Using coach to start a car

Topic: Using coach to start a car (Read 803 times) previous topic - next topic

Using coach to start a car

November 04, 2019, 07:10:32 am

Good morning,
Just got back from my trip and my car is dead.
Can I jump it with my coach batteries?
Thanks Frank

Re: Using coach to start a car

Reply #1 – November 04, 2019, 07:29:25 am

Sure, why not? Hook the jumper cables to whatever battery is easiest to get to. Doesn't matter how "big" the start battery is - car starter will only draw the amps it needs to spin the engine.

Re: Using coach to start a car

Reply #2 – November 04, 2019, 07:59:43 am

Hi Chuck it doesn't matter how the batteries are connected whether in series or parallel

Re: Using coach to start a car

Reply #3 – November 04, 2019, 08:09:50 am

Just attach the jumper cables to the POS and NEG post on one of your batteries. I think it won't matter if that battery is connected to other batteries (series or parallel). I think the jumper cables (and the car starter motor) will only "see" the battery to which they are connected.

Note: This is the OPINION of a ENGLISH major with zero formal electrical training. If I'm wrong the EE majors should step in and correct me...

Re: Using coach to start a car

Reply #4 – November 04, 2019, 08:15:21 am

It does not matter just hook the cables to a pos and neg post. Unless you have some exotic electric system it's all 12 volts in the batteries. By the way to avoid arcing hook jumper cables both positive terminals first neg cables last, disconnect the neg first once the vehicle is running.

Re: Using coach to start a car

Reply #5 – November 04, 2019, 08:40:19 am

Let me state this a little differently.

Your car and your motorhome both use 12 VDC batteries.

If you have 12 VDC batteries in the coach, yes, connect to any ONE battery positive and negative.

BUT, if you have 6VDC house batteries in the coach and want to jump off them, it IS a little different. Here, it is safe to hook to the positive with cable going to the house and ground going to the house.

Re: Using coach to start a car

Reply #6 – November 04, 2019, 09:11:59 am

Thanks everyone,
It started

Re: Using coach to start a car

Reply #7 – November 04, 2019, 09:30:03 am

Let's hope your car doesn't catch the 'coach buck virus' from the intimate contact with the coach. 🤣

Re: Using coach to start a car

Reply #8 – November 04, 2019, 09:37:09 am

We carry a Dihard battery charger/starter that requires a 120v outlet. We use the inverter and an extension cord, so won't have to disconnect the toad. You can also get the newer, portable battery starters that can be found at Costco and everywhere else. I also carry 12' jumper cables, but haven't stretched them back there from the battery compartment. If you have a tag axel, I think you have remote terminals conveniently located at the rear of the coach.

Re: Using coach to start a car

Reply #9 – November 04, 2019, 09:48:34 am

I also carry a battery charger.

Re: Using coach to start a car

Reply #10 – November 04, 2019, 09:58:57 am

I have one of these. My brothers Monaco start battery went dead while at Ohridge Campground in Sept. He tried his boost switch no luck. As he was getting his Tahoe to jump I grabbed the XP-10 he laughed at me and said no way could that little thing start his ISL. After it started he went online and ordered one.

AntiGravity XP-10 Micro-Start, Portable Jump Starter

Re: Using coach to start a car

Reply #11 – November 04, 2019, 11:03:59 am

Craneman how in the world can you get any cranking amps through those little wires. Not doubting you I just don't understand.

Roland

Re: Using coach to start a car

Reply #12 – November 04, 2019, 11:21:34 am

I use this one for portable jump start for my dinghy, never tried or needed for rv.

QuickCable LiFePO4 800 Lithium Jump Pack and Charger / Maintainer: BatteryMar...

Re: Using coach to start a car

Reply #13 – November 04, 2019, 11:21:57 am

Quote from: Roland Begin – November 04, 2019, 11:03:59 am

Craneman how in the world can you get any cranking amps through those little wires. Not doubting you I just don't understand.

