How To Install a Battery On a Trailer for Use with Electric Jack

Updated 06/02/2025 | Published 10/02/2019

Products Featured in This Question

Snap-Top Battery Box with Strap for Group 24 to Group 31 Batteries - Vented

(258)

$35.20

10 Gauge Wire - Blue Primary - Per Foot

(102)

$1.91

Question:

I purchased one of your electric jacks. I want to add a battery and battery box to my enclosed trailer to run jack but how can I wire it up to keep battery charged? I want to vehicle to be able to keep a charge in battery so I don't have to manually charge battery. How big a battery do I need ?

asked by: Ronnie

Expert Reply:

I have attached a photo for you that shows how a 7-way trailer connector is wired. If you take a look at the trailer side trailer connector you will see a terminal labeled "12V Power". If you were to run a wire part # 10-1-1 (per foot) from this terminal on the 7-way trailer connector to the positive terminal on the battery that would then provide a maintenance charge while the trailer is attached and the vehicle is running or the key is in the ACC position. This will depend on how the vehicle is wired. The trailer jack can then be attached directly to the trailer battery.

In order to mount the trailer battery up on the tongue near the electric jack you can use the NOCO Snap-Top Battery Box with Strap part # 329-HM318BKS. I don't have a specific battery recommendation for you but any 12 volt deep cycle marine battery should do the job.

expert reply by: Conner L

click to enlarge

Dan

2/23/2024

Does it have to be grounded to

Jerred H.

2/24/2024

@Dan Yes, it does!

Marshall

6/1/2025

Ronnie, Understood your answer to this question, I’m in the same situation. My question is whether or not this could potentially drain my truck battery when vehicle is not running but trailer is still plugged in. I have a ‘21 F150. Thanks in advance for the response. Marshall

Jerred H.

6/2/2025

@Marshall Yes, it will drain a truck battery eventually. How long it takes will depend on many variables. Age of battery/s, temp, how often you're using things connected to the trailer battery.