Best Way to hook up a battery tender?

[mgr1001]

I'm sure subject has been covered ad nauseam in these forums, but I need to ask again about the best way to connect a battery tender to my 2024 hybrid. The problem is there's so much information, some of it conflicting, I don't know who to listen to.

At first glance, it appears that there are two ways to connect a battery tender. One is directly to the battery terminals under the rear seat, and the second is to jumper posts under the hood.

My question, is there any functional difference between the two?

For several reasons, I would prefer to use the under hood terminals. Mainly, this will allow for a much easier connection process when the truck is in the garage.

Thoughts please?

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[matmondro]

There is no functional difference between them. The ones under the hood are just more convenient to access.

 

[SafetyGuy]

I'm sure subject has been covered ad nauseam in these forums, but I need to ask again about the best way to connect a battery tender to my 2024 hybrid. The problem is there's so much information, some of it conflicting, I don't know who to listen to.

At first glance, it appears that there are two ways to connect a battery tender. One is directly to the battery terminals under the rear seat, and the second is to jumper posts under the hood.

My question, is there any functional difference between the two?

For several reasons, I would prefer to use the under hood terminals. Mainly, this will allow for a much easier connection process when the truck is in the garage.

Thoughts please?

I completely agree with the previous post, I also feel there is no difference for you to use for your smart charger. Under the hood is my go to connection point, every time.

I have metered the 12 volt battery voltage at both points (directly at the battery as well as at the connection points under the hood, and I found there is no difference in the metered value.

Explanation why I metered both, and did it one right after the other.

There's no drop in the metered value, so a sufficiently large diameter cable connects the boost points to the battery has been utilized.

This is great, as there is no line voltage drop (between the two points), due to an insufficiently sized wire.

Cheers

Andy

 

[sajohnson]

Not sure about the Maverick, but with the BS there is a current sensor on the neg(-) battery post. In order for the system to keep track of the state of charge (SOC) all current into and out of the battery must flow through that current sensor.

 

[Glen Baker LLC]

Michael, @mgr1001

I have it connected directly to the battery. I leave the charger in the truck hooked up 24/7
No diy cutting, no added resistance
That's Best and Convenient for me, because
Nobody has provided any proof that it's detrimental to the system. (I'm sure someone tried looking, but came up empty with actual facts.)
And if you're talking about a little mini amp charger. I want a little resistance as I can get.
This is how I have mine hooked up.
2 years and I haven't had a problem. Only had to use it twice.
I still have the original flooded 2023 motorcraft battery.

The charger stays in the truck hooked up easy peasy. So

 

[RideSolo]

I have tenders hooked up to both my '24 Hybrid Maverick and my '20 Hybrid Escape. Both are hooked up to the under the hood jump points and have always worked perfectly. I use tenders from Harbor Freight and they have relatively short 120vac power cords do I have the tender mounted up near the fire wall and the cord routed up through the rubber drain by the windshield wipers. When we leave town to go south for the winter the Escape stays plugged in the entire time. This hookup has always worked perfectly w/ no problems with either vehicle.

 

[Aleks]

I did it under the hood on the jump posts on my '25 hybrid awd.

I got these

https://amzn.to/4vo7VZT

and extended the wiring to the passenger side since the way I park in the garage there's no outlet on the drivers side.

I got this idea from another forum member on here and mounted it on the fender side trim below the lariat badge.

 

[sajohnson]

From Google:


Yes, the 12-volt chassis battery in the Ford Maverick does have a current sensor. It is known as the Battery Monitoring Sensor (BMS). [1, 2, 3]
Here is what you need to know about it:

• Location: The sensor is clamped directly onto the negative battery terminal. [1, 2]
• Function: It measures the current (amperage), voltage, and temperature of the battery to help the vehicle regulate the alternator's output and monitor the battery's overall state of charge. [1, 2]
• Maintenance Warning: If you are ever charging the battery or connecting a trickle charger, you must connect the negative/ground clamp to an unpainted chassis ground point (or a designated jump post) behind the sensor. If you connect the charger directly to the negative battery post, you bypass the sensor, and the vehicle's computer won't know the battery is being charged. [1, 2, 3]
• Replacement: If you ever replace the battery, you need to perform a BMS reset so the computer relearns the new battery's charge status. [1, 2]

###

 

[Glen Baker LLC]

From Google:


Yes, the 12-volt chassis battery in the Ford Maverick does have a current sensor. It is known as the Battery Monitoring Sensor (BMS). [1, 2, 3]
Here is what you need to know about it:

• Location: The sensor is clamped directly onto the negative battery terminal. [1, 2]
• Function: It measures the current (amperage), voltage, and temperature of the battery to help the vehicle regulate the alternator's output and monitor the battery's overall state of charge. [1, 2]
• Maintenance Warning: If you are ever charging the battery or connecting a trickle charger, you must connect the negative/ground clamp to an unpainted chassis ground point (or a designated jump post) behind the sensor. If you connect the charger directly to the negative battery post, you bypass the sensor, and the vehicle's computer won't know the battery is being charged. [1, 2, 3]
• Replacement: If you ever replace the battery, you need to perform a BMS reset so the computer relearns the new battery's charge status. [1, 2]

###

Is anything detrimental that is supposed to happen?
It's been 2 years trouble free.

 

[sajohnson]

Is anything detrimental supposed to happen? It's been 2 years trouble free.

I'm afraid your Maverick is toast -- scrap value.

AFAIK, the only issue is that the BMS will think the battery has less of a charge than it does.

 

[Glen Baker LLC]

I'm afraid your Maverick is toast -- scrap value.

AFAIK, the only issue is that the BMS will think the battery has less of a charge than it does.

If that's the case, shouldn't the battery have died?
After each of the two times I charged the battery. I did the BMS 8 hour relearn.

 

[Glen Baker LLC]

Just now I went out to my truck with a voltmeter. I opened the door and with all the standard interior lights and bed lights, tail lights, parking lights on. This was the reading on the voltmeter from my ORIGINAL 2023 flooded battery.
Sorry about the shadow. It's my phone. I was shining a light.

 

[sajohnson]

If that's the case, shouldn't the battery have died?
After each of the two times I charged the battery. I did the BMS 8 hour relearn.

If a charger is being used, the battery will be charged to 100% SOC (given enough time) but the BOC will not realize it.

However, since you are doing the relearn procedure it should be fine.

 

[sajohnson]

Just now I went out to my truck with a voltmeter. I opened the door and with all the standard interior lights and bed lights, tail lights, parking lights, on this was the reading on the voltmeter from my ORIGINAL flooded battery. The shadow you see is my phone I had a headlight on.

That's about what I see with our BS -- with both the OE FLA battery and the replacement AGM.

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