Roland

I have used this for my cranes for years. Starts a completely dead 3208. My brothers battery was so dead that even his boost wouldn't start it. The wires aren't as little as you would imagine and being very short allows the amperage. You cannot just keep cranking, the engine does have to start in about 10 seconds.

XP-10 MICRO-START Jump-Starter – Antigravity Batteries

Re: Using coach to start a car

Reply #14 – November 04, 2019, 11:23:09 am

Quote from: Jack Lewis – November 04, 2019, 11:21:34 am

I use this one for portable jump start for my dinghy, never tried or needed for rv.

QuickCable LiFePO4 800 Lithium Jump Pack and Charger / Maintainer: BatteryMar...

Too bad they won't sell it in California or I would upgrade.

Re: Using coach to start a car

Reply #15 – November 04, 2019, 11:25:31 am

I have one of those lithium battery jump starts for my Jeep. Works great. Not sure if it would start my M11 but they do work. Mine has 21000 mAh and 2000 amps starting, so maybe it would. But wouldn't go anywhere without it.

Re: Using coach to start a car

Reply #16 – November 04, 2019, 01:31:04 pm

I have one of those little jump starters. It will start the Jeep from leaving the lights on all night, and it's 6 years old. Also charges phones and such. Still holds a charge of a long time.

Re: Using coach to start a car

Reply #17 – November 04, 2019, 01:53:24 pm

So, after I got Moms estate mostly settled, we went back to Tx to get Alice. Naturally both batteries were DEAD, capital DEAD.
No worries. AAA gold with the RV Ryder. I told the nice dispatcher what we were dealing with and that a battery pack would most likely NOT work.
What does tech show up with?
Yeah.
Long story short, we did start Alice, but not before his battery pack caught on fire.
Good times.

Re: Using coach to start a car

Reply #18 – November 04, 2019, 02:36:10 pm

Quote from: Moby – November 04, 2019, 01:53:24 pm

So, after I got Moms estate mostly settled, we went back to Tx to get Alice. Naturally both batteries were DEAD, capital DEAD.
No worries. AAA gold with the RV Ryder. I told the nice dispatcher what we were dealing with and that a battery pack would most likely NOT work.
What does tech show up with?
Yeah.
Long story short, we did start Alice, but not before his battery pack caught on fire.
Good times.

Like I posted not for continuous cranking. 10 second bursts and let the battery cool.

Re: Using coach to start a car

Reply #19 – November 04, 2019, 02:57:27 pm

Quote from: craneman – November 04, 2019, 02:36:10 pm

Like I posted not for continuous cranking. 10 second bursts and let the battery cool.

I tried telling him.
Really I did. More than once. Refused to let the jump pack do its job for more than 30 seconds.
But heck, what do I know?🤣😂

Re: Using coach to start a car

Reply #20 – November 04, 2019, 04:27:23 pm

Gosh, Frank, you've got a 450 HP Cumins...just push it!

Re: Using coach to start a car

Reply #21 – November 05, 2019, 10:12:35 am

I also have a Costco portable jump starter.
It did not work.
My battery was REALLY drained because I left the Engel refrigerator on and plugged in for 3 weeks.

Re: Using coach to start a car

Reply #22 – November 05, 2019, 11:04:47 am

Quote from: Lt403 – November 05, 2019, 10:12:35 am

I also have a Costco portable jump starter.
It did not work.
My battery was REALLY drained because I left the Engel refrigerator on and plugged in for 3 weeks.

Costco jump starter is nowhere near the amps needed to start a diesel. It should have started your car. Let it sit hooked up for a couple of minutes before trying to start. I use one for garden tractors and roto tillers.

Re: Using coach to start a car

Reply #23 – November 05, 2019, 11:15:02 am

Does not take much planning to have a set of jumpers in either the toad or coach. Start the toad and fast idle for 15 minutes and your diesel will come to life in most cases. But a set of batteries flat for 3 weeks is going to be damaged and may need more than jumper cables. Probably going to take a credit card to get the engine to turn over.

Don't expect much from $10 cables. Best is making your own from welding cables.

Pierce

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