Designing the ultimate grid charger

[Mr. Mik]

The power supply datasheets all mention a 127VDC to 370VDC (or larger) input possibility.

I just don't know if anything else in you design needs AC to function.

Mik

[RobertSmalls]

There is a federal PHEV tax credit that applies to new cars with >5kWh battery capacity.

There's also this, which might be a 10% tax credit for PHEV conversions: Federal 10% Tax Credit For Conversion! Enginer | Hybrid Plug In

[Mike Dabrowski 2000]

Nothings else needs ac, So it looks like the things would run on DC.
Cool.

[Mr. Mik]

Originally Posted by Mike Dabrowski 2000

...
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My opinion about the best output configuration is shown here, where I will document the charger development.

MIMA Honda Insight Modified Integrated Motor Assist - Building a hybrid car grid charger
this configuration puts the diodes and fuse in the car right next to the positive connection point at the precharge resistor. The fuse has minimal voltage drop, so the true battery voltage is read, and the 100K resistor offers isolation to the measuring circuit without the temperature dependent diode drop ....
...

On your blog: Why do you show one board with fuse, resistor and 1 diode - and another board with 2 diodes?

I wonder if a soldered 2A fuse is a good choice. I always manage to blow fuses.....

My particular concern is the inrush current: 30A + 36A +35A + 30A = 131A

I am not sure how they are calculated, but I would think they are additive in this setup?

And I do not know how often you can put this sort of inrush current through the fuse you are looking at.

I had a look at the specifications and if I read the time-current curves correctly, the fuse would blow after 0.06sec at 15A.

But I would feel more confident with a replaceable fuse. I used this one in my Prius NHW10 "Special Freddy" charger: http://au.farnell.com/littelfuse/047...71?Ntt=1757471 and this fuse holder: http://au.farnell.com/bulgin/fx0296-...351?Ntt=319351

Mik

[Kevin Dougherty]

This is what I found through Google

New Energy Tax Credit for Plug-in Hybrids Purchased in or after 2010

Haven't read it, but I will this weekend...got to go to work!

[Mike Dabrowski 2000]

The single diode is for the 350MA unit, the dual diode board is for the overnight dual rate charger which has a 700ma and 350ma CC supply, thus the two diodes.

Your confusing the input fuse from the output fuse, there will be no inrush current on the output fuse, due to the constant current supplies.

I like the fuse you specified though, and found that Mouser has them for under a buck
04773.15MXP Littelfuse Fuses
I think I will use those instead of the surface mount, and see if I can find an inline fuse holder for them.
May as well go with the replaceable fuse just in case.

[Mr. Mik]

Originally Posted by Mike Dabrowski 2000

The single diode is for the 350MA unit, the dual diode board is for the overnight dual rate charger which has a 700ma and 350ma CC supply, thus the two diodes.

I was told, and my own very limited experience seems to confirm this, that it is better to use a single diode with a higher current rating. As the diodes heat up, their voltage drop reduces. If one heats up more than the other, this can lead to a runaway-current-like situation, where most of the current flows through one diode which gets hotter and hotter. I would just use a single diode rated for 6A or so.
Edit later on: I might end up slapping myself again (see below, call me Dobby if you like!)...you will be connecting the two current limiting power supplies to separate diodes???....never mind, I'll shut up now!

Your confusing the input fuse from the output fuse, there will be no inrush current on the output fuse, due to the constant current supplies.

>>Sound of slapping my face.....<< You are of course right!

But good to know and to remember this anyway, because it would blow the tab fuses in my Vectrix pack if I were to use it to power the charger without an inrush current limiter. What a nice idea: A Vectrix EQ charger that can also be powered by the Vectrix, and then be used to "rescue" charge any hybrid (and most EV's) out there!

I like the fuse you specified though, and found that Mouser has them for under a buck
04773.15MXP Littelfuse Fuses
I think I will use those instead of the surface mount, and see if I can find an inline fuse holder for them.
May as well go with the replaceable fuse just in case.

At least my embarrassing brain fart was not totally useless then!

Mik