Help: national luna dual battery problems

[N.Alvarez]

Any input or suggestions here are very much welcome.

I just installed my National Luna Dual Battery system, and installed an Odyssey 25pc 1400 auxiliary battery. Currently still using the oem size battery for the main (interstate) roughly 1.5 years old I believe.

I connected the National Luna system according to the instructions & made sure to firmly crimp & heatshrink all connections.

Upon starting the car, it turned over for a second, then died. I tried again & it started, and stayed on, however the idle sounded REALLY low/quiet and way lower than normal. I left the car running for 5 minutes (as that's the default timer until the solenoid engages) and all appeared normal via the dual battery system monitor according to the instructions (main battery reading 12.6v & aux fully charged). At this point I disconnected the monitor, b/c I hadn't routed the cable thru to the cabin yet & needed to leave where I was doing the install.

I left the car running another approx. 5min and pulled out of driveway. When I came to a complete stop to put the car back in drive it dropped its idle below 500rpm and then died. I was able to start it again and drove away.

I had a few more times where the battery would die at red lights on my way home, until I figured I'd come to a stop, put it in neutral and keep my foot on the gas and idle it around 1,000rpm until the light was green. This worked until I got home.

Can anyone point out some suggestions to help diagnose this issue? Is this happening b/c it's still a stock alternator & not high output? Prior to installing, I had NO issues starting the car with the main battery.

I will connect the battery monitor again and drive around with it to see what the actual volt read out is when I'm driving and coming to stops.

Anyone have this issue with their dual battery? Or the NL system if your using that?

Thanks!!



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[N.Alvarez]

*This is on my 5th gen 2010*
After checking again, I realize the main battery is over 2 years old. Not sure if that makes a difference....I may look into replacing main battery

 

[Mr.emergency]

This is interesting, I just installed a second battery and blue sea 7622 as an isolator. Upon first start up my 4runner also died, but was easily restarted. It has been idling much lower than usual- like 100-200rpm low. But only when first started and with batteries connected. Running through different possibilities in my head i'm wondering if it might be due to my starter battery being the original battery that came with my t4r (2007 4th gen). I'm wondering if the system normally idles higher because my stock battery isn't retaining charge as it should- but when both batteries are connected, there's plenty of charge so the system is idling much lower than normal. when batteries are connected Ive noticed it also pulls less at full stop in traffic- due to the idle being much lower.

Wonder if anyone else has encountered this.

 

[fourwd1]

A 2 yr old battery should not be an issue.
I think the "high tech" isolator may be.
I use a simple relay to isolate the 2nd battery on my 83, never a problem.

 

[N.Alvarez]

Thought I'd give a follow up. After more searching around and double checking my connections, turns out the NL system is doing whats its supposed to. Evidently when I had the main battery terminals disconnected, this "erased" the the ECU idle memory. I read that it needed to "re-learn" and return to normal idle speed in a few days. I decided to clean out the throttle body & MAF as well, as I don't think the previous owner had done that yet. So yesterday I cleaned the throttle body & MAF, drove around for 20minutes and happy to report all is back to normal. Also, definitely notice an improvement in throttle response, as the throttle plate was really gunked up, hadn't been cleaned in 95K miles.
[MENTION=111415]Mr.emergency[/MENTION] , I'd recommend doing the same procedure and seeing if that clear up your problem as it did for mine.

 

[fourwd1]

Glad you solved the problem!