix it."
Bob







> John G. Lussmyer wrote:
> > Lee Hart wrote:
> >
> >> For EV use:
> ...


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## EVDL List (Jul 27, 2007)

*Re: [EVDL] question about DC 2 CD converter*

>> 1. no input fuse
>> 2. no inrush current limiter
>> 3. no overvoltage protection
>> 4. poor output fuse protection
>> 5. no algorithm or temperature compensation for battery charging
>> 6. not packaged for automotive use



> John G. Lussmyer wrote:
> > Looks like #1,2,4 can be relatively easily "fixed".
> 
> Correct! Once you are aware of the problems, these parts can be easily
> ...


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## EVDL List (Jul 27, 2007)

*Re: [EVDL] question about DC 2 CD converter*

Why would you hook up an Iota such that it was exposed to charging voltage?



> Lee Hart <[email protected]> wrote:
> >>> 1. no input fuse
> >>> 2. no inrush current limiter
> >>> 3. no overvoltage protection
> ...


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## EVDL List (Jul 27, 2007)

*Re: [EVDL] question about DC 2 CD converter*



> storm connors wrote:
> > Why would you hook up an Iota such that it was exposed to charging voltage?
> >
> 
> ...


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## EVDL List (Jul 27, 2007)

*Re: [EVDL] question about DC 2 CD converter*

>


> > storm connors wrote:
> >> Why would you hook up an Iota such that it was exposed to charging
> >> voltage?
> >>
> ...


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## EVDL List (Jul 27, 2007)

*Re: [EVDL] question about DC 2 CD converter*

On Sun, 27 Jul 2008 18:11:45 -0400, "storm connors" <[email protected]>


> wrote:
> 
> >Why would you hook up an Iota such that it was exposed to charging voltage?
> 
> ...


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## EVDL List (Jul 27, 2007)

*Re: [EVDL] question about DC 2 CD converter*



> Lee Hart <[email protected]> wrote:
> 
> 
> >> #3 - If you run your pack over the voltage rating of the unit, it dies.
> ...


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## EVDL List (Jul 27, 2007)

*Re: [EVDL] question about DC 2 CD converter*



> storm connors wrote:
> > Why would you hook up an Iota such that it was exposed to charging voltage?
> 
> There are two common ways to wire a DC/DC.
> ...


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## EVDL List (Jul 27, 2007)

*Re: [EVDL] question about DC 2 CD converter*



> On 27 Jul 2008 at 18:11, storm connors wrote:
> 
> > Why would you hook up an Iota such that it was exposed to charging voltage?
> 
> ...


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## EVDL List (Jul 27, 2007)

*Re: [EVDL] question about DC 2 CD converter*



> Neon John wrote:
> > A reasonable limit is pretty easy to calculate. Assume line voltage
> > plus 20% or 144 volts AC. The peak of that is 203 volts. I believe
> > that those caps are in series.
> ...


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## EVDL List (Jul 27, 2007)

*Re: [EVDL] question about DC 2 CD converter*



> Lee Hart <[email protected]> wrote:
> 
> >Neon John wrote:
> >> A reasonable limit is pretty easy to calculate. Assume line voltage
> ...


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## EVDL List (Jul 27, 2007)

*Re: [EVDL] question about DC 2 CD converter*

>> 1000uF at 200vdc. So 203v is beyond their voltage rating.



> Neon John wrote:
> > Not enough that I'd lose sleep over, though.
> 
> To each his own. I prefer stuff that doesn't break. If something does
> ...


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## EVDL List (Jul 27, 2007)

*Re: [EVDL] question about DC 2 CD converter*



> Jeff Shanab <[email protected]> wrote:
> 
> > If I drive home at night the aux battery may get low, letting it finish
> > chargeing while I charge the main pack is convienent. I don't have to
> ...


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## EVDL List (Jul 27, 2007)

*Re: [EVDL] question about DC 2 CD converter*



> Lee Hart <[email protected]> wrote:
> 
> >>> 1000uF at 200vdc. So 203v is beyond their voltage rating.
> >
> ...


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## EVDL List (Jul 27, 2007)

*Re: [EVDL] question about DC 2 CD converter*



> storm connors wrote:
> > None of the reasons for keeping the DC/DC on all the time strike me as
> > justifying the liabilities for doing so.
> 
> ...


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## EVDL List (Jul 27, 2007)

*Re: [EVDL] question about DC 2 CD converter*

The more I see this the more it bothers me...... What is the battery for?
You have a DC to DC capable of supplying enough power to run all the 13.8
volt appliances, just let the inverter do its job and leave the battery at
home. If the IOTA is not reliable enough to be trusted to live for 5 to ten
years I'd be looking for a better one. 

Mark Grasser
Eliot, ME

-----Original Message-----
From: [email protected] [mailto:[email protected]] On Behalf
Of Lee Hart
Sent: Monday, July 28, 2008 8:49 PM
To: Electric Vehicle Discussion List
Subject: Re: [EVDL] question about DC 2 CD converter



> storm connors wrote:
> > None of the reasons for keeping the DC/DC on all the time strike me as
> > justifying the liabilities for doing so.
> 
> ...


