Just thought to myself, the idea of 'servicing' ones hybrid battery, talking about OEM ones from factory. As a preventative measure? A bit like the EGR preventative cleaning. Sure you service/clean the intake fan for the hybrid battery to ensure it performs as expected and doesn't overheat. However what about every few years/50,000 miles? Disassembling in order to move the battery modules furthest from the fan/in the centre that would experience less than idea cooling and the most heat which in general degrades batteries as opposed to the others, clean the bus terminals/nuts and reassemble? Would such a thing be worth it? Wouldn't require any specialised equipment apart from voltage protection etc.
If able to DIY, yes, I would inspect/ clean the terminals/ nuts. Sure 50K mileage or 5 years, every other year, maybe not. That seems like good/ worth while preventive maintenance. Not sure if any specialized tool is needed. Regarding the module moves, I have no comments or insights.
I got the idea from a YouTuber who makes a fair point, even in terms of gaps between the modules, if clogged with hairs/debris or whatnot can reduce airflow. In general I would think if your hybrid fan is 'dirty' most likely your battery modules will be too.
yes, several people here have done similar over the years. it generally depends on what types of contaminants are in the car.
The older Prius didn't have air filters; the newer ones do. 50K mile teardowns seems a bit excessive; since they average over 15+ years or 150+K miles before they go bad. Less if the car isn't driven daily, more if they're on the highway a lot. Every 10 years or 100K miles would seem to be a realistic measure. Every car sold after 2020 carries a 10 year 150K mile traction pack warranty; but I believe they all have filters by then. If you have the time and money; go for it. Just know that anything over 50VDC can be dangerous. Those are 200+VDC packs. You don't want to end up like those toasted rats I used to pulled out of giant battery UPS units.
It wouldn't be worth it. There is a filter you can purchase to put over the intake vent. And you can also get filter material to cut to fit to put between the two. That is what I did. Keeps the fur out, and 90% + of the dirt and dust. It worked great. When I removed mine and tore it down, there was just a fine covering over the modules. The fan just had a thin film on the blades. And only a few pieces of fur. And I've had larger dogs in the back of my Prius several times a week for since I got it. Moving them around really won't make any difference either. And you'd likely have to balance the pack because the ecu would be expecting to certain voltages and now they're different. With your low mileage, it's probably very clean. Unless you've had dogs in the back and/or drive with the windows open and it's very dusty where you drive. You could remove the pack cover and check the connectors.
Yeah the only issue is the safety aspect. If I do go OEM route it'll be new, and wouldn't be too concerned with debris etc. Just mainly about the packs heat distribution and basically "rotating" them from early on otherwise later on won't make a difference. I wouldn't think they'd need to be rebalanced as long as they are moved around within their pairs? As the computer module deals with pairs and overall the voltages/capacity etc wouldn't change at all. Just basically the #bank positions.
It might not matter what the arrangement is. But then it might. Why take the chance? A lot of work removing/installing the the assembly, then removing the each block and reinstalling...... I personally don't think it's something you need to worry about. You drive very little. The computer remembers what the readings are. If suddenly, the reading are different than average, in several positions, you could get an error code. That's why I said balance the pack. You could also reset the ecu before taking the battery out.... I think disconnecting the 12v battery will do that. Since you are going to disconnect it when you work on the hybrid battery, you shouldn't have to worry about it. My brain was slow.... took time to catch up... Still, no NEED for rotating the blocks....
Cleaning the fan filters and checking the bus terminals would be a good idea, as you can do it fairly easily with the battery still in the car. I wish I would have done that as mine was fairly corroded by the time I got to them (13 years later). Moving the modules would require taking the battery out of the car and disassembling it. Not worth it unless you are actually trying to repair the battery. Just monitor the modules' health with Dr Prius. The only other maintenance I would do is to 'rebalance' the modules once a year with a grid charger. The modules' charge level/voltage tend to drift after many charge/discharge cycles, especially since the BMS tries to keep them the middle charge range. This can cause an error code if the difference goes beyond 0.3V. The grid charger will 'recondition' them by going through several full charge/discharge cycles, and sets them to approximately the same state of charge at the end. Lots of threads here on how to build one, and once you have the harness installed, you don't even have open up the battery compartment to do this. Just plug it in and run it over the weekend.
