^^^

When the charging system gets overloaded (typically only at idle) it's not exactly "game over", the battery then supplies the shortfall. Though it's not impossible, it would take quite a bit to overload the charging system at 2000 rpm.

Also the reason that AGM batteries are called out specifically here is that they require slightly higher that normal charge V for proper operation that typical car batteries.

So there are two subjects being discussed, but the main purpose of this thread was overcoming the slightly low V of the standard charging system which isn't the best for putting an AGM battery in your car.

Thanks for all the replies and insight.

Shortly after I posted, I decided to order a couple of the HKB Electronics Boosters just to see what voltages I would get in various conditions/ RPMS.

The "booster" has not arrived, but I plan on before and after readings, but nothing scientific at this point.

My stock 31M battery finally went click click click today after less than a month of not being on a charger of any sort. I generally top it off every few weeks with a CTEK 7002 on AGM mode. This has been on a stock system with all accessories, dual batteries, and gizmos disconnected (maybe a few 12v GPS/ chargers here and there). The vehicle has been driven ~ 20 miles a day for the past 2 months. Previously I had no trouble with 31M AGM for the past 50K+ miles, but it was driven 500-1000 miles/ week.

I will post more info on the "booster" and my stock settings when it comes in and as I have time.

My stock system my be faulty/ finicky, but I can't see the stock charging system being able to keep up with the 31M battery upgrade, much less a dual battery system.

Disclaimer: I am far from understanding all aspects of electrical charging systems. Other than that in older vehicles, I throw in an HO alternator. isolator system and 2nd battery and it works way better.

Does anyone have any experience with DC-DC chargers in their truck with dual batteries?

Did the HKB booster work for you?

Did the HKB booster work for you? ADVnut.
thinking about ordering it for my new Odyssey Battery 34R-PC1500T .
thanks

Duh, everyone is trying to get more for less.

One hole in your theory is the fact that an automotive alternator doesn't have a constant output current. It depends on the RPMs, regardless of the load.

My HKB fuse arrived today (ordered 4/19, delivered 5/12). My issue was my second battery (AGM) was not charging very well while traveling. I heard about these boosters and thought I'd give it a shot. I'm running the NL smart dual battery controller, OEM starting battery, and Optima blue top 2nd.

https://www.hkbelect.com

Install was supper easy, if you can replace a fuse and run a multi-meter you should be good to go.

Below a pictures of my meter before installation and after:

OEM Battery just after starting no voltage booster



Optima after NL system connects (5min after start)



OEM just after starting HKB voltage booster installed.



Optima after NL system connects (5min after start)


OEM at idle 5min after start with HKB fuse installed.


OEM at 1500 RPM with HKB fuse


Optima at 1500 RPM with HKB fuse


I'll see how this performs this week and report back

Here are some pictures of the install

Fuse itself



Fuse installed



OEM




Sent from my iPad using Tapatalk

Do you have a link to the fuse?

Sent from my SM-G930V using Tapatalk

https://www.hkbelect.com

Added link to my post above, additionally autocorrect changes "HKB" to "HRB"...

@Sleeter , thanks for the write-up and info. This was the info I was looking for when I started the thread and intended to to do. I ordered and received two of the HKB boosters. About the same time, the 270XP alternator group buy started and I went that route instead.

I will admit, I had a "magic beans" thought when I received them.

Glad to see it worked out.

Attached Images

 

How did the 270 work out?

Nowhere near as easy to install as the HKB booster, and way more bloody knuckles. The 270XP wasn't necessarily hard to install, just in a very tight area with hard to reach bolts. I upgraded the wiring as well. I do wish that there was a way to attach the wiring loom as on the stock alt.

With the extra amperage, I also upgraded the Cole Hersee 85amp solenoid on the National Luna to the 200amp solenoid.

Only negative is that right after I installed the 270XP I developed a weird vibration noise only when in drive, stopped, with the AC on. The AC compressor or something is vibrating with the new, larger alternator. It drives me crazy, but hasn't changed in well over 10K miles. It's on my list to address.

I wasn't sold on the booster, wanted to maintain stock. So much for that. Thanks again for your write up!

Perhaps I have read this all wrong, but is this a resistor in place/addition to a fuse, which tricks the charging system into putting out more voltage by giving it a false, low reading from battery voltage? If so, that sounds like a bad idea.

Why not just plug into a shore power charger once in a while to top up the secondary battery?

Smoke and mirrors! Less than a volt difference in all those readings. You don't get something for nothing and in a regulated charging system there is not really any boosting going on. If you feel good about it great - I hope you didn't spend much.

Yeah that's the idea, trick the internal regulator into pushing more volts.
For the last year I could only go 3-4 day long trips before my 2nd battery was almost critical. I'm hoping this allows some charging to take place while I'm traveling. As you can see from the readings my 2nd battery was only receiving 13.65v which is barely enough to maintain the charge under load.

I appreciate your concerns but after researching this solution it appears to very successful across the pacific in Australia.

Any more than a volt difference and it could damage the system. I only need this to help charge my AGM battery, this fuse does not help with total amps if that is someone's particular issue.

I wouldn't call it smoke and mirrors because all it is doing is telling the alternator to push more volts. I'll see how it performs this week and report back.