Battery Questions

Submitted: Wednesday, Jun 10, 2009 at 17:30
ThreadID: 69689 Views:1757 Replies:4 FollowUps:2
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Hi ladies & gents,
I have a 2005 LC100 V8 which still has the original EOM battery. I A couple of years ago I installed a 2nd battery (Exide N70 Extreme) using a Surepower management system.
2 questions please.
1st- Every now and then the EOM battery seems to go flat way too easily when leaving a door ajar or the radio on for just a couple of hours. I have had the battery tested by the local auto sparky and he says that everything is ok ie: it is being charged at the correct voltage and it holds up well under load testing. It always charges quickly if it does get flattened in the above way. Apart from this I have had no problems with this battery. Any ideas why it would be going flat so easily - I thought about it dropping a cell but this was dismissed by the auto sparky.
2nd question - I am continually getting corrosive acid on the negative terminal of the second battery. Other terminals on both batteries have no problems. Any ideas on what could be causing this? and how to stop it.
Many thanks
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Reply By: tim_c - Wednesday, Jun 10, 2009 at 18:23

Wednesday, Jun 10, 2009 at 18:23
If you do lots of short runs (particularly in the night time) your main battery may never get fully recharged after starting the engine. Making sure you do a longer drive every so often (or plugging into a charger if the car is used infrequently) should give the battery a decent top up.

There is a technical reason why you get a corrosive buildup on the battery terminal (which I don't know well enough to explain). Clean it off as best you can with a wire brush, then spray the terminal with some corrosion inhibitor which you can get from an auto-sparky (this should have been done when the battery was installed).
AnswerID: 369363

Follow Up By: CraigB - Thursday, Jun 11, 2009 at 15:25

Thursday, Jun 11, 2009 at 15:25
Hi Tim,
I think you have hit the nail on the head.
I'm always doing very short runs. I guess that also explains why when I do go away I never have a problem (because the battery has been fully charged on the long drive). Many thanks
Craig B
FollowupID: 636930

Reply By: MEMBER - Darian (SA) - Wednesday, Jun 10, 2009 at 18:49

Wednesday, Jun 10, 2009 at 18:49
Is it not highly likely that after 4 years, that original factory battery is nearing the end of it's service life ? Without being rude to the local auto sparky, his readings may not tell the whole story. BTW...... just replaced the TWO original batteries in my 05 GXL TD... all was fine until the cold weather turned up a few weeks back..... one of them was struggling in the mornings and dragging the other down with it. $440 later (gulp) for two shiny new GSYuasa Power Series Ultra @ 545CCA each and it spins like a top on frosty mornings.
AnswerID: 369371

Reply By: Sand Man (SA) - Wednesday, Jun 10, 2009 at 19:04

Wednesday, Jun 10, 2009 at 19:04
You should be able to eliminate the corrosive deposit.

First of all, chuck a solution of bi-carb of soda on the terminals to neutralise the acid.

Then check that the terminal clamp is clean. If necessary this can best be done with a cheap wire brush terminal cleaner available at any auto shop.

At the same time you buy the terminal cleaner, also ask for a set of felt disks (red and green) and place one each over the battery post before reinstalling the cable clamps. The felt disks will eliminate further build up of the acid deposits.
I have not found it necessary to add anything else to the disks.


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AnswerID: 369378

Follow Up By: CraigB - Thursday, Jun 11, 2009 at 15:30

Thursday, Jun 11, 2009 at 15:30
I reckon some corrosion inhibitor on the terminals might be the way to go as stated above.
I think my numerous very short drives is not allowing the battery to fully charge. Thanks for the reply.
FollowupID: 636932

Reply By: Robnicko - Thursday, Jun 11, 2009 at 11:35

Thursday, Jun 11, 2009 at 11:35
Sounds like the OEM battery is nearing it's end of life.
My original one in my 80 Series worked fine for about 8 years and one night just refused to crank th engine over. I jumped it off the second battery and then after about an hour of driving it seemed fine however when it did it again the next morning I thought best to get a new one.

Is it a maintenance free OEM? you can always remove the sticker on top and top up the fluid, however 4 years old + turning a V8 most likely on it's way out.

Corrosion on the second batt could also be overfilling of the cells.

Just a theory but if the starting batt is going flat, when you jump it and the alternator kicks in it will be working overtime till the battery is fully charged which in turn is also charging the 2nd battery and possibly boiling it over through the vent caps. Start the engine and see if bubbles are coming through the vent caps and also check the fluid level, should be just above the plates.

AnswerID: 369484

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