When parked after driving--typically after 12 highway miles @60 mph, then 3 miles @40mph--wondering if reliable information or data might be available indicating significant difference in Gen 4 2017-2022 retained vehicle heat/warmth attractive to rodents for nesting in cold weather...between NiMH vs. Li-Ion battery models? Reason for this odd Q: my 2018 Prime w 76k miles just declared total loss by insurer after rodent urine entered Li-Ion battery, despite numerous rodent mitigation measures (e.g. no charging at night, no food in car, trapping up to 20 field mice/week, wire mesh above cabin filter, balsam fir oil deterrent, etc) after rodent-damaged wiring harness needed replacement in 2020. Live in semi-rural MA town nearby wooded areas providing wildlife including rodent habitat. However 2010 Prius in same location for 8 yrs had some rodent nesting signs, but not any damage that required repair. Insurance agent says another rodent damage claim would probably cause non-renewal or cancellation, so want to replace Prime w less valuable used non-plug-in 2017–2022 Prius...most models Li-Ion battery, but NiMH available on 2017-2018 trims One and Two, and AWD's since 2019. Have read that Li-Ion battery generally generates more heat during charge and discharge…on other hand NIMH approx twice the size and heavier, and Toyota reportedly has invested R&D in lithium cooling technology so choice not clear to me. Am willing to accept lower mpg and performance with NIMH if vehicle parked after driving retains less heat and/or for shorter period of time vs. Li-Ion, but so far haven't found any reliable information or data indicating significantly less NIMH heat attractive to rodents in cold weather. Also--was surprised and disappointed Prime lithium battery containment was capable of being penetrated by rodent urine…vaguely recall thread seeming to indicate NIMH containment might be more sealed/protected than lithium because greater lithium heat needs breathability to dissipate heat more easily, but not clear. If NIMH containment/sealing is more protective than Li-ion, that would seal the deal for me in favor NiMH. Would welcome and very much appreciate any reliable information or data related to post-driving retained heat differences between the two batteries. Thanks much! James
Lithium is more sensitive to maintaining a constant temperature, does not like cold temperatures. NiMH is more unpretentious, so it tolerates cold temperatures easier, but in a very hot climate the battery heats up and fails. It is not clear how mice could crawl into a high-voltage battery. The technological holes are small. Is there a mesh on the ventilation grill? I think the issue is not the heat of the batteries, but that the grates do not cover the holes through which the mice enter.
There’s a couple more egress points, assuming it’s similar to gen 3, at the sidewall back corners below hatch floor, exit vents for the hybrid battery, with flexible material flap/louvres, sim to a dryer vent. Likely simplest, and what I did, was remove back bumper and fashion little rodent mesh boxes to cover from the outside. the vents have plastic frames you can screw into, avoids creating rust points.
IMHO; It really doesn't matter. An animal is just looking for someplace warm and dry to bed-down in. They don't really care if it NIMH or Li-ion cells they're sleeping on......
It’s hit or miss, not one car vs another. My 2012 was parked in the same garage for 7 or 8 years no problem, and then one day the mice took over. No problems since
