The NorthStar AGM Battery + Voltage Booster Upgrade

Almost as good as the time USPS delivered my axle shims, minus the shims.. They delivered an empty package with a hole in the side and didnt think anything of it

 

Got my voltage booster installed. Thanks for the write up @crashnburn80.

 

Tell me more about that dual USB port...

 

$14 MICTUNING 36W Fast PD USB-C Car Charger with USB Quick Charge 3.0 and Type C Charger Socket with LED Digital Voltmeter Compatible with iPhone Pixel Samsung

https://www.amazon.com/MICTUNING-Ch...ith+USB+Quick&qid=1567051501&s=gateway&sr=8-1


That link should work... it’s a fast charge usb-a and usb-c charger. It was cheap. Actually charges fast and installs rather easy. Plus it has a voltmeter...

I removed an oem 12v cigarette lighter plug, tinkered briefly with the little wire harness (the oem plugs have male spade connectors at 90°, the female spades are clipped into a L-bracket. They can be removed and plugged into the new charger). The original hole needed to be enlarged just slightly to get it to fit. I used a utility knife. Not including dash disassembly, it took 5 minutes.

Be warned though...taking the dash apart to get to that spot is a huge hassle. As I recall you have to remove the center console, the panel below and at the instrument cluster, as well as the radio panel before you can even get to that panel. I could be wrong. It took like an hour for me to get at that panel since I had never done it before. Then like five minutes to install the charger.

https://www.tacomaworld.com/threads/step-by-step-complete-dash-disassembly-with-pics.405055/

 

$10 LIHAN Dual USB Car Charger, 4.8A Output, 12/24 Volt USB Adapter Plug for Cigarette Lighter Voltage Meter, Compatible with iPhone,iPad, Samsung Galaxy, LG, Google, Silver

https://www.amazon.com/LIHAN-Charger-Display-Voltage-Compatible/dp/B01JA627KU Lol, this looks way easier.

 

Easier yes. But now I know how to take apart the dash, which is helpful since I’m in the process of adding switches. And I like the hardwired option. Cleaner is better.

Besides. Think of all the character I’ve built.

Oh and it turns out you can partially remove the radio panel and just reach behind this panel. Easy peasy

 

I’m all about that character building

 

+1 to all of this.

 

Good post, given that I'm only an engineer and not a vehicle design engineer like you, can you confirm I understand correctly how this works - the voltage booster simply modifies the signal going to something in the vehicle charging system that is monitoring the voltage? How does the charging system in a vehicle monitor and increase the voltage?

 

Correct. The voltage regulator in the alternator controls the voltage to a specified window, typically 13.5-14.5v. The booster artificially reduces the voltage read by the regulator by 0.5v, causing the regulator to compensate by turning up the voltage 0.5v to meet its specified operating window. It is a very simplistic system really. In 3rd Gen the voltage regulation is managed by the ECU and the alt-s circuit was removed.

I’m not an EE, so I’ll just copy/paste this info below on how a voltage regulator works.

“The voltage regulator controls the field current applied to the spinning rotor inside the alternator. When there is no current applied to the field, there is no voltage produced from the alternator. When voltage drops below 13.5 volts, the regulator will apply current to the field and the alternator will start charging. When the voltage exceeds 14.5 volts, the regulator will stop supplying voltage to the field and the alternator will stop charging. This is how voltage output from the alternator is regulated. Amperage or current is regulated by the state of charge of the battery. When the battery is weak, the electromotive force (voltage) is not strong enough to hold back the current from the alternator trying to recharge the battery. As the battery reaches a state of full charge, the electromotive force becomes strong enough to oppose the current flow from the alternator, the amperage output from the alternator will drop to close to zero, while the voltage will remain at 13.5 to 14.5. When more electrical power is used, the electromotive force will reduce and alternator amperage will increase. It is extremely important that when alternator efficiency is checked, both voltage and amperage outputs are checked. Each alternator has a rated amperage output depending on the electrical requirements of the vehicle.”

 

@115k miles my OEM battery finally took a dump on me, looks like i'll be upgrading to this northstar 27f w/ voltage booster. Appreciate the write up @crashnburn80 !

FYI, for anyone on the fence about this, looks like batteries plus is offering 20% off on car batteries when you buy online and pick up in store so needless to say i just bought mine

 

Could someone explain why the spec’d voltage for the Northstar AGM is 14.4-14.8, but it is okay to only hit that spec during cold startup (because it drops to 13.x after warmup)? How does the alternator meet the requirement when the majority of its output is well below the stated spec? Is the short cold startup time enough to accomplish a proper charge with regards to voltage?

 

That is the specified cycle charge voltage, basically if the battery doesn't need charging then it doesn't need to operate at that higher voltage. The starter is a high draw device that takes some capacity of the battery to operate. After the vehicle is started the battery is replenished by the alternator at charge voltage, and once the battery is topped off the voltage drops and the alternator handles the primary electrical loads of the vehicle. If you further reduce the reserve of your battery by running a winch, powerful lights, compressor ect either when the vehicle is off or exceed the output capacity of the alternator when the vehicle is on, then that cycle charge duration may be much longer as the batteries reserve supply is refilled.

 

So the alternator voltage will stay at the higher end (~14 stock or ~14.5 with booster) until fully charged? Voltage regulator? I thought it was just temperature/time dependent, as in letting it sit overnight vs going to a movie and coming back to a warm engine.

 

Yes, the Voltage Regular will keep the charge voltage high until it determines the battery is fully charged and turn down the voltage. If you look at the charts in the original post, you can see the battery holds some additional voltage after the truck turns off that bleeds off over several hours before stabilizing. All the booster does is move the entire baseline up 0.5v to be in the appropriate range of an AGM.

 

As usual, very helpful @crashnburn80. Thank you!

 

Booster for sale, no association:
https://www.tacomaworld.com/threads/hkb-voltage-booster.629273/

 

Snagged it, thanks for the heads up!


The initial peak voltage seems to be more than the rated 0.5v boost (going from 14.1v stock to 14.9v with the MK2 booster).
I need to get my AGM installed so I can run it longer and see what it settles down to. Didn't want to run it for more than a couple minutes at the higher voltage with the stock battery in there.
(I'm also using a cheapo multimeter... so these numbers could all be garbage)

Been planning to put the Northstar 31M in there for awhile, but all the photos of cracking metal have got me leaning toward the 27 size now.
Do we know if there's any difference between the 27F and 27M batteries?
https://www.batteriesplus.com/product-details/auto_light-truck/battery/x2power/sli27fagmdp
https://www.batteriesplus.com/product-details/marine_rv/battery/x2power/sli27agmdpm

The specs online are virtually identical except that the 27M has 2 extra posts. If they have the same internal construction and deep cycling ability, the 27F is significantly cheaper ($45 difference after discount).

 

14.9v is definitely higher than you should be getting. Voltage does fluctuate a good amount from the alternator though, but shouldn't be that high. You are super local, I'd be happy to help you out with the reading if you want. Have you been to the local brewery meetups? Your camper setup looks familiar.

As to the 27M, I'm pretty certain they are identical but the M has extra top posts for boat/RV accessory power.

 

I made it to a couple of the meetups last year, but haven't been in awhile, might be able to make it to this month's. Gonna grab the 27F and a battery monitor (which should be good to have anyways once I get the solar hooked up on top of my camper).