Battery terminal cover

Hello guys.

Yesterday, my neighbor and I got together to show off our identical Lexus IS 300 fsport. And during physical inspection I learned that his IS has two battery terminal covers and mine doesn’t.

How important are battery terminal covers ?

Also, his coolant level was higher than mine but his IS has 25k miles on it and mine has 43k.

My dad keeps telling me that my coolant level is too low but Lexus told me that the level fluctuates. They didn’t add more.


Only one is important… the red one on the positive terminal. The black one is for show.

Coolant level is explained in the owners manual. Read it. As long as it is above the minimum and below the max, you are fine. The level does not correspond to mileage. If the level is dropping, you have a problem… see a mechanic.


Thank you. I’ve learned something new.

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You should have learned two things not just “something” Read the manual!

Why is that? Had cover no cover, Never noted a problem one way or another.

I doubt the owners manual indicates which trim levels come with a negative battery terminal cover, I see many late model Lexus IS cars with only one battery terminal cover.

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The cover on the positive terminal protects against short-circuiting the battery, which can be an under hood catastrophe. Say if the hood contacts the positive terminal, or a wrench touches it and ground simultaneously…

Anyone had that experience for more than a fraction of a second? I’d like to hear about it. Not gonna do it myself!


I don’t like them but that is one good thing about GMs side post battery’s

My 2012 Camryhas maintained a coolant level about 1 " below theadd coolant level on the jug. Has done so since new as has my nt added is forced out when driving,daughtersRAV4. Radiator on both of them stays full and any cool. Neither has ever shown any signs of overheating but there is no temperature gauge. What I had thought was the temperature gauge is actually a average gas mileage gauge. I can’t drive with my reading glasses on and don’t need glasses for distance.

You only have to accidently lay a screwdriver or wrench across the Positive (Red) terminal once and it’s plenty of trouble. Every car (a few prior to 1956 had positive grounds…) uses Negative (Black) as a ground and if you lay a wrench across that, nothing bad will happen. But as they say on TV, “Do Not Try This at Home…”

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I doubt the OP or most Lexus owners have a wrench. Why would they raise the hood and place a wrench on the battery?

Drop a wrench on the positive and if it hits metal big sparks. Drop a wrench on the negative, nothing.

How about a mechanic who accidentally drops a wrench and it lands on the battery?
The cover makes for one less hazard, for everyone.

This all brings to mind the VW Beetle and its battery under the passenger’s seat.
If you forget to put an insulator on that battery when a passenger sits on the seat with its metal springs they can get a literal hot seat.


… and let’s nor forget the “joys” of jump-starting an old Beetle. Getting jumper cables to reach back there was frequently problematic.

Even my lawn mower has a cover on the positive terminal under the seat. Always wished I had a heater in it. Thinking, thinking.

The coolant level in my Corolla’s plastic bottle varies by 6 inches or more, lowest when the engine is cold, high when the engine is at operating temperature. I put marks on each spot and check them occasionally to tell if there’s any systematic change. Coolant level may drop slowly over time as well, as entrained air is burping itself out, or perhaps the water pump seal is weeping a little.

On a flat surface, I could push a Beetle fast enough in neutral, jump in, put it in 2nd pop the clutch and drive on. Of course I was much younger then.

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At Sing Sing prison they called that “the hot squat”.

Very true for me, also. My problems with jump-starting a Beetle were as follows:
When my brother was sent to Vietnam, he left his VW in the care of his new wife. She wanted no part of it, so she essentially gave it to her father, who used it (rather than his Caddy DeVille) for shopping trips of one mile or less. The short-term result was that the battery would go flat fairly often, and it became my job to jump start it.

Because they lived in an urban area, the VW was always parked at the curb–hemmed-in very closely by other cars–thus making it very difficult/ impossible to get it out of its parking space in order to push-start it. IIRC, the battery was on the right (passenger) side of the car, under the back seat, and getting jumper cables from my car–on the driver’s side of the VW–was a real PIA.

The long-term effect of that consistent one-mile drive routine–coupled with Daddy Dearest’s failure to ever change the oil–killed the engine. :unamused:

If my brother had left the VW in my care, it would have likely lived for many more years.

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I gotta go but you guys are doing great this morning. I never had to push my vw, but regularly pushed my Morris to start it. Down town with my restaurant whites on. Embarrassing. Then my buddy and I pushed it up and down hills at the drive in theater so we could get home. Sold it.