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## EVDL List (Jul 27, 2007)

*Re: [EVDL] question about DC 2 CD converter*



> Lee Hart wrote:
> >> To each his own. I prefer stuff that doesn't break. If something
> >> does break, I fix it so it won't break again.
> 
> ...


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## EVDL List (Jul 27, 2007)

*Re: [EVDL] question about DC 2 CD converter*



> Mark Grasser wrote:
> > The more I see this the more it bothers me...... What is the battery for?
> >
> A) Lets the emergency flashers work even after you've blown the fuse on
> ...


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## EVDL List (Jul 27, 2007)

*Re: [EVDL] question about DC 2 CD converter*

john...im curious as to which controller you would use for a 144V stack
(24 us145's) an ADC 9.1 (4001A) on a small pickup.....and some 'whys' 
would be a big help too....

thanx in advance....

lyn

Quoting Lee Hart <[email protected]>:



> > Lee Hart wrote:
> >>> To each his own. I prefer stuff that doesn't break. If something
> >>> does break, I fix it so it won't break again.
> >
> ...


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## EVDL List (Jul 27, 2007)

*Re: [EVDL] question about DC 2 CD converter*



> [email protected] wrote:
> 
> >john...im curious as to which controller you would use for a 144V stack
> >(24 us145's) an ADC 9.1 (4001A) on a small pickup.....and some 'whys'
> ...


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## EVDL List (Jul 27, 2007)

*Re: [EVDL] question about DC 2 CD converter*

Lee,
You are confusing me. I originally set up the system with a 13.5v full
time float charge. You commented that that would result in the battery
losing capacity which prompted me to go to the 14+ volt when running
option. Truth be told, I don't see where the battery will ever be
discharged significantly. The Iota 55 should produce enough power to
run lights, wipers, and heater blower. With no big starter draw like
in an ICE vehicle, the battery should never need much charging. The
Trimetric used for monitoring draws so little power that it shouldn't
affect the battery state of charge unless I left the vehicle unused
for weeks.

I guess the question I really have is whether I should use the 14+v
setting or if the 13.5 wouldn't be enough when used only when the
vehicle was operating.



> Lee Hart <[email protected]> wrote:
> > storm connors wrote:
> >> None of the reasons for keeping the DC/DC on all the time strike me as
> >> justifying the liabilities for doing so.
> ...


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## EVDL List (Jul 27, 2007)

*Re: [EVDL] question about DC 2 CD converter*



> storm connors <[email protected]>wrote:
> 
> > With no big starter draw like
> > in an ICE vehicle, the battery should never need much charging.
> ...


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## EVDL List (Jul 27, 2007)

*Re: [EVDL] question about DC 2 CD converter*



> storm connors wrote:
> > Lee,
> > You are confusing me. I originally set up the system with a 13.5v full
> > time float charge. You commented that that would result in the battery
> ...


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## EVDL List (Jul 27, 2007)

*Re: [EVDL] question about DC 2 CD converter*

I follow your calculations, but isn't the DC-DC converter ( if there is one) generally sized big enough to absorb that 15 amp load, just like the alternator does in an ICE car? 

I always thought the aux battery only came into play during start-up ( to activate the relay(s) to get the car - including the DC-DC converter - operating, and during emergency situations - like a DC-DC converter failure, or a blown fuse in the main pack, that could otherwise leave you in the middle of the road with no lights.

Phil

> Date: Sat, 2 Aug 2008 21:49:44 -0600
> From: [email protected]
> To: [email protected]
> Subject: Re: [EVDL] question about DC 2 CD converter
> 
>


> storm connors <[email protected]>wrote:
> >
> > > With no big starter draw like
> > > in an ICE vehicle, the battery should never need much charging.
> ...


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## EVDL List (Jul 27, 2007)

*Re: [EVDL] question about DC 2 CD converter*

True... but it depends on the EV too... I've seen ones with the DC-DC
converted sized just like an alternator would be, to handle the loads, but
the battery is still there to smooth out surges and in case the DC-DC failed
or a main pack fuse blew. And in my opinion, that's the correct way to do
it... but I've also seen it without any DC-DC at all... using a deep cycle
auxiliary battery that is recharged from AC when the main pack is recharged,
and ones where no battery is used at all, just a DC-DC.

FWIW, I also had an old ICE that the generator went out on, and we ran it
for about two weeks just charging the battery separately, till we could
order in the new generator... it only drew about 2.5 amps when running (we
only drove it during the day, on backroads, so we didn't use the
headlights), and we could crank start it if the battery got too low to turn
the starter.



> Phil Marino <[email protected]> wrote:
> 
> >
> > I follow your calculations, but isn't the DC-DC converter ( if there is
> ...


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