Does a Reefer trailer help power the truck battery's while truck is off?

I have started trucks several times using jumper cables run to the reefer battery...It will charge but not a ton of amps....

 

First thing to learn is cleaning the screen in the fuel line...and how to prime it back up.
Usually a banjo style bolt you remove to get access to the screen.

I learned that on my own on the side of I-95 one 95 degree day....Not fun but got it running and on my way..
Thermo King units are known to plug up when they get older and trash in the fuel tank.

 

As others have said, the short answer is NO. However, there are some kits you can buy to use the refer unit as part of a APU set up that will recharge the batteries of an "electric APU" system.
http://idlefreesystems.com/no-idle-elimination-solutions-for-reefers-and-refrigerated-trailers.html

That could be what you have heard people talking about.

 

Remember , when you're at the feeding holes don't step in the "male bovine feces"

 

If you wanted to use the reefer to keep the batteries charged so you could watch your scat porn or whatever you're into for 34 hours straight while you reset your 70, I'd recommend you run your ground to the earth if you don't have the jumper posts set up on the back of your power unit as described above... with the propensity for current truck designs to use multiplexed systems with lots of chassis-mounted electronics, grounding to the frame for a jump start or charge is highly discouraged.

 

Actually yes it can if it is setup right. If you own or are buying one, then you can have it setup to power your sleeper or charge your batteries. But company reefers, forget that idea.

I think both TK and Carrier have kits that you can get that will do this, Carrier did install something on my reefer unit so I could charge the batteries.

 

It can if you connect jumper cables from the reefer battery to the truck. I know because Ive done it when my truck's alternator died and I was 30 miles from a terminal so decided to let the reefer's alternator charge my batteries to give me enough juice to make it to my terminal and that worked. The reefer's alternator puts out 14 volts and anything over the capacity of the battery's current voltage output will charge it. Amperage determines how fast it will charge. I am glad I got that mobile electronics certification when I was a teenager its helped me a lot.

 

It works like the moon charging the batteries in your tv remote....

 

i have it on the truck I'm in now. Works like a champ. No issues. Only thing you have to remember is to disconnect it before you start driving after your break.