Yes, Again, trickle/float chargers are fine If the socket is good. Many sockets are crap, often even when never used them to smoke.
Yes, Anything trying to start the car using the lighter circuit can blow fuses or worse.

quote Originally posted by 84fiero123: Using the frame as a ground has always been the preferred method for jump starting a car. Anyone ever actually see a battery that exploded or even better, see one explode?

Not really... Frame ground may work for a charger but not good idea for most things.
Almost Anything on the block is better because block has big battery ground cable. If you can access the block end of battery cable then that's the best most times.
BTJ and others w/ lug end can go directly the the battery or about anything lugs will fit. For Fiero Plus to box under C500 and Ground to frame, ideally same area where battery frame wire for keep it simple to track issues later.

boil off and "explosions" are mostly 1 to 3 things causing them...

"Dead" cell can short internally then the battery making allot of steam etc that can overpressure and burst/"explode" the case starting at any weak spot. Easy w/ Sealed Maintenance-Free cases.

Bad alt or external charger can over charge and quickly boil off electrolyte, very bad can burst the battery case same as dead cell. You often have better luck using 6a or less units to charge many car batteries, like Fiero battery. Many battery companies say 10a Max for most of them, Flooded and AGM.

Bad alt or other electrical items can short. A battery can dump 200-400 amps even more. That can wreck the battery and cause major damage to the cars. Battery may look ok and work after a big short but lifetime is likely very short. Most Fusible links and other fuses are there to prevent the battery having a melt drown or cause a fire when alt etc are toast.

small MC batteries does not need charging amps same as car/truck batteries. If not dead in the first place, you can boil them in less than an hour using more then ~2a charging power. Many "trickle" and "float" chargers are too much power for long term storage for MC.

[This message has been edited by theogre (edited 12-31-2015).]

All that tech blabla does nothing to explain why my chargers do what they do. On another tangent, why is it they say do not charge or jump boat batteries in the boat...your supposed to remove it to charge it. Ill stop by saying everyone charge your stuff however you want and ill do mine. I dont really care if you just run an extension cord from your house socket to the battery terminals.

[This message has been edited by rogergarrison (edited 12-31-2015).]

Nothing will explain why your chargers do what they do.

You really shouldn't charge a battery while it's in anything - because there is a remote chance it will explode. Batteries *should* always be removed whether from a car or boat before charging. I suspect they take boats a little more seriously because the failure scenario is so dire - an explosion or fire in a fiberglass box on the water would be a lot worse than an explosion or fire in a metal box on asphalt, and where cars are typically full of holes to vent hydrogen boats are typically not. There is nothing special about "marine" (aka, deep cycle) batteries other than their plate arrangement... which is what makes them deep cycle in the first place.

True deep cycle batteries will hate started any motor and won't last very long.
Starter batteries don't like even hate things DC batteries loves like running TV Tools etc for hours.

Marine batteries are "half-breeds," part starter and part deep cycle. Many Removable vent/fill types the caps/plugs are made to seal out water better car batteries. Water is bad but any salt in the water is big problems. Newer seal types are better.
Some car batteries are about same as Marine types like Optima Yellow Top on Dk Gray case. Can start the engine w/o damage and run TV etc but might not be as good as true DC.

Charging marine batteries in the boat can be bad because many things so most charger makers say take out to charge. 2 examples:
Most Chargers are not made for use in wet areas. Just using them in rain on shore can shock you.
Running a charger on a boat means pulling 120vac from shore. How good is your extension cord(s) for that? Any problem can electrocute anyone in range. Shore power might have GFI plugs but Charger makers don't know.