Kinda an odd problem about my 12V battery-cables

The other end of that heavy cable is connected as the supply source for the underhood fuse box in the upper driverside of the engine compartment. There is no real slack to be had.
You'll either need to get the crimp fitting removed, opened up and recrimped/soldered, OR do what some others have done and find a salvage yard that has a gen 2, cut that cable several inches back and crimp/splice the new piece of 'yard' cable onto yours. You don't want to make a loop in the wire, so you'll need to trim it as needed to get the correct original length. Otherwise it's just a pain to stuff it in place.

 

but, for that size wire and ampacity, is less common, and requires the heavy crimp tools they have at your neighborhood independent auto electric shoppe.

I would probably try to get the last foot or so of that wire out of a salvage car, then take it to my neighborhood auto electric shoppe and have them make it up. They'd charge me less than the cost of a heavy-nice-person tool I might never use again.

 

If it goes to Ready with the short salvage battery wire jammed into the remaining vehicle harness it might work for a short time. A battery that could not staying charged before has no chance with a battery cable rigged in that manner.

To properly repair using a salvage pigtail (piece) it should be crimped or lugged at the spliced connection.

Crimp sleeve for wires (sized for wire diameter - typically 4-6 awg with automotive stranded)



Lug Butt Splice (tighten with allen wrench and insulate)



Amazon Butt Splices



Once you splice the wires together, you still need to do something about your battery. It is likely weak and needs testing and replacement as indicated.

Again, a good battery adequately charged won't freeze. How many of your neighbors are removing their battery every night? Some will attach a battery maintainer as I have when in Calgary during the winter. Many do nothing and still crank their high amp starters.

A Prius 12v battery does not have to supply large currents and is in the cabin rather than under the hood. After achieving Ready, a weak battery can initially charge by drawing 60-80a from the hybrid system. A loose, "jammed" connection won't do it and is likely to fall out and short the battery. At best you can be stranded somewhere.

 

The markings on that splice identify the not one but two distinct special tools and dies to be used to properly crimp it onto the wire.

Your neighborhood independent auto electric shoppe already has the right tools and dies to do that, and when they're done you'll have a properly all-around-crimped and insulated connection, more reliable than the set-screw butt connectors, and they'll probably be done in a couple minutes and you'll be on your way for a nominal charge.

 

Have I missed something? That seems to be the first mention in this thread of that code—which isn't really a code (real ones are five characters), but P0A08 and P0A80 are both real codes (meaning quite different things). One of them has nothing to do with the 12-volt electrical system.

Is your car giving you either of those codes?

Or are you worried about a prospect of seeing one of those codes after repairing the broken wire?

 

Given it was running before the 12v wire broke off it would seem the hybrid battery code is secondary now even though it needs a solution in the next month or so.

In your situation the easy and functional 12v splice is the Home Depot splicer that you tighten with an allen wrench or dcrewdriver. Then wrap with Self fusing tape or Scotch (3M) 33+ electrical tape, both available from Home Depot.

You splice the piece on when its not connected to the 12v battery. No electrical concerns during that installation.

You can get a auto shop to crimp the appropriate Napa crimp sleeve later.

Around here Home Depot will deliver the same or next day if parts are in stock. However it would be much better to take your salvage yard piece in and verify fit.

 

A good crimp with a proper tool will be superior to the screw-tightened splices.

The screw splices will get the job done and not require relying on a shop or an expensive investment in tooling.

Although it travels in a harness that may also contain other wires, what connects to that one large single-terminal connector is a single, large, wire. It is a stranded wire, made of a number of thinner copper strands twisted together, but that's still considered one wire.

Make sure that whatever splicing you do involves only that one, large, stranded wire, and not any other wires you may find in its vicinity.

 

The screw type splice is just fine and is made for the job. Heating is really not a concern because high amps only occur for a short time. Regardless all of those splice devices can take the amps.

If this was a conventional 12v starter car, a screw type splicer might last two to five years. But this application is much less demanding.

I suspect a friend or neighbor could help you do this quickly and easily. Its not that big of a deal.

 

Your pic


The thick black multi strand conductor on the right is the main 12v cable. The multiple strands ("wires") inside are built that way to make the cable flexible rather than one huge diameter conductor. All of those strands go into the splice device.


Factory Setup


The thin white wire is separate and is for remote monitoring of the battery voltage. It is not included in the splice. You already have it separated and taped together in the first pic above.


Schematic for Tech Reference

 

to allow for a proper repair.

After seeing your photo, which includes the (+) battery post, you need more help than just a splice. Quit jerry rigging and get it fixed correctly so you don't have to worry about breaking down. You're worried about a "correctly done splice" but have no worries about the (+) post? That terminal post clamp is available for about 15 bucks new. These are the things that drive me crazy when customers complain about something not working...........Crazy...............