Battery Maintainer

[Mighty Little Blue]

I recently (2 weeks ago) hooked up a battery maintainer, because the truck will sit for a few months. Right after I did that it went into sleep mode within a day or two. It has done that multiple times now even after a few long drives. After which I reconnected the charger.

Maybe a coincidence that it is happening now? Before using the charger it would sit 10 to 14 days before sleep mode. Battery is just a few months short of 5 years old. While driving scan gauge shows charging at 13 to 14v. Maintainer will show charging up to around 13v then shows full. Scan gauge reads 12.8v when charger is showing full. At the same time I started charging it the SOC was changed from 75 to 90% in Forscan.

Picture below shows where the positive is connected, and ground is on the frame. The other wire below charger wire is the lead for my auxiliary switches. Also included is a picture of the charger I am using, which was bought from Costco. It is good for all types of battery including AGM and has a maintenance function.

Am I doing something wrong?

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[got3fords]

Did you buy a maintainer or a drainer? Seriously though, it looks to me like you connected it to wrong side of the BMS sensor. Can't tell for sure.

 

[RangerBill]

I recently (2 weeks ago) hooked up a battery maintainer, because the truck will sit for a few months. Right after I did that it went into sleep mode within a day or two. It has done that multiple times now even after a few long drives. After which I reconnected the charger.

Maybe a coincidence that it is happening now? Before using the charger it would sit 10 to 14 days before sleep mode. Battery is just a few months short of 5 years old. While driving scan gauge shows charging at 13 to 14v. Maintainer will show charging up to around 13v then shows full. Scan gauge reads 12.8v when charger is showing full. At the same time I started charging it the SOC was changed from 75 to 90% in Forscan.

Picture below shows where the positive is connected, and ground is on the frame. The other wire below charger wire is the lead for my auxiliary switches. Also included is a picture of the charger I am using, which was bought from Costco. It is good for all types of battery including AGM and has a maintenance function.

Am I doing something wrong?

Have the battery tested. It may be bad. Also, try another charger. The voltages that you are reporting with the charger attached, sound too low.

 

[NotBudule2]

Almost 5 years on the battery plus your climate may be some of the issue , 5 years(or sooner) seems to be the number for a lot of these ...

 

[Mighty Little Blue]

“Did you buy a maintainer or a drainer? Seriously though, it looks to me like you connected it to wrong side of the BMS sensor. Can't tell for sure.”

Hopefully I got a maintainer and not a drainer.
BMS is on the negative side I am connected to ground on frame before the sensor.
Positive side is connected where Ford info shows to add accessory connections.

Battery is probably going bad and timing is just a coincidence.

Thanks for the info.

 

[Mighty Little Blue]

Have not tested battery, but put charger on another battery which was a lead acid. On this battery it charged to 14.4v before it said full so I think charger is good. Old battery is just going bad, 5yrs seems good for what has been mentioned on this site. I will see what it does when I get back in 8 months.

 

[TJC]

I have monitored and tested my battery since new. I purchased a 2020 XLT Ranger new. You really need a charger with a proven desulfator function to keep the battery in optimal condition. I have an onboard desulfator that only functions when the charger voltage is over 13v. It helps a great deal.

That said, I have a CTEK 8 stage 5amp charger. It took 3 weeks of continuous charging for that charger to reach stage 8. It went to stage 7 within 6 hours. During that 3 weeks, my onboard was constantly active, breaking down sulfur crystals that build up on the lead plates. This buildup increases the internal resistance (IR) of the battery causing increased voltage to charge the battery, and weakens the batteries ability to hold a charge. Optimal is in the 3.5 mOhm range. Above 5 mOhm and your battery has been weakened and is at risk. Above 8 and it is time to replace the battery. The low SOC Ford sets and active ASS will kill the battery prematurely. Engineers estimate active ASS systems shortens battery life by 2 years.

My battery is 6 years old now and still healthy. But it takes effort to keep a battery healthy in modern power hungry autos. I charge my battery usually once a month. I have ASS disabled, have an onboard desulfator, and set SOC to 95%. I suspect 85%-90% is probably optimal, but that is still being tested by several of us on this forum. Ford's charging system (BMS) is quite sophisticated and is tuned for EPA mileage advantage, not battery life. IMO, the ever so slight mileage improvement ( <0.1 mpg ) doesn't make up for premature battery failure. I am targeting a 10 year battery life. I have gotten that on all my previous autos, but none of them had the massive amount of electronics in them. I'm on my 3rd battery in my 2005 Ranger... going on 22 years of ownership. When my batteries do fail it has been a shorted cell.

My 2020 Ranger forced me to reevaluate and update my battery care strategy.

