Jumpstart from auxiliary battery

Ok, I had the opportunity to try a terminal to terminal jump on the isolator, and it worked just fine.

Earlier in this thread I mentioned that the Jump&Go was possibly under recall, but the manufacturer hadn't responded to my email. The manufacturer has since responded, and said that a few units were under recall, but I should be able to buy one from another Walmart. I went to another Walmart and bought one without incident. I wanted some auxillary power for my iPad anyway, so this is a good multi-purpose solution.

Also, I had noticed that the battery was an AC/Delco, which made me suspect that the battery had never been replaced on the 2007 chasis of the 2008 Roadtrek 170. So I bought a new battery as well.

With roadside service, jumper cables, the ability to jump from the auxilliary battery via the isolator, and a new battery, maybe, just maybe, I'm covered.

If I still have troubles, I'll start troubleshooting for current leaks.

I appreciate all the replies and ideas.

The other thing to keep in mind is that a boost switch can vastly increase your emergency-driving range in the case of an alternator failure (which, as failures of modern vehicles go, may be one of the more common ones). Indeed, if you have a genset, it can extend it indefinitely. If you vehicle has an isolation relay and adequate wiring, this mod is so cheap and easy that it seems like a no-brainer.

Our house batteries trickle charge our chassis battery. In theory and hopefully we would not have to jump start in that situation with 420w of solar panels and 800ah of lithium ion batteries that would, in turn, get charged by the engine with a second alternator and with high idle auto start if they got too low. That's kind of a round robin solution you would have to be very negligent to defeat.

After a new chassis battery failed on our first Roadtrek (1996) and we were in the middle of the Redwoods in northern California, on our return home, I had our local mechanic wire a coach battery boost switch. I wouldn't be without one. It was one of the first modifications done on our present rig and worth every penny.

goboborz, if your 170 has a continental kit spare tire carrier you can carry those long jump cables in it. I used the carrier on our 210 to carry two items I seldom used: jumper cables and fifteen foot of extra hose for the macerator pump.

Here is what I did: removed the cover on the spare, wraped the jumpers in a circle and tied them in the wheel recess with heavy duty twist ties (not the kitchen ones but the kind you get at the garden supply to tie plants). Did the same thing with the hose on the other side. You can put what you want access to most often on the side of the wheel facing the RT, what you might or might not need on the other side behind the fiberglass cover. I found this to be a great little place to store coiled things like that which were seldom needed. I don't think I used my jumpers but one time in the seven years we had the RT.

Since storage space is always at a premium in a B (or any RV because of the "if you got it, fill it" mentality) this is just another cranny to use.

PSW

FWIW, We have an 04 Popular on the Chevy chassis. From the WEB it is apparent that some of these units have a parasitic current flow that will run the battery down when not used for about two weeks. My solution is a battery disconnect on the negative battery lead and a Priority Start on the positive. (www.prioritystart.com). The Priority Start protects me when I accidently leave the lights or something else on and the disconnect prevents discharge when parked for a long period. The priority start draws a little current after disconnect and that small draw as well as the battery internal loss will eventually result in a totally dead battery so you still have to restart before the charge is totally gone.

goboborz - Just a little caution.:D If your chassis battery is really dead, making a connection between the two positive posts on the 2 batteries may create a sizeable spark. Be careful that you do not blow up a battery by igniting the battery fumes.

That is the reason it is recommended to connect the negative post of the good battery to some metal bolt on the dead battery vehicle. That keeps the sparks away from the battery. You cannot do that when the negative posts are already connected together by the steel frame of the RV.

Thanks Mike, The battery has never gone completely flat, and both times the engine wouldn't crank it would still turn over - barely. Two different Advance Auto stores have tested the battery and told me it's good. I'll take your good advice on tracing the leak, while still going forward with the isolator terminal-to-terminal jump experiment.

well if your battery is duff replace it

a bad battery can stress the alternator to the point of failure.

they get old and loose chemical balance , the plates sulfate etc....think of a weak battery as an anchor.



as for current drain- #1 cause is leakage through moist dirt on the battery case.
clean it

2.) you should probably only have alarm and radio memory drawing power when parked.

you can pull fuses for the radio and alarm and should then have "zero" amps flowing from the battery- a multimeter will be handy for this, you connect it in series.

if you see any current flow, continue to pull fuses until it goes to 0.

then replace all but the last fuse and watch the meter.

you can determine if there is a fault somewhere and how to solve it.

mike

A lot of good suggestions here. Thanks everyone. I think I have a very slow current leak somewhere, so I want to make sure I'm covered.

I tried taking 1775's suggestion and ordered a Jump&Go online from Walmart. When I went to the store to pick it up, they wouldn't give it to me because they said it was under recall. So they refunded me. I emailed the manufacturer and asked about the recall, but haven't heard back yet.

I bought a 20 ft jumper cable set from Home Depot for a very reasonable cost as PSW suggested. It reaches from from the auxillary battery to the starting battery with length to spare - at least on the Roadtrek 170.

A long time ago I had one of the isolator bypass switches inside the coach of a Fleetwood class C and it was very handy.

I'm still toying with the idea of a terminal to terminal jump directly on the isolator. I've determined the terminal that the wire from the auxillary battery is from. The terminal that the auto battery is from is obvious. It seem that I could just connect those with a short jumper cable and it would work for jumping. It shouldn't need a ground cable. I think that's probably what wsfurrie did, and he said it worked. Right wsfurrie?

At any rate, the next time the starting battery gets weak, I plan to try the terminal to terminal jump with my existing jumper cables to see if it works. If anyone knows that it will blow up the neighborhood please let me know.

If that works, I'll just get a very short jumper cable or make one. The 20 foot cable and it's storage box takes a lot of room (relatively) in a Roadtrek 170 that I live in much of the time, so I will store it.

The idea is that the auxiliary battery will always be up, or at least can be charged with the generator if it's not. So it should always be available for jumping unless I run out of gasoline.

Thanks again!