Lexus Oem Battery Clamps Not The Best?

[harrylime]

I charged my Battery the other day on my 400 and on refitting the positive clamp, overtightened a little and cracked the clamp . I rang Lexus and ordered a new one (for around £22) and then looked at the clamp again. It seems to me that they are relatively flimsy, ( it was also slightly corroded), and that something better must be readily available. I called Lexus back and cancelled my order to allow me to look around to see what else is available. I avoided my local parts shops and went to the local auto electrical specialist (they rebuild starters and carry out electrical repairs etc) with a view to getting a better quality part. They supplied one for just over £6, which I have just fitted. It is probably 5 or 6 times thicker than the original and just seems more substantial. I'm no electrician but it seems to me that this must help when the Battery is feeding the starter etc, and also when the alternator is feeding the Battery. The other observation I made was the plastic insulating piece at the bottom of the clamp achieves absolutely nothing except trapping moisture and causing corrosion to the thin metal in the clamp.

Have I found the one area in which the 400 is under engineered?

[OldTrout]

Smearing the Battery post with Vaseline before fitting the clamp will help keep it from corroding.

Weird I know but that is what car electrical places did last century.

John

[runsgrateasanut]

Smearing the battery post with Vaseline before fitting the clamp will help keep it from corroding.

Weird I know but that is what car electrical places did last century.

John

You may be wrong on this. I smeared vaseline on my Sons Battery terminals and he didn't start the car for several weeks. When needed to remove the car to a different location not a thing would turn on. Battery was still fully charged.

Vaseline I've read is actually a non- conductor of electricity. In the past I think it was only used to smear the top of the termnial once the connector had been fitted to stop corrosion.

[harrylime]

I usually smear some grease over my terminals. My point was about the plastic addition at the bottom of the clamp, which is where the corrosion was. I believe this can trap a small amount of water or moisture. Also, the thin nature of the clamp itself seems at odds with the over engineered nature of the car. I do wonder if the chunkier replacement will lead to more efficient charging.

[brendangeorge]

Smearing the battery post with Vaseline before fitting the clamp will help keep it from corroding.

Weird I know but that is what car electrical places did last century.

John

Hi John - good idea but done at the wrong time - I am an electrical engineer. Vas will insulate the terminals so you put it on after you have made a good connection. Clean the Battery posts and clamps as well as you can - tighten them up and then apply the Vas to keep air and moisture out. This will stop air and moisture related corrosion but not galvanic action - you will still need to make sure they stay in good condition.

I could blather on about conductors and connectors (I am an engineer) - however, if your cables are not thick enough they will not conduct well (they will heat up) - same for your connectors. How big they are and what they are made of (cables and connectors) will affect their conductivity - your Battery has to deliver a short high current burst when you crank the engine so they need to be fit for purpose.

Always take care when working around a Battery - especially with a full charge in it - make sure you don't create an inadvertent short.

Bren

[OldTrout]

When the Vaseline tip was suggested to me 25 odd years ago I was a dubious as you Bren. Vaseline is an insulator. Then again so are metal oxides and we don't bother about them when clamping metal bits together.

I checked this morning with the car electrical business that told me about the vaseline and it is still recommended practice. Smear the Battery posts and then when clamps are on smear round the outside of the clamps. Clean the Battery posts first with fine wire wool and then smear with vaseline and fit the clamps.

Us oldies may also remember little read and black felt washers that were put round the Battery posts before the clamp. They were impregnated with something to prevent corrosion. These are no longer fitted possibly because they get lost rather than being ineffective and anyway the Vaseline does all that is needed.

John