Battery minder/charger question

[RazzaRossa]

I've had a small Battery Tender for years, love it. I bought a 12ft extension for it. The plug ends have water tight covers. I even accidentally ran it over with my truck, thought it was destroyed, hammered it straight (metal housing) as best I could, and it keeps on tickin'.

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[Bitten in '69]

My preferences are Deltran's Battery Tender, or the models by CTEK.
CTEK also makes an adapter that connects to Deltran pigtails.
One disadvantage of the Deltan is that they will not turn on and charge a battery if it is below a specific voltage. The CTEKS will charge from zero.

 

[luc]

I did not realize a lead acid battery would even have a BMS. I’ve got a lithium battery for my bass boat and it has one built into the battery itself. Are you referring to a BMS on the vehicle itself?

I’m confused because the Battery Tender support staff never mentioned doing this and he knew it was a 2023 Ford Mustang as he asked me.

Mustang, ford in general and a bunch of other vehicles have used bms for quite some time
Just google ford bms
Yes, the seller should have known better

 

[ORRadtech]

I did not realize a lead acid battery would even have a BMS. I’ve got a lithium battery for my bass boat and it has one built into the battery itself. Are you referring to a BMS on the vehicle itself?

I’m confused because the Battery Tender support staff never mentioned doing this and he knew it was a 2023 Ford Mustang as he asked me.

The BMS is part of the cars charging system, not built into the battery. Ford has done this (BMS) since at least 2012. They're more sophisticated now though.
For a long time I connected directly to the battery but I have since come to understand that bypassing the BMS can have adverse effects on battery condition.
This might help you.

 

[I Bleed Ford Blue]

I have mine hooked directly to the battery and never had an issue. Did it that way for 6 years on my 17, and it the same setup on my 23.

The way I see it, the car is off and being stored, who cares what the BMS thinks. I've had mine setup like this for 8 winters now and never had an issue.

 

[Garfy]

@Ford Blue I've had mine connected the same way as yours and haven't had an issue either. Seems to me that whether the system voltage is at the battery or the fuse/relay box, it's still the same. My BMS still shows the correct age of the battery and I'm still running the original battery in the car and thankfully it doesn't seep acid like so many other batteries I've seen where the cables and posts have serious corrosion build-up on them. I remove the cover periodically to be sure there is no corrosion beginning or electrolyte leakage from the battery. My car isn't a daily either especially since winter snow and salting the highways began (not to mention that the summer tires are horrible for traction when it's below 40).

 

[Stang4me]

I need to buy a battery minder/charger for my Mustang GT. Stupid cold weather and salt/snow is not allowing me to drive it as much as I’d like so my battery is getting weak in between starts.

I would like a battery minder/charger that comes with a quick-connect/disconnect set of O-ring adaptors that allow me to keep the two wires connected to the battery but allow me to easily/quickly disconnect it when I go to drive the car.
I’m partial to NOCO and Battery Tender brands but their websites do not indicate which of their devices have a quick-connector for the battery leads. Anyone know?

I have two of these for my mustangs. They are not the cheapest but one of the best reviewed I believe. They worked well through the winter here in Canadaeh.

 

[Grimmer]

@Ford Blue I've had mine connected the same way as yours and haven't had an issue either. Seems to me that whether the system voltage is at the battery or the fuse/relay box, it's still the same.

The vehicle's power in / power out sensor that the BMS uses to monitor usage/replenishment for managing charging is in-line between the positive battery post and the fuse / relay box. The owners manual advises to not charge directly at the battery post because the BMS would be unaware of the power being added back into the battery and would consequently call for more charging than is necessary.

For long term storage I don't think it would matter because the BMS can also reset its understanding of the battery's charge state based on standing voltage when not being used for 8hrs or so.

 

[Bman5150]

Just reviewed my Owners manual and found the following:

“After battery replacement, or in some cases after charging the battery with an external charger, the battery management system requires eight hours of vehicle sleep time to relearn the battery state of charge. During this time, your vehicle must remain fully locked with the ignition switched off.”

and…

“Electrical Accessory Installation:
To make sure the battery management system works correctly, do not connect an electrical device ground connection directly to the battery negative post. This can cause inaccurate measurements of the battery condition and potential incorrect system operation.”

Presumably, an electrical accessory would be a battery maintainer. But at the same time, it seems Ford also engineered a failsafe strategy if you just put a charger on the car. Maybe that’s why many don’t seem to have an issue with connecting straight to the battery?

 

[Bman5150]

Great info-thanks for sharing. I used to work on my cars myself all the time including on my 2001 GT but things have continued to become more complex. Appreciate all this info. Thx

 

[murick]

Since I had to face the similar situation yesterday and found this thread to be quite inspirational, I would like to add few more observations.

To the caveats already mentioned by @Bman5150 there is one other interesting detail in the owner's manual:

Remove and Reinstall the Battery
To disconnect or remove the battery, do the following:
1. Apply the parking brake and switch the ignition off.
2. Switch all electrical equipment off, for example lights and radio.
3. Wait a minimum of two minutes before disconnecting the battery. (emphasis mine)
Note:The engine management system has a power hold function and remains powered for a period of time after you switch the ignition off. This is to allow diagnostic and adaptive tables to be stored. Disconnecting the battery without waiting can cause damage not covered by the vehicle Warranty.
4. Disconnect the negative battery cable terminal.
5. Disconnect the positive battery cable terminal.
6. Remove the battery securing clamp.
7. Remove the battery.
8. To install, reverse the removal procedure.

I had to remove the battery from the car for the charging, so did not have to connect the charger to the car, but the from the electrical point of view, you should be fine with connecting the positive cable to the battery and negative cable to the chassis. This should ensure that the BMS stays in the loop for the charging process.

In my case the battery was able to unlock the car with the remote, power on the dashboard but did not have enough juice to run the starter and eventually died. When removed from the car the measured voltage was 11.33 V. Which is pretty low, according to the internet wisdom and the battery should be dead.

I was able to charge it though and even run "reconditioning" on the battery, using a charger option. Now I am just wondering if the battery will hold the charge. Technically the charger also run a test for that, which passed, so I will see.

FWIW since I charged the battery in home on a measured plug, for the interested here, following is a charging recorded in input wattage (the 10 W consumption visible before and after the charge is related to some other device).

The charger I used was EU version of this https://www.ctek.com/us/battery-chargers-12v-24v/mxs-5-0-na and the description used in the above graph matches the charger vocabulary.

 

[Bman5150]

I’ll add that I did end up using a battery tender hooked up the correct way and it worked great. No issues. I would also emphasize to disconnect the battery before installing the charger harness. Too easy to possibly drop something and cause a short or damage across exposed electrical connections.

 

[young at heart]

I’ll add that I did end up using a battery tender hooked up the correct way and it worked great. No issues. I would also emphasize to disconnect the battery before installing the charger harness. Too easy to possibly drop something and cause a short or damage across exposed electrical connections.

By “correct“ way do you mean the old fashioned way directly to the battery posts per Deltran’s support?

 

[Oakley]

i used a agm battery tender brand one for my cobra.

 

[Bman5150]

Hooked up correctly = according to my vehicle’s owners manual authored by the manufacture of said vehicle.

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