Has anyone hooked up an auto battery in parallel to the bike battery as opposed to replacing the bike battery entirely? Seems this would double the capacity and not the voltage. More power!!!OOHH OOHH 🙂 Don't see any problems but thought I would ask the experts.
Hey Bill,
Hooking an aux battery in parallel will work fine. Connecting them in series will cause the magic smoke to leak out of many of your electrical components!
What I worry about with connecting a battery in parallel is the length and guage of the wire/cable. Realize that if you have the aux battery connected during the start cycle, you could be pulling 50+ amps over the wire. To handle that, you'll need some pretty thick cable. I've seen some wire gauge calculators on the internet that take length and load and yealds the minimum wire guage to support it.
Another thing to keep in mind is putting a fuse on the wire, particularly if the battery will be in the hack. That's a mighty long way to run an unfused cable capable of dead-shorting your battery!
If your intent is to provide power during the run cycle (i.e not start cycle) then you can put a battey isolator in the circuit. Basically, it's a relay that breaks the connection between the batteries while the starter motor is energized. The advantage being that you can run smaller guage wire and a smaller fuse. You could pack a set of jumper cables if you think you might need to get an "emergency jump" from the aux battery to get you home. Check with your local RV shop if you are interested in battery isolators.
Thanks for your input. Have been planning all along to replace the bike battery when it gave up the ghost as I did in my other rigs. But,seeing as the bike battery is under the tank thought I might do a little preparation since Murphy's Law will probably have me at least a couple of states away at an inoportune time. I have installed the battery box and made arrangements for the cables (access hole) but that is as far as I have gotten.Thanks again 🙂
Bill D
Not a particularly good idea unless the batts are indentical, then it's fine.
If you want to get bored with all the technical reasons, let me know and I'll do it in a PM (it's lengthy), but think in terms of weakest link.
Thanks for the reply Michaelh. That was actually a concern I had from the beginning. Think I will install the cables and let it ride, I can always buy an automotive battery on the road.
Bill D
Being a noob, what I know about sidecars you can put in a thimble, and still have room left over for a good snort of whisky, but I've worked bunches on storage battery systems.
I am thankful I know a little more about sidecars in general than battery storage systems. That is why this forum is great, we can all help out with our personal experience. Thanks again!
Bill D
🙂
