RngTrtl

I think that I am dodging voltage spikes b/c the battery is never low so there is no surge or inrush current to cause spikes; and since I am charging at the battery with the vehicle off, any spikes would be contained to the battery. hopefully

Ed MD

Mine did this all the time, I used a charger on the post in the engine compartment. The battery was always dying, I replaced it once, then again recently even though Sears stated nthing was wrong with it. I tried jumping it with my other 928, both from the front..didn't work. I had the battery box opened and tried jumping it there, but I had the ground cable off and I used the bolt...no problem..then I tried again but had placed the ground back on and tried at the battery ..no joy. The groung cable was bad. It lookede fined because it was wrapped in plastic. I had gone over all the ground contacts and freshened them. I cut the plastic off and the ground cable had oxidized at the connector where it meets the weaved cable. Apparently Sears was correct. I have replaced the ground and haven't had to charge it at all, when before I was hooking up the charger all the time. Ed M

SeanR

If you take the battery to get it tested, do not go to Sears. Take it to Autozone or some place that has the newer equipment. Sears did a "test" on mine and passed it as 'good'. 3 weeks later of trouble shooting a no start problem I pulled it out and took it to Autozone. The tool they used could actually simulate a load on the battery. Come to find out, my months worth of issues was a dead cell in my red top Optima.

Sears used the old style tester that could not simulate a load, therefor they couldn't see that the battery was bad. Not saying that all Sears are using antiquated equipment, but why waste your time.

It is a good idea to check all of your ground points and clean them. It doesn't take very long to do and at least then, if it is a bad battery, you know that the grounding points are all good and you won't have to worry about them in the near future.

Lorenfb

"I think that I am dodging voltage spikes b/c the battery is never low so there is no surge or inrush current to cause spikes; and since I am charging at the battery with the vehicle off"

Remember, the LH ECM has battery power (memory) connected to pin 4 with the key "off",
pins 9 & 35 are powered with the key "on". That's why it's best to disconnect the battery
when charging it, especially if it's totally dead even when using a trickle charger.

ew928

Which model of the Optima fits into the 928 battery box?
And did they warranty replace your Optima?

Been eyeing those redtops for a while.
Probably near my "car battery every 2 year" replacement time on the 928.

Ernest (NYC) Sick of ripping everything out to get to the battery posts to jump the car.

RngTrtl

I cannot believe that I forgot about the LH still being connected even with the key off for the memory...

UNTS1

Where is the ground cable located?

brnsrgn

Anybody find a way to fit a charging cable onto the positive lead in the engine bay, and leave it in place (like the battery tender attachment). The red plastic cap is really well or poorly designed depending upon your opinion.

JP Rodkey

This may be overkill, but on each of the 928s, I made a connector (ring type) that fits onto the under hood power post and a ground that is connected to the coil clamp bolt. Both leads protected by flex sheathing and brought to a quick disconnect plug (I don't really like the plug and may improve it later). When the car is sitting in the garage, I have the luxury of leaving the charger connected because I'm using a high-end float type charger designed specifically for long-term charging and storage of batteries. The charger is hidden in a cabinet, and I simply created a long lead to run to the connector. I have two of them, and all three cars are wired to accept the charger. Works well, and no fear of overcharging or damaging the batteries.

First pic is the charger in the cabinet, then the connector, and finally the connections.

Alan

UNTS1 - The ground cable is not surprisingly connected the the negative terminal of the battery... and on up to the chassis above.

Quite a good number of these have failed and often they become intermittent - so the flexing of it while installing a new (or removing & charging) battery can make them seem to go from bad to good - for a while.. I'm sure a bunch of batteries have been replaced because of this symptom.

Its not at all intuitive that a big old braided cable will go OC and they usually in fact still maintain a high resistance path so trouble shooting is also complicated by different behaviours under-load and wth no-load.

To the trickle charger - as JP did its easