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Voltage Booster Fuse for AGM batteries


RainGoat
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Voltage Booster Systems for AGM batteries are pretty popular on the Toyota forums. Here is just a quick YouTube explaining a fix for a 5th Gen 4Runner. Does anybody know if there is a similar fuse slot for the R50.

 

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Honestly don't think that it really matters. AGM batteries have lower internal resistance than conventional wet cells. The higher charging voltages on the label are generally for external charging within certain conditions. 

I have been running AGM batteries in all my autos for over 20 years and haven't had any issues from operating alternators according to the battery testers. I do try and do an external charge and equalization a couple times a year to keep them healthy. 

I don't believe the R50 has an ECU control on the charging system, I believe it is all contained in the regulator built into the alternator. If you want to try it out, get the fuse and replace the alternator fuse in your fuse box. Doubt there will be a noticable change. 

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Voltage Booster Systems for AGM batteries are pretty popular on the Toyota forums. Here is just a quick YouTube explaining a fix for a 5th Gen 4Runner. Does anybody know if there is a similar fuse slot for the R50.
 

I didn’t watch the while video but that sort of seems gimmicky like those universal ecu tuners that plug unto the obd port. Not sure why that guy would need any sort of voltage booster when he’s running a x2 (relabeled northstar) battery. Those are the best money can buy.


Sent from my Pathfinder
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So, I concur that I’ve run Optima, which are rolled gel mats without ever worrying about it. My initial Red Top lasted forever - like 8 years, notably less on the follow up Yellow Tops but I see that as simply chronicling the decline of Optima. I now have a X2 Power AGM & I’ve actually checked it as I maintain it with an Optima battery charger. It doesn’t ever get up into the 14s anymore. There are multiple products available for “Overlanders” to increase voltage in Toyotas, specifically T4Rs since that’s what I follow. They usually aren’t cheap either - like $80-100. I honestly don’t understand what they’re trying to say so I’ve let it be (I also don’t have an AGM in the T4R yet). I’ll see if I can another & post it just to see if anyone knowledgeable in battery science & electricity can explain or understand it. 

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50 minutes ago, RainGoat said:

The first line in the article is not correct about needing higher voltage.  As Mr. Reverse pointed out the charging voltage for wet cells and AGMs are almost identical, so there is no need for a higher voltage.  I also agree with R50JR that it is an unnecessary gimmick, especially if we do not know whether the Pathy ECU actually controls the alternator output.

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I think what these guys are are doing is dropping the voltage to the alternator's "sense" wire. That wire goes from the battery to the alt's regulator to tell it what the battery voltage is (which is how the alt knows how hard to work). If you can make the alt see a lower voltage than what's at the battery, it'll charge harder to compensate. That GM part number comes up as a diode (not a fuse), and the Arclight product looks like two diodes on a circuit board. Diodes have a forward voltage (typically 0.6-0.7v), so I think what they're doing here is adding those diodes in line with the sense wire, causing the regulator to think that the battery voltage is lower than it is. If this mod works the way I think it does, either the GM diode or the Arclight on its low-boost setting would give you a 0.6-0.7v increase at the battery, and the Arclight's high boost (which I assume puts the two diodes in series) would give you a 1.2-1.4v increase at the battery.

 

Comparing the output voltage spec in the '03 R50 manual (14.1-14.7v) to the 4Runner output shown at the start of the first video (13.6-13.7), it looks like the 4Runner owners are doing this mod to achieve the charging voltage that yours already makes. Century's website suggests 14.6-14.8v, so your charging system is probably right about where it needs to be already. If it's towards the low end of spec, you could probably boost it using the same method (looks like the R50 has a conventional alt and the same 7.5a fuse on the sense wire), but if it's working now, it's probably not worth messing around and potentially boosting it too far. Worst case (high end of spec plus an Arclight at full chooch) would be pushing 16v. At least the Arclight has a fuse, though--as clever as the GM diode mod is, unless that diode happens to pop at around 7.5a, that circuit isn't properly fused anymore.

 

As an aside, why do people making Youtube videos think they need a backing track while they're talking? And why does that one sound like an ice cream truck with something wrong with the cassette deck?

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@Slartibartfast Fantastic! That’s exactly the kind of explanation I was hoping to receive. I’m also particularly grateful for the warning on the GM diode as I’m likely to replace our original T4R battery with an AGM in the next year. 
 

I think I’ll look at taking occasional measurements on both trucks in the interim. I’ve been wanting to put a dash voltmeter in both anyhow.

 

While I’ve got you, my Mom’s truck had the winch installed with a full bumper installation & I can’t seem to see any fuse between the winch & the battery. It’s thick gauge wire but it’s been bothering me as I was always taught to fuse everything (that said, my electrical knowledge is what I learned in a single high school & college physics course - plus practical home wiring, hence, I have much I don’t know). Curious on your thoughts on that?

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You won't find a fuse for the winch power due to the high current draw of the motor under load. Much like the starter motor but winch motors pull more and much longer than starters. That is why many winch install kits have a shut off switch near the battery. It is possible there is a high amp breaker switch somewhere in the circuit. 

