These critters boost voltage up. Way up.
Then at the batteries, another type unit (same ad look down the list) will BUCK voltage down to whatever you set the potentiometer to.
Yep the bucker at the batteries could easily use a boost fan.
A pair of 36 volt tiny muffin fans would do fine. Silent. Wire them in series. Feed off incoming voltage. In pos / neg to 2nd fan pos / 2nd fan neg to incoming boosted voltage negative.
No need to fan the underhood booster module. Your radiator fan will blow plenty of air.
BATTERIES decide how they want to be charged. Not a demented auto manufacturer engineer. BOOST BUCKING can deliver correct charging voltage to a demented new vehicle's house batteries. Paranoid about reducing voltage to a costly set of batteries (?)...use an analog solar controller to reduce voltage. Wheeeeee... your alternator becomes a SMART alternator (whoopee)
