Trailer Battery Not Charging Message
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Laughing Gas
Joined: Apr 2003
Posts: 795
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23 F250 CCLB PS HO
Edited SIG
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Laughing Gas
Joined: Apr 2003
Posts: 795
Likes: 232
I don't think I'm doing anything different. I always select the correct trailer when towing (as saved brake settings are significantly different).
The one trailer (that I tow heavier with) has a newer grp 65, 1000 amper in it, as it was converted to E/H and I didn't want to draw those amps from pump, directly through trailer connector (exclusively, anyway).
The other has an older (whatever small batt they normally stick in newer trailers these days). It charges up a on trickle no problem, holds charge fine and works
the brakes and lights without trailer connected to any other source ( I have not load tested it yet though). I have a couple light weight batt's, used in some of my perf cars, that would be a significant upgrade
over that "trailer batt" . Just need to find a small "batt box" for one of them.
Anyway, will look up "procedure", but I don't think that is my issue (or at least it wasn't, the first 6 times I towed).
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Laughing Gas
Joined: Apr 2003
Posts: 795
Likes: 232
So right in the manual. Batt is probably "too old", whatever that means.
"If the vehicle’s battery voltage is in
optimum condition, above 12.5 volts,
and the trailer’s battery can still hold a
charge, or is not too old."
"If the vehicle’s battery voltage is in
optimum condition, above 12.5 volts,
and the trailer’s battery can still hold a
charge, or is not too old."
Fleet Mechanic
Joined: Dec 2016
Posts: 1,824
Likes: 545
From: Florida
I installed a DC-DC charger and occasionally get that message too at startup. I think it just takes a few seconds for the charger to fire up.
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Laughing Gas
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Cross-Country
Joined: Jul 2006
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Trailer breakaway batteries are little 12v SLA. They last 4-5 years if you use trailers every week, or keep them on a charger. About 2-3 years if you don't. Pull the battery out, match the amp hours on it and order one from Amazon or stop by your local batteries plus franchise. They are less than $25.
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Laughing Gas
Joined: Apr 2003
Posts: 795
Likes: 232
Trailer breakaway batteries are little 12v SLA. They last 4-5 years if you use trailers every week, or keep them on a charger. About 2-3 years if you don't. Pull the battery out, match the amp hours on it and order one from Amazon or stop by your local batteries plus franchise. They are less than $25.
(I would have load tested it, but it had no "traditional" rating on battery case). Did not think there was anything wrong with old one,
but I now I know there wasn't.
More Turbo
Joined: Aug 2005
Posts: 689
Likes: 216
According to Ford the message means: Trailer Battery Not Charging See Manual = The trailer battery voltage is too low to charge.
Sooooo..... maybe time to check your trailer wiring starting with your cord. Maybe swab out your truck connector too. Especially if you get that message with a new, good battery.
Sooooo..... maybe time to check your trailer wiring starting with your cord. Maybe swab out your truck connector too. Especially if you get that message with a new, good battery.
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Laughing Gas
Joined: Apr 2003
Posts: 795
Likes: 232
According to Ford the message means: Trailer Battery Not Charging See Manual = The trailer battery voltage is too low to charge.
Sooooo..... maybe time to check your trailer wiring starting with your cord. Maybe swab out your truck connector too. Especially if you get that message with a new, good battery.
Sooooo..... maybe time to check your trailer wiring starting with your cord. Maybe swab out your truck connector too. Especially if you get that message with a new, good battery.
I have this small "onboard" module (inside battery box, came "stock" with trailer), appears to be a tiny battery charger
Seems to be isolating battery voltage from truck, which I guess was a good thing on an older truck, that did not regulate charging trailer batt?
I am upgrading battery on trailer anyway, to a small AGM I had as a lightweight batt on my 14 Stang (now sold, got newer GT500), as I installed
5K electric trailer jack.. But I assume I don't need that module any longer, just let truck regulate battery charging on it's own (if/when)?
All my trailers (heck every vehicle I own, except DD) get tenders when not in use (and not connected), so truck should sense a fully charged batt
when first connected.
Hotshot
Joined: Oct 2015
Posts: 19,734
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From: Wyoming
When the topic of a DC-DC charger came up I was going to say that those devices are typically a one-way circuit. The truck may not know what's going on with the trailer due to a lack of feedback from the DC-DC charger.
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Laughing Gas
Joined: Apr 2003
Posts: 795
Likes: 232
So that little trailer onboard charger was calling for zero draw. Looks like truck was only seeing 3V @ that point, making truck think trailer bat was dead.
Have to love TECH sometimes, "smart" tech being fooled by lower tech..........
Logistics Pro
Joined: Sep 2002
Posts: 4,414
Likes: 1,018
From: Central KY
I've had multiple trucks from every major brand in the U.S. and Ford is the only company that seems to have trouble designing a reliable trailer wiring system. It's madness. Why is this so difficult for them?