The new moulding is now the eye catcher instead of the bronze wheels.
Build 1995 80 series build- a rolling black hole where money disappears
- Thread starter reklund5
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- Thread starter
- #163
Make no mistake- these are definitely reproductions. But like the rest of my truck...it looks great from 10' away!
- Thread starter
- #164
Posted these photos over in @COS80 thread regarding the charge circuit. He'd inquired about using a diode in place of the 7.5A charge fuse to increase the alternator output to more like 14.0-14.5VDC to make AGM batteries happy. In many modern cars, the charge fuse is in the sense wire circuit of the alternator, and adding the diode in the proper orientation increases the alternator output a bit, as the diode has a voltage drop across it. That in turn lowers the voltage on the sense wire circuit, and the alternator charges at a bit higher rate to compensate. This diode trick doesn't work on the 7.5 charge fuse of an 80 series, as that fuse is on the charge warning lamp circuit, not the sense wire. I whipped up a little harness to test a theory without cutting any wires. Using the appropriate connectors and an inline use holder, I made a harness that plugs into the alternator and into the factory harness and adds a diode to that sense wire.
THIS IS AN EXPERIMENT and I'm not recommending it as a permanent installation to anyone. Thats my disclaimer. Anyway, on with some pics.
THIS IS AN EXPERIMENT and I'm not recommending it as a permanent installation to anyone. Thats my disclaimer. Anyway, on with some pics.
- Thread starter
- #166
After full warm up, and 15 minutes or so of driving, it sits at ~14.0VDC at idle and ~14.1 - 14.2VDC or so cruising at 2500 RPM. Much more like the voltage an AGM battery (or batteries in may case...) is designed to operate at.
This whole thing is only hours old at this point, and is PURELY experimental. I reserve the right to pull it out and go back to stock lol!
Keep in mind, my alternator is a high output J2 Fab Denso unit. While it provides higher amperage, it's designed around a lead acid battery, and the regulator is set to a more "normal" 13.5 or so VDC. This little trick bumps it up to keep my AGM batteries (all 4 of them) topped off and happy. Hopefully it doesn't let the magic smoke out of anything in the meantime.
This whole thing is only hours old at this point, and is PURELY experimental. I reserve the right to pull it out and go back to stock lol!
Keep in mind, my alternator is a high output J2 Fab Denso unit. While it provides higher amperage, it's designed around a lead acid battery, and the regulator is set to a more "normal" 13.5 or so VDC. This little trick bumps it up to keep my AGM batteries (all 4 of them) topped off and happy. Hopefully it doesn't let the magic smoke out of anything in the meantime.
I ran an Optima yellow top in a 1978 Ramcharger for ten years no mods no issues then sold the truck with that battery in it. I ran a Diehard platinum in two different 80’s for 8 years no mods no issues. Replaced that battery just to get a bigger group 31 X2 AGM and no issues there either.
What real world indications exist that tell us our vehicle needs mods to properly charge an AGM battery?
What real world indications exist that tell us our vehicle needs mods to properly charge an AGM battery?
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- Thread starter
- #168
I'll be honest- I don't know if there's real world indications. I too have had great luck with standard alternators and AGM batteries for the better part of 25 years.
Most AGM Manufacturers do specify they like to be charged to 14.2-14.5VDC, if you bother to read the fine print. I did this primarily as an experiment to see if it would work. I'll report any findings- good or bad as they happen.
I generally do keep my vehicles on a battery tender when parked- even those I drive frequently and I use the optima 400 charger on them in the appropriate battery setting. The optima charger runs them to 14.0-14.2 usually when I select once of the AGM modes rather than the regular lead acid mode, so maybe there's something to it. Who knows?
That’s the charge voltage, a proper AGM charger or battery management system switches to a lower “float voltage” once the battery is charged. If you give them 14.1V all the time you may over charge them. The lower voltage from a standard lead acid alternator will never fully charge them but it may be better than constant 14.1V for battery longevity.
All very interesting information as I run a AMG battery also.
Never any issues with stock charging system
But like @reklund5 I throw an Optima charger on there every once in a while.
