Charging 12 volt battery while terminals connected to car

Yeah the 2016 battery is looking very conventional, with exposed caps on the top. Likely a bit more prone to venting.

I've been guilty of occasionally connecting both clamps directly to the battery, but it's better practice, to do the negative clamp last, to bare metal (either a decent bare metal bolt on the body, or a part of the engine), away from the battery a bit.

Another trick, that I never hear mentioned but makes sense to me, lol: blow across the top of the battery just before doing any connection. If there's any hydrogen lingering (batteries invariably give off a little, and it IS very flammable), should dissipate. For starters, it's the lightest gas, well: in the universe.

Eric the Car Guy made an astute observation (another one I'll admit to rarely following): when working with automotive batteries, at the least wear safety glasses:



So if the battery blows, spewing acid, you'll look like Phantom of the Opera but at least be able to see. For better protection, a full face shield is better:



I really should get one of those. It's a hassle, but yeah, maybe a good idea.

 

As have numerous other folks here with Gen2 and Gen3 models, over the years I've been here. Myself included. But not universally so, any problem with this is related to driving patterns. I don't drive daily anymore, and mine now tends to get many short trips in between the long ones.

But since Gen4 made a significant change to the 12V battery, I'm inclined to wipe that slate clean and wait for a new batch of reports on the new generation.

 

tks David and Mendel. i have actually seen sparking on occasions. thankful to still be alive

 

I recently was reinstalling a jump pack battery, and made the bonehead decision to connect both terminals loosely, then tighten. As opposed to dealing with positive first, getting completely done with that, then going to the negative.

At some point my ratchet extension managed to bridge from the positive terminal to a wire leading back to negative post. There was a loud pop, cloud of smoke, and the wire just kinda melted. Scared me good.

 

Yep, I've got a (too large) shifting (adjustable) spanner with scars from that dating back from 1972.

 

My thoughts are that PRIUS would be different from cars of old. What happened then, is that the cranking of the engine (worse if it was a cranky engine) would decrease the battery reserve, and with short trips would eventually mean the battery wouldn't have enough for the next crank. PRIUS 12V doesn't have the stress of cranking the engine, so I'm surprised that, unless it's being used for extended radio use etc, the 12V declines, unless it's actually dying.

Something with battery design though in the last 15-20 years. Prior to that, if the battery was dead and you jump-started it, you could drive for ½hr and it would completely charge up. But modern batteries don't sufficiently - if they go dead, you'll be advised to charge it up rather than drive it to charge. No, I don't know why.

 

I have the BatteryMinder 1510 and it works well.

Have almost 8 years on our Prius Battery and 6 years on the 4Runner.

Both cars get usage daily and I do a once a month cycle with the Battery Minder.

Good choice.

 

Yikes! My father-in-law got a nasty burn from his watch band when the current went from battery positive to the wrench to the metal watch band to the car. It was several weeks before he could wear the watch on that wrist again.

 

How long do you leave the Battery Minder 1510 connected? Just till the charge cycle is completed, or longer? Thanks

 

I timed the first cycle for each car to get a feel for the time commitment. Both were between 6-8 hours.

I usually go 9 hours to ensure the cycles are completed and it is in maintain mode.