DC-DC Converter (APM/Advanced Power Module) question

[wizkid057]

Hello,

New to the forum, but, I've been creeping around for a while now.

My question is, does anyone know the true rating for the DC-DC converter in the Volt? I've read some numbers around here, and I know it's fused at 200A, etc... but does anyone know what its actually rated for as far as a steady draw?

I've also run across this dated presentation: http://www.apec-conf.org/2010/images...esentation.pdf

Page 13 says that the DC-DC converter which is "100-200A" and is "Bidirectional". The latter interests me because that would mean there is potential to charge the battery via the DC-DC converter.... ?

But mainly, just want to know how much life I can suck out of the thing.

Any ideas?

Thanks!

-wk

[saghost]

Hello,

New to the forum, but, I've been creeping around for a while now.

My question is, does anyone know the true rating for the DC-DC converter in the Volt? I've read some numbers around here, and I know it's fused at 200A, etc... but does anyone know what its actually rated for as far as a steady draw?

I've also run across this dated presentation: http://www.apec-conf.org/2010/images...esentation.pdf

Page 13 says that the DC-DC converter which is "100-200A" and is "Bidirectional". The latter interests me because that would mean there is potential to charge the battery via the DC-DC converter.... ?

But mainly, just want to know how much life I can suck out of the thing.

Any ideas?

Thanks!

-wk

In a thread a while back, WopOnTour said it was rated for 175 Amps.

[marlow]

which converter are you talking about?

the bidrectional one, would be to and from the motor drive unit,

the one to the 12 volt battery is only one direction and I believe it is the one you are refering to.

[wizkid057]

which converter are you talking about?

the bidrectional one, would be to and from the motor drive unit,

the one to the 12 volt battery is only one direction and I believe it is the one you are refering to.

Was referring to the 12V one. The document I linked was ambiguous and made it sound as if the 12V DC-DC converter would be bidirectional.

175A sounds reasonable. Would be about 2100 watts, minus the draw of whatever else is not able to be disabled... about 400 watts at "idle" I've read?

-wk

[saghost]

Was referring to the 12V one. The document I linked was ambiguous and made it sound as if the 12V DC-DC converter would be bidirectional.

175A sounds reasonable. Would be about 2100 watts, minus the draw of whatever else is not able to be disabled... about 400 watts at "idle" I've read?

-wk

That was my experience - but only 2/3rds of that or so is on the 12V bus (The draw the Traction battery reports exceeds the power reported by the APM by a margin well in excess of the plausible APM efficiency - I assume the Power Electronics have some draw on the HV bus.) We're also getting down into the range where the precision of the reported data limits accuracy...

[WopOnTour]

Was referring to the 12V one. The document I linked was ambiguous and made it sound as if the 12V DC-DC converter would be bidirectional.

175A sounds reasonable. Would be about 2100 watts, minus the draw of whatever else is not able to be disabled... about 400 watts at "idle" I've read?

-wk

Essentially all of the hardware being discussed in that 2008 presentation is referring to the 2-Mode truck power electronics. It's APM actually does have a bidirectional capability for something called "jump assist" that is initiated using a diagnostic scan tool. With a suitable charger connected to the 12V battery, jump assist is used to charge the NiMH batteries to a suitable level that will permit MG1 to start up ICE. (should the RESS become run down for some reason, such as due to a long period of storage)
AFAIK no such jump assist feature on the Volt, although I dont dispute it's APM might still be capable.
WOT

[saghost]

Essentially all of the hardware being discussed in that 2008 presentation is referring to the 2-Mode truck power electronics. It's APM actually does have a bidirectional capability for something called "jump assist" that is initiated using a diagnostic scan tool. With a suitable charger connected to the 12V battery, jump assist is used to charge the NiMH batteries to a suitable level that will permit MG1 to start up ICE. (should the RESS become run down due to a long period of storage)
AFAIK no such jump assist feature on the Volt, although I dont dispute it's APM might still be capable.
WOT

That's interesting. In reading recently, I'd come across this way for a Prius to get stranded - if the traction battery is discharged to the low limit or beyond, it's unrecoverable and they have to plug into a special charger the dealer has to order from Japan (Apparently the main way to get there is to run out of gas, drive until the car stops, and then cycle the power/try to start a few times.)

[larry4pyro]

No numbers on max current, but a good discussion on the DC-to-DC converter at the end of the video mentioned at this link:

http://gm-volt.com/forum/showthread....in-Electronics

[Marcad80]

APM is rated at 165amps at 12 Volts (probably 14.4v) and a max wattage of 2200watts.

This is a great presentation to answer that question and many more.

http://nctcog.org/trans/air/programs...xasMay2011.pdf