Never any issues with stock charging system
But like @reklund5 I throw an Optima charger on there every once in a while.
COS80
SILVER Star
It seems to me that you both have the same, very slight issue I have with my AGM batteries and charging system - it's not cutting it, so you're charging the batteries with a charger. If the alternator was truly sufficient, we'd never need to tend or top them up.
I belive your problem is unique to your rig. Did you read post #167. Using a battery tender on a vehicle that doesn’t get driven daily is not a new thing, nor is it relegated to AGM’s, nor does this practice mean there is a problem to be overcome.
Four decades ago AGM technology was released to and used by the military on multitudes of equipment. Should we assume that those charging systems were specialized or that the military kept millions of pieces of equipment on a battery tender?
I wouldn’t say that’s totally true
My last AMG lasted 6 years without a single change from an outside source. It was still working fine when I replaced it And that was only because I travel/wheel in remote locations far off the beaten path.
I only have one battery a group 31 AMG odyssey.
I rely on it to run my 50 quart ARB refrigerator my winch and my onboard air and then it still has the duty to start the rig.
It’s not worth it for me to have it die when I need it most in the middle of nowhere.
Sometimes I camp in the Sierras for 2+ days, running in the fridge without moving or starting the rig, I have never had an issue.
It has always started wearing called upon.
I’m OCD like most here on mud so when I got a new battery, same odyssey I grabbed a charger as well, well because other mudder said it would help
It’s only money right
In closing I will add that I don’t DD my rig its a purpose built trail rig that can and does sit for weeks to months at a time.
COS80
SILVER Star
Yes, I think its very safe to assume that military equipment is "specialized" with alternators that produce the charging voltage specified by the battery mfrs.
- Thread starter
- #175
Gents-
I fully admit that this is a solution in search of a problem, and purely experimental.
While its widely accepted that AGM Batteries like a little higher charge voltage/float voltage than a conventional flooded lead-acid battery, there are millions of (old) cars on the road with AGM Batteries and 'standard' charging systems that run just fine. I have no data or evidence to prove that altering the alternators output will measurably change the life of an otherwise known good AGM battery. I will say, that many new cars have different charge profiles in them that can be selected via scan tool at the time of battery installation, specifically for different types of batteries. Many solar chargers have different profiles you can select based on battery type (Flooded lead acid, AGM, LiPo, etc) I don't think there's any harm in increasing the voltage a bit, but I also don't think there's any harm in running an AGM battery on a stock system.
My 1987 Supra has had an AGM battery on a totally stock charging system for years. My pickup in my avatar has run Optimas since 1998 when I bought it, and did so on the stock alternator until I installed a premier power welder in ~2015 or so. That PPW alternator does run at 14.2VDC pretty much all the time, and the battery is fine. I installed a new Optima in there in 2015, and took it out last year just because it was 10years old. It was FINE. It now lives in the back of my 80 as a 'house' battery.
My 80 has had dual X2 AGM batteries under the hood for a couple years now, on the stock alternator until last year when I did the engine swap, and installed a higher current alternator- that still kept them at 13.2 or so VDC when fully warmed up. Those batteries are just fine. Ive added 2 more optima yellow tops (both used, mind you) to the rear of the 80 as 'house' batteries in the last year and they're still trucking too.
The one thing I do to ALL my vehicles is keep them on trickle chargers ( l like the Optima 400 charger or the Ctek chargers over 'battery tender' brand, but thats just me) Keeping a battery topped up- no matter what type or how frequently you drive a vehicle- goes a long way to increasing the lifespan of the batteries in my option. The only exception to that is the lead acid batteries in my old F250. That truck has needed a new pair of batteries every 5 years like clockwork since I bought it. Doesn't matter what I do or how often I drive that damn old diesel.....
That was a really long way of saying (again) "who knows" There are so many variables with peoples vehicles- especially customized off-road trucks with a bunch of accessories- that its hard to quantify what is good or bad universally. I say run what works for you- and don't be afraid to experiment a bit and see if things can be improved incrementally.
