I have never used them in my life and everything I own starts up just fine whenever needed but I do have a heated garage so that probably helps. I don't trust them. I hear too many horror stories of them burning down garages or causing fires from shorting out or over charging batteries.
1963 Belvedere 440 Max Wedge Tribute
1970 Charger R/T S.E. 440 Six Pack
1970 Challenger R/T, 528 Hemi
1970 Charger 500 S.E. 440 4 BBL
1970 Plymouth Road Runner 383
1974 Chrysler New Yorker 440
1996 2500 RAM 488 V-10 4X4
2004 3500 Dually Cummins 4x4
2012 Challenger R/T Classic.
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