trailer battery connection

Sep 05, 2003 5 Replies
B

I have a trailer with an internal battery to run lights, a winch, the trailer emergency brake, that sort of thing. My previous tow vehicle had a charging lead so that the trailer battery was charged by the vehicle while it was being towed. The current tow vehicle doesn't have this lead connected, so I charge the battery while stopped with a normal battery charger.



I would like to connect up a charging lead, but I wonder if it should be connected directly to the vehicle battery, or to a switched source? My last truck seemed to have it direct, since I could run the trailer lights by plugging into the truck, which would be handy.



Any ideas on how this is normally wired would be appreciated.



Cheers, Brian


Vote
Twitter Facebook LinkedIn
G

Ok, ASCII art schematic follows, switch to a fixed pitch font now.

diode 1 x---->|-------BAT 1-------Loads | Alternator+ ----x | x---->|-------BAT 2-------Loads diode 2

Gary

Vote
Twitter Facebook LinkedIn
A

Hmmm, that only seems to involve one power rail, and puts the load in series with the battery... you sure about that?

I'd say that it would be more like running several diode bridges off of the alternator rails, then having the output of the bridge in parallel with battery and load.

AC1 and AC2 are connections to the alternator:

AC1 --------+----->|------+-----------------------\ | | | | | | - - | ^ ^ | | | | | | | +------>|-----+--------- AC2 | | | | | +--------------| |--------------------+

Vote
Twitter Facebook LinkedIn
L

On Sat, 06 Sep 2003 13:15:31 +0100, Alaric B Snell pixelated:

- - |_______________ground_________________________|

He just left off the ground circuit since it was easily inferred.

Imagine the ground dropping down from the Alternator- and running over to the right side of the load, the load-. (see my mods above)

Yes, a hot leads goes in series through the load to ground.

A smoothing cap isn't necessary since it's performed (to a great extent) by the solid-state regulator and batteries are VERY forgiving.

------------------------------ Gator: The other white meat! ------------------------------

formatting link
Comprehensive Website Development

Vote
Twitter Facebook LinkedIn
G

The output of an auto alternator is DC (the rectifiers are internal). The loads, and the alternator negative in my diagram are, as is normal in automotive practice, returned via the chassis. I didn't bother to sketch that in since ASCII art is difficult enough without all that extra detail.

Gary

Vote
Twitter Facebook LinkedIn
C

On mine I have an isolator solenoid that connects the battery of the vehicle to the charge line.

Vote
Twitter Facebook LinkedIn

Join the Discussion

Have something to add? Share your thoughts — no account required.

Didn't find your answer?

Ask the community — no account required