I fully admit that this is a solution in search of a problem, and purely experimental.
While its widely accepted that AGM Batteries like a little higher charge voltage/float voltage than a conventional flooded lead-acid battery, there are millions of (old) cars on the road with AGM Batteries and 'standard' charging systems that run just fine. I have no data or evidence to prove that altering the alternators output will measurably change the life of an otherwise known good AGM battery. I will say, that many new cars have different charge profiles in them that can be selected via scan tool at the time of battery installation, specifically for different types of batteries. Many solar chargers have different profiles you can select based on battery type (Flooded lead acid, AGM, LiPo, etc) I don't think there's any harm in increasing the voltage a bit, but I also don't think there's any harm in running an AGM battery on a stock system.
My 1987 Supra has had an AGM battery on a totally stock charging system for years. My pickup in my avatar has run Optimas since 1998 when I bought it, and did so on the stock alternator until I installed a premier power welder in ~2015 or so. That PPW alternator does run at 14.2VDC pretty much all the time, and the battery is fine. I installed a new Optima in there in 2015, and took it out last year just because it was 10years old. It was FINE. It now lives in the back of my 80 as a 'house' battery.
My 80 has had dual X2 AGM batteries under the hood for a couple years now, on the stock alternator until last year when I did the engine swap, and installed a higher current alternator- that still kept them at 13.2 or so VDC when fully warmed up. Those batteries are just fine. Ive added 2 more optima yellow tops (both used, mind you) to the rear of the 80 as 'house' batteries in the last year and they're still trucking too.
The one thing I do to ALL my vehicles is keep them on trickle chargers ( l like the Optima 400 charger or the Ctek chargers over 'battery tender' brand, but thats just me) Keeping a battery topped up- no matter what type or how frequently you drive a vehicle- goes a long way to increasing the lifespan of the batteries in my option. The only exception to that is the lead acid batteries in my old F250. That truck has needed a new pair of batteries every 5 years like clockwork since I bought it. Doesn't matter what I do or how often I drive that damn old diesel.....
That was a really long way of saying (again) "who knows" There are so many variables with peoples vehicles- especially customized off-road trucks with a bunch of accessories- that its hard to quantify what is good or bad universally. I say run what works for you- and don't be afraid to experiment a bit and see if things can be improved incrementally.
COS80
SILVER Star
Agree 100%
Just something I learned while doing my LS swap.
OEMs have long moved to adaptive charging. No set voltage.
They measure current flow into/out of the battery, and then they adjust the alternator voltage as needed. They only provide enough voltage to meet the needs of the battery, no more or less.
For GM, the BCM tells the ECM, which adjusts a frequency pulse to the alternator, whenever it determines the battery needs to be charged.
The alternator then adjusts the voltage based on that incoming frequency pulse.
For my LS swap, and since I don't have a GM BCM measuring current flow, I just have the ECM tell the alternator to output 14.5V.
I also put my AGM on a smart battery tender. It has much more smarts (battery profiles) than a alternator outputting an set specific voltage.
OEMs have long moved to adaptive charging. No set voltage.
They measure current flow into/out of the battery, and then they adjust the alternator voltage as needed. They only provide enough voltage to meet the needs of the battery, no more or less.
For GM, the BCM tells the ECM, which adjusts a frequency pulse to the alternator, whenever it determines the battery needs to be charged.
The alternator then adjusts the voltage based on that incoming frequency pulse.
For my LS swap, and since I don't have a GM BCM measuring current flow, I just have the ECM tell the alternator to output 14.5V.
I also put my AGM on a smart battery tender. It has much more smarts (battery profiles) than a alternator outputting an set specific voltage.
COS80
SILVER Star
I recently noticed that my wife's car has an AGM battery, and I thought about taking some msmts to see how the factory did things, but then remembered I can't stand.
Your post (probably) answers the question anyway.
This^ well said
I like the KISS plan keep it simple stupid
Hence why I have one battery and a stock charging system
I like those side mouldings, is Leland selling those or was it somethign he had and didn't need. I am lookig to doa respray this year and would do those if my other idea doesn't work out.