Negative Ground Point for CTEK Battery Charger

[GScottS]

Where is a good negative ground point for connecting a CTEK battery charger? Everything inside the engine bay is painted or covered with plastic. Don't want to mess up the BMS...

Background. Started getting the "System Off to Save Battery" message on display when opening door after truck has sat overnight. AS/S not working, sensor chimes playing through dash speaker rather than stereo (which is turned off), etc. I drive every day, but usually only 15-20 miles. So took a 50 mile drive to see if battery would return to normal operation. System off message still occurng.

Tested battery resting state with a multimeter 2 mornings in a row - 11.9 and 12.2. Assumed this was clearly a bad battery and called Ford Service to have tested and replaced under warranty. Need to wait 3 weeks for appointment!

I would just buy a replacement battery myself but want to be certain there is not a parasitic draw or some other problem causing the battery drain so am keeping the appointment. In the meantime I bought a CTEK Charger to (hopefully) get the battery to charge.

Recommendations on a good ground location appreciated as well as others experience with resolving this issue. Thanks!

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[AzScorpion]

I grounded mine to the side of the fender. I'll dig up the picture and post it.

 

[Trigganometry]

Anyplace you can find some bare metal under an existing fastener. Use some dielectric grease before fasting the connector to keep oxidation at bay. That will keep the connection points trouble free for as long as you own the truck!

 

[AzScorpion]

Anyplace you can find some bare metal under an existing fastener. Use some dielectric grease before fasting the connector to keep oxidation at bay. That will keep the connection points trouble free for as long as you own the truck!

Or you can do what I did and let the dirt seal it up good.

 

[JesseS]

There are a few grounding straps in the engine bay, I grounded my tow battery charger to the top post on the negative terminal on the battery, not the battery post itself but the BMS connection, that way the BMS will still read the power flow.

 

[GScottS]

I grounded mine to the side of the fender. I'll dig up the picture and post it.

Do you have your charger permanently attached? I was just planning to use the alligator clips, at least initially...

 

[Msfitoy]

I grounded mine to the side of the fender. I'll dig up the picture and post it.

I love your meticulous engine bay...needs more Graphine... ?

 

[GScottS]

There are a few grounding straps in the engine bay, I grounded my tow battery charger to the top post on the negative terminal on the battery, not the battery post itself but the BMS connection, that way the BMS will still read the power flow.

Thanks, I had not considered that. Just to clarify location - here?

 

[Msfitoy]

Where is a good negative ground point for connecting a CTEK battery charger? Everything inside the engine bay is painted or covered with plastic. Don't want to mess up the BMS...

Background. Started getting the "System Off to Save Battery" message on display when opening door after truck has sat overnight. AS/S not working, sensor chimes playing through dash speaker rather than stereo (which is turned off), etc. I drive every day, but usually only 15-20 miles. So took a 50 mile drive to see if battery would return to normal operation. System off message still occurng.

Tested battery resting state with a multimeter 2 mornings in a row - 11.9 and 12.2. Assumed this was clearly a bad battery and called Ford Service to have tested and replaced under warranty. Need to wait 3 weeks for appointment!

I would just buy a replacement battery myself but want to be certain there is not a parasitic draw or some other problem causing the battery drain so am keeping the appointment. In the meantime I bought a CTEK Charger to (hopefully) get the battery to charge.

Recommendations on a good ground location appreciated as well as others experience with resolving this issue. Thanks!

If you need a ground on passenger side, look down at the area between the headlamp and the filter box...there's a factory ground wire 10mm bolt head...

 

[AzScorpion]

Do you have your charger permanently attached? I was just planning to use the alligator clips, at least initially...

No I added the extension cable and routed it so it comes out by my tow hook. There's a rubber boot there so I can tuck it up in there when not in use. Now I can just quick connect it without opening the hood.

https://www.amazon.com/gp/product/B00ADIHUVG/ref=ppx_yo_dt_b_asin_title_o08_s00?ie=UTF8&psc=1

 

[JesseS]

Thanks, I had not considered that. Just to clarify location - here?

That's the spot.

 

[AzScorpion]

I love your meticulous engine bay...needs more Graphine... ?

I spend so much time detailing the interior and exterior I'm to tired to do the engine bay. ?

 

[Msfitoy]

I connected my charge lead directly to the positive and negative posts...it's terminated with a switched volt meter or disconnects for connecting to maintenance charger...

 

[JesseS]

I wasn't sure of what the load draw limit of the BMS sensor was so only ran the neg charger lead to it, with all other loads grounded to the frame. There are 10mm grounding points on both side corners.

Remote switch grounded to frame

Towed Battery charger grounded to BMS

And yes I keep my engine bay clean, makes it easier (and nicer) to work on.

 

[GScottS]

No I added the extension cable and routed it so it comes out by my tow hook. There's a rubber boot there so I can tuck it up in there when not in use. Now I can just quick connect it without opening the hood.

https://www.amazon.com/gp/product/B00ADIHUVG/ref=ppx_yo_dt_b_asin_title_o08_s00?ie=UTF8&psc=1

Thank you! Definitely going to do this for long term ease of use

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