The NorthStar AGM Battery + Voltage Booster Upgrade

I'd just looked it up on Amazon and it shows it does have an AGM mode.

So my next question would be: How often are you suppose to charge your AGM battery? Every night at the end of your day?

 

I want to say I have a Noco 3500. Has all the modes I would need for the different batteries in my fleet. Been a while since I looked, but I want to say there were "smaller" aka cheaper models that still have the cold/AGM mode.

And now that I have a booster in the truck, I don't use the charger too much any more.

 

Thanks for the info, very helpful.

 

Well there ya go. I did mine once a month before I got the booster.

 

I believe this model is the newer/smaller version of what you have.

 

I'm getting 13.2-13.9 volts on my Ultraguage for ECM voltage. When I put the multimeter on the battery terminals I'm getting 12.65 volts at idle. Why the discrepancy? Can someone explain?

 

I got the fixed voltage fuse and now I'm running it. My voltage was always in the range (startup) 13.8-13.0, and I'm running two AGM batteries with IMS battery isolater which I love. now it runs 14.5-13.9 and definitely charges my failing AGM much faster on shorter trips. My factory headlights with upgraded bulbs are definitely brighter, and I swear the interior dash is brighter which I run at high. I wish I had done this sooner and maybe my batteries would have lasted longer. It will be interesting when i throw my camping 92lb 155amp hour AGM battery in the mix with my Solar controller and DC to DC charger for the solar panel

 

Go on....

 

check with a different meter to verify first. There should be a higher voltage at the battery than what your ultra gauge is reading. At least from my experience

 

I don't have another meter. That was my understanding also, due to voltage drop, should be highest at the source. Doesn't make sense to me.

 

I dont think anyone ever confirmed if OBDII readers (SGII, Ultra Gauge, etc) read their own voltage based on the OBDII DC supply, or if they read OBDII data from a voltmeter within the ECU itself. Thats a possible source of error, but still your numbers seem way off.

Are you sure you're taking the readings (DMM on batt vs UG readout) at the same time (or as close as possible)? The charging system boosts the voltage after a cold start or in general during cold ambient temps to make up for whatever capacity was used to start the truck. Then it drops off over time as the truck warms up

 

it reads off the ECM not OBDII voltage, you could check the OBDII pin to verify at pin 16.

 

Do you know if thats universal for SGII and UG, or just for the Ultra Gauge?

 

I have no idea, I just went to the UG website and it specified it. "Battery Voltage (Measured by ECM)"

https://ultra-gauge.com/ultragauge/TEN/gauges.htm

 

Ahh nice. Ive looked at SG's website in the past and they dont specifically say

 

Can something be done to increase the charging voltage on a third gen?

 

Still being researched as we speak.

 

Nobody has found a solution yet. In theory if you found the wire the ECU is reading voltage from, you could splice in the booster.

 

My 2nd NorthStar AGM is dying, slowly. Car was having trouble starting, was well below 12VDC by time i looked down at meter. Ive had the booster installed since January, but had battery in previous vehicle with out a booster for over a year. So i dunno, its on charger. Will let it charge for a few days.
So happy it still has a warrantee...

 

Thanks. So I guess there’s no way to reprogram the ECU to make it charge at a higher voltage. Seems like that would be the way to do it if it’s even possible.