ISIS Power Parasitic Draw

As a heads up - if one does not run the car about every two weeks or so your battery will be dead. I have attached a battery maintainer to an accessible permanent car mounted cord/connector but then again have forgotten to attach the maintainer on occasion .... dead.

Isis does sell an ISIS InReserve kit at $205.00 dollars and I guess there's a reason for that. Too bad they didn't somehow work a cut-off system into their normal product. If your car is a daily driver it's a non-issue - but who puts an ISIS system into a commuter car.

Wouldn't surprise me - the I2 (it's predessor) also liked to slurp on the battery.

Solution is easy though - battery cut off switch ... I throw mine every time I'm done driving. No way am I letting power stay connected to something I built, haha!

I have both a permanently mounted battery maintainer on the car, as well as the InReserve. I think one or both of those solutions is the right way forward for the non-daily driver.

My battery maintainer is hooked up to a marine charger terminal so you can just plug a standard extension cord right into the car to keep the battery topped off. Just make that a habit when you park your car in the garage at night.

The Corvette guys have a similar problem with cars they don't drive often, and some have found a magnetically attached power cord (driving a maintainer) to be a solution.

Here is the model I use. Ctek 3300 CTEK Battery Chargers - The World's Smarter Battery Charger Many high end manufacturers use them as well. They usually go on sale for around $50.

Having experienced this problem on my “occasionally used” Corvette Conversion; I plan on solving the problem the same way on the SLC and install a on board battery maintainer and splicing the AC power cord to a marine style weather proof male pin connector which will be mounted on a frame rail at a easily accessible location at the rear of the car. The connector comes with a water proof cap and a chain to protect the connectors when not in use. When parked a Remke heavy duty power cord with a female pin connector will be plugged into the car.
Remke Mini-Link Molded Cord Connectors in TPE, Rubber and Plastic


In the past, I have used a Model #2012 12V Battery MINDer Charger/Maintainer/Desulfer from Northern Tool; however, after seeing the compact size of the CTEK MUS 4.3 unit at the same price, I may just change my mind and go with the CTEK.
Jim
batteryminder from Northern Tool + Equipment

If a Master Disconnect Switch is used, would this replace the need for the "InReserve"? It seems to me the down side to these two systems are that when the battery is disconnected or is shut down, that the clock, etc. will have to be reset when the battery power is returned. It would seem a battery tender would be better so that power is never lost?

BTW- is a 2 post battery disconnect ok or is there a reason for a 4 posts?

The biggest problem with disconnecting power would be with the ECM. It will have to relearn it's fuel trims and other features. It takes a day or two of driving to get caught up.

mcfling said:

If a Master Disconnect Switch is used, would this replace the need for the "InReserve"? It seems to me the down side to these two systems are that when the battery is disconnected or is shut down, that the clock, etc. will have to be reset when the battery power is returned. It would seem a battery tender would be better so that power is never lost?

BTW- is a 2 post battery disconnect ok or is there a reason for a 4 posts?

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Normally one would wire the car such that "permanent" 12V power to the ECU, a clock or other things that have a volatile memory would not be switched off when either the InReserve or a master switch was used.

The purpose of the InReserve is as a backup, in case you forget to use the master switch, or connect your maintainer, or drive the car frequently. Then it operates to save the battery that would have otherwise been drained.

Yup, I ran into the mysterious dead battery a couple weeks ago as well. ISIS drained my brand new Odyssey 925 down to 11.5VDC in just a few days. As a result, my motor wouldn't turnover. By contrast, I've had a Odyssey 925 in my Hot Rod for 3 years with out a problem. It sits sometimes for more than a month without a maintainer and it starts every time.

I noticed long ago that there was a spark when connecting the ISIS to battery power. I asked ISIS Tech Support about it and they said the spark was due to the initial charging the capacitors in ISIS, but then the system draws just about no juice.:deal:

I was hoping to use the ISIS security system, but I think that resets once you turnoff the ISIS power with the battery cutoff switch.

KENS80V said:

The biggest problem with disconnecting power would be with the ECM. It will have to relearn it's fuel trims and other features. It takes a day or two of driving to get caught up.

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But once you've tuned the ECU on the dyno it's not learning, is it? You've already set what the parameters it should use are.

EFNFAST said:

But once you've tuned the ECU on the dyno it's not learning, is it? You've already set what the parameters it should use are.

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Even with tuning, the ECM will lose its long term fuel trims with the loss of constant battery power.
A good solution is to wire the ECM battery, and clock memory to the battery side of the master disconnect switch, so they stay energized, when the switch is turned off. Then you don't have to keep a charger hooked up all the time.

marine external plug outlet -- good catch, I would of never....

Here's a link https://www.pegasusautoracing.com/productdetails.asp?RecID=1464 with a .pdf link (read it) regarding the 4 post battery cut-off switch and it's proper connection. It basically saves the alternator and cuts the power to a running engine.