[Overlander23]

The Iota DC->DC converters have a "charge plug" that can be inserted to up the output voltage from 13.6v to 14.2v. I'm using an Odyssey PC625 AGM as my accessory battery.

Should I be running at the Iota at the higher 14.2v output to simulate an alternator? Or the lower 13.6v float level?

When the the ignition in my vehicle is off, everything shuts off including the converter.

 

[Overlander23]

Ooookay... I'm going to run the Iota in "charge" mode (charge pigtail in) to output 14.2 volts, theory being that this is closer to what a regular alternator would put out... It's also what Odyssey refers to as a "cycle" charge voltage rather than "float" voltage.

 

[m38mike]

Are you running with your headlights on or off? Do you have any other large power drains on your 12v batt? (heater, stereo?) If you don't have a big drain on the batt, then I would think that the 13.6v would be sufficient. If you have a bid drain, then go with the 14.2v.

My 2 cents.

 

[etischer]

Are you running with your headlights on or off? Do you have any other large power drains on your 12v batt? (heater, stereo?) If you don't have a big drain on the batt, then I would think that the 13.6v would be sufficient. If you have a bid drain, then go with the 14.2v.

My 2 cents.

You might measure the voltage at the battery. With the head lights on I loose about 1/2 a volt in the wire, so I run 14.2 with the ignition on.

 

[EVfun]

If the DC to DC converter is only on when the vehicle is on then 14.2 would be more appropriate. If the DC to DC converter is always on 14.2 will slowly cook the battery. It it is always on you need to use the recommended float voltage.

 

[gdirwin]

I have a 90A version - lots of big 12V loads (P/S pump/vacuum pump/seat heaters etc...).

I have a 12v relay that connects the shorting pins only when I am driving - increases the voltage, brighter headlights etc...

When I am charging the main pack, the DC/DC is also connected (so the 12V battery also gets charged) but at the normal/lower level.

I also found (from this forum) that the IOTA will drain your 12V battery when not in use - I used a contactor to disconnect the IOTA from the 12V system when everything is off.

Also be sure to see the IOTA ruggedizing page:
http://www.evdl.org/pages/iotamods.html
I have not done this yet, but it is on the list (probably wait for it to die first, then fix it properly).

IOTA also has an IQ4 smart charger device:
http://www.iotaengineering.com/iq.htm - anyone know how this could be used in this mix? Doesn't seem useful at this point...