My current battery in my Pathfinder is a large(group 48?) AGM made by Deka but branded as Duracell from Sam's club. $160 with 3 year free replacement warranty was hard to beat for an AGM that seems to get good reviews from the boating world. I added a voltmeter many years ago to my truck and have observed voltages running everywhere from 13v to almost 16 with it and I know the alternator charging control is completely in the built in regulator in the alternator. My alternator is from a late 90s Quest, so has twice the current output than the stock unit my truck had. I did up size the charging cable when I observed the original smoking while I was jump starting a truck shortly after the alternator upgrade, but other than that, basically stock and has been working fine for more than 15 years. 

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I haven't set up a winch on a truck, but I've wondered about fusing them too. I did a little poking around and it looks like there's some debate as to the "right" way to do it. Some people just run it straight to the battery (like the starter, which isn't fused either) and call it good. It's simple, and simple is good, but it means you're gonna have a bad time if the cable rubs through or gets pinched in an accident. The risk of it shorting out can be mitigated with careful routing, but you also don't have an easy way to kill power to the winch if something goes wrong, which strikes me as sketchy. Some people run a manual shutoff switch or a relay between the cable and the battery. You can also get circuit breakers that these guys seem to like, which can be turned on and off manually but also click off if overloaded. The breaker seems like a great idea to me, provided it's properly sized so that it won't click off during normal use, and provided it can handle life in the engine bay. One commenter raised the concern of what happens if you're in a sketchy situation off-road and your breaker trips and leaves you hanging, which could be a reason to go for the basic switch over the breaker, depending on how hard your mom intends to send it.

 

+1 for the voltmeter, that should give you a better idea of what you're up against.

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2 hours ago, Mr_Reverse said:

You won't find a fuse for the winch power due to the high current draw of the motor under load. Much like the starter motor but winch motors pull more and much longer than starters. That is why many winch install kits have a shut off switch near the battery. It is possible there is a high amp breaker switch somewhere in the circuit. 

My current battery in my Pathfinder is a large(group 48?) AGM made by Deka but branded as Duracell from Sam's club. $160 with 3 year free replacement warranty was hard to beat for an AGM that seems to get good reviews from the boating world. I added a voltmeter many years ago to my truck and have observed voltages running everywhere from 13v to almost 16 with it and I know the alternator charging control is completely in the built in regulator in the alternator. My alternator is from a late 90s Quest, so has twice the current output than the stock unit my truck had. I did up size the charging cable when I observed the original smoking while I was jump starting a truck shortly after the alternator upgrade, but other than that, basically stock and has been working fine for more than 15 years. 


I've only ever fitted a shutoff to prevent current draw when not in use & for security. Here in Aus we had a spate of guys unspooling people's winches, running the cable over the roof of the car to the rear bumper, engaging them and effectively crushing the roof in on someone's car while they slept. 

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On 7/14/2020 at 6:44 PM, Slartibartfast said:

I haven't set up a winch on a truck, but I've wondered about fusing them too. I did a little poking around and it looks like there's some debate as to the "right" way to do it. Some people just run it straight to the battery (like the starter, which isn't fused either) and call it good. It's simple, and simple is good, but it means you're gonna have a bad time if the cable rubs through or gets pinched in an accident. The risk of it shorting out can be mitigated with careful routing, but you also don't have an easy way to kill power to the winch if something goes wrong, which strikes me as sketchy. Some people run a manual shutoff switch or a relay between the cable and the battery. You can also get circuit breakers that these guys seem to like, which can be turned on and off manually but also click off if overloaded. The breaker seems like a great idea to me, provided it's properly sized so that it won't click off during normal use, and provided it can handle life in the engine bay. One commenter raised the concern of what happens if you're in a sketchy situation off-road and your breaker trips and leaves you hanging, which could be a reason to go for the basic switch over the breaker, depending on how hard your mom intends to send it.

 

+1 for the voltmeter, that should give you a better idea of what you're up against.

Marine breakers should fit the bill:

Marine high amp breaker switches

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With the heavy gauge cabling used to power a winch, even in the unlikely event of a dead short, the chance of fire is pretty low. The heavy cable usually can handle more amps than the battery can provide for the short time before the battery has an internal melt down killing it. In the grand scheme of things, a battery isn't particularly expensive, often less than a tire, and if a little care is used in the winch install, chances of a dead short are pretty small as well. Like everything else in life, it is a balancing act of, cost vs effectiveness vs practical. We each have our own levels of risk we are comfortable with in everything. Myself to example, the Covid virus doesn't worry me and I am high risk due to severe asthma from birth. I don't bother with a mask, gloves, and sanitizer. I use soap and water and just go on. Seems to have worked for me even though I spend 50+ hours per week in other people's cars. However I am less confident in people around me, so I carry at least one loaded firearm with at minimum, a full reload pretty much all the time. Seems odds are more likely I will catch the virus and suffer harm from it than be attacked by someone, but that is just me and my fears. 

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