 

[2021Ranger]

Question how do you check the mOhm?

 

[fob63]

Are these any good as a disulfate unit?
It shows to be connected all the time. I would think that would drain the battery.

 

[TJC]

Question how do you check the mOhm?

With a Battery Tester.
I own several different brands, those in the red boxes were most accurate. The Ancel in green was accurate and inexpensive.

See the full test video here

 

[dtech]

Are these any good as a disulfate unit?
It shows to be connected all the time. I would think that would drain the battery.

I have one of those and yes as their documentation explains it will drain your battery if left connected for an extended time. I would recommend buying a battery charger with a desulfation mode and using that periodically instead or a more expensive onboard desulfation device like tjc uses that isn't continually on. And lower end chargers with desulfation mode are only effective for batteries that are not heavily sulfated so it's important to not allow that to happen to a battery as only more costly desulfation devices are effective for heavy sulfation and even then the battery may be beyond recovering.

 

[TJC]

You need to start a desulfation regimen when you install a new battery, esp in vehicles like our Ford Ranger which keep the battery in so low a charge that sulfation is constant. Once the sulfur crystals reach a density threshold it is extremely difficult to break them up. Monitoring the Internal resistance is the easiest way to monitor the buildup. Target <=3.5 milliOhms. If you see 4 milliOhms you need to immediately act. By 5 milliohms your battery is weakened and on the way out. The crystals will have grown too large and It will be difficult to break them down. It can be done, but it is going to take a lot of time - many months, not weeks. By 10 it is game over.

Ford's algo for determining SOC appears to drift downward, which becomes a problem over time, as it lowers the voltage charge target. Once that target drops below the 12.65v - 12.7v range sulfation begins to occur. The lower the voltage, the faster the sulfur crystals form, the higher the internal resoistancebeomes, and the faster the voltage drops. Additionally the higher the Internal resistance (IR), the higher the charging voltage needed to recharge the battery, and the quicker the battery will discharge under load.

We are up against a 2 edged sword. The sensitive electronic systems required to manage engine and transmission functions need a very stable power source to perform normally, and Ford designed a BMS which compromises battery life (and engine and transmission stability) over very slight EPA gains.

A weak battery can and does affect engine performance and transmission shift patterns. Everything is now all computer controlled. When the computer goes bipolar from low or unstable power, it can and will instruct your engine and transmission to do stupid things..... It really is a ripple effect.

In the early 1990's I installed an aftermarket ECU in my 1993 Supercharged Miata. I installed the SC and made 175hp at the wheels from a 95 hp 1.6 4 cylinder, but I needed to monitor fuel and timing curve to keep knock under control. Upon initial testing I set the fuel and timing tables, and then drove the car to allow the computer to adjust to the target fuel/air ratio and timing.

It worked fine until I would turn on the headlights or the turn signals, then the computer would start to enrich the fuel / air mix! It took me months to chase down the issue. It was poor grounds! I had to rout all grounds on the car to the engine or negative battery terminal. When I did, all the bugs disappeared. That very slight difference in resistance caused enormous problems.

Something very similar and possibly worse happens with our Rangers when the battery can't hold a sufficient charge. Gremlins start to appear, and they get worse as the voltage fluctuates as the battery weakens.

The bottom line is battery health is more important then ever.

 

[got3fords]

“Did you buy a maintainer or a drainer? Seriously though, it looks to me like you connected it to wrong side of the BMS sensor. Can't tell for sure.”

Hopefully I got a maintainer and not a drainer.
BMS is on the negative side I am connected to ground on frame before the sensor.
Positive side is connected where Ford info shows to add accessory connections.

Battery is probably going bad and timing is just a coincidence.

Thanks for the info.

Oh, right, negative side. It sounds like a strange coincidence then that your issues started when you hooked up the maintainer.

 

[got3fords]

I have one of those and yes as their documentation explains it will drain your battery if left connected for an extended time. I would recommend buying a battery charger with a desulfation mode and using that periodically instead or a more expensive onboard desulfation device like tjc uses that isn't continually on. And lower end chargers with desulfation mode are only effective for batteries that are not heavily sulfated so it's important to not allow that to happen to a battery as only more costly desulfation devices are effective for heavy sulfation and even then the battery may be beyond recovering.

I have been using an onboard desulfator for about 3 years now. It resides right near the battery, and is only active when the charge voltage exceeds 13.5V. I am on my original battery, purchased the truck in April of 2021. No battery symptoms yet.
Weird thing is, I can't find the specific model on Amazon any more.

 

[2021Ranger]

Tony, so what are you using for an on board desulfator.

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