I guess there is some distinction to be made between keeping electronics cool and keeping batteries cool. As noted above, batteries should be kept at an optimal temperature and the other ventilation consideration is to reduce gas build-up to minimize risks of explosion as well as corrosion.
Electronics (as distinct from electrics) need to be kept cool (but not necessarily as cold as possible, which would have a different set of cooling requirements, including refrigeration) firstly to continue to function as designed and secondly because conductivity improves with reduction in temperature. The fan in you laptop or heat dissipating fins on your inverter are examples.
The same applies to battery and electrical leads but in the normal range of temperatures experienced in automotive use this is not a big consideration. I've worked on drill rigs whose start batteries are in the sun at over 50C air temperature, plus they are right alongside a pile of mechanicals and hydraulics bellowing away at full power for 12 hours continuously. There is no way they are at their optimal temperature, yet under normal use and charge parameters they don't boil or fail to perform.
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