I finally tested to install a battery switch for the negative/ground terminal on the annoying trunk battery placement in my gen 2s. I wish to recommend this to everyone DIY since it makes me able to cut power over winter or when doing maintenance work without even removing one piece of the trunk pieces. Just by opening the right backlight cover I am now able to reach this switch and cut 12V. This might have been posted before, but I failed to find anything like this. I bought one version from temu first, this had the best design in my mind. I had to grind the pole down a bit, but this version has adaptable screws that easily fits the small sized poles that the Prius uses and locks them into place real good. IMG_0662 by priumium posted Dec 4, 2025 at 6:18 PM
That's a great looking design but there's no way I'll buy it from Temu. I wonder who else sells them?
(Why not temu? Tariffs? Sex dolls..?) For your information I have failed to find this much smarter design anywhere else. Contact the seller directly and ask, it seems like a very much smarter version with the screws. I bought four different designs from AliX and the other ones are all to big for the poles and are also hollow (bad for grinding) and without screws! Easily fixed with a drill, but I have now bought three of these instead.
a car battery disconnect switch versatile - Temu Sweden It’s so versatile…? This concept is vital to save the hybrid battery when not using the vehicle. The 12V gets charged when low from the hybrid battery = kills the hybrid battery if stored/not used. SAD.
There are also switches that don't directly connect to the battery posts. Depends on the application, ease of access.
Yeah. If I was going to do this I would pick up a battery to ground cable at the junk yard and splice a switch into it.
Those are marine versions and are good, but the switch is then loose unless you fasten it to something sturdy. That’s a big plus of this design (pun). This was flawless in my mind. Reachable from the lower cover.
Even on an older Prius, don’t you lose some settings when you disconnect the battery? also, do you have a link for the posted picture?
Indeed, radio channels, clock and so called learned values are reset. That might be befinitial in some scenarios. I am not sure how fast this happens, Toyota states 90 seconds to empty all current.
No, I do not, but running short trips when the battery is in bad shape or has been emptied previously and lost 80 percent capacity to store the charge, the hybrid battery will waste many A on it, especially when below zero. When stored the 12V gets destroyed due to many many factors. It’s even in the manual to disconnect it when storing for more than a couple of weeks, as you know. When big subzero, this value can be a few hours..
Maybe in your translation? Just curious, I don’t recall seeing that in the North American owners manual.
The instruction is to loose a bolted cable under the jump start red bracket (@hood) and leave cable disconnected if the engine will not be started within 10 days (if stored or very cold). I am certain this is not a special instruction for the Nordic’s - but it is likely from another source than the owner manual unfortunately…. I will post this when I find it.
Interesting. My takeaways (for a GEN5'er) -You can isolate the battery in the trunk by doing something under the hood, for GEN2 at least. (Now that I think about it, it makes sense.) -GEN2 used AGM batteries. Mine is a flooded model. Progress?
Thanks for finding and posting that. Interesting, the first attachment in post #15 refers to the proprietary Toyota charger as a “trickle” charger. Granted it’s a misnomer, but some here lose their minds if the term is used incorrectly. Language is an evolving concept, many words came to be because of confusion, or their meaning shifted over time, that’s just how it is.
This is one version I also tried, made for marine usage and that needs an extra battery/ground cable. Works great but needs to be fastened to be stable and easily reached.
I ”love” those TSBs, they are the only source of confirmed Toyota issues. Notice for everyone; these TSBs are not any kind of official recall: it’s instructions for dealerships what to do with issues identified after the initial workshop manual was released. So they are gold for any DIY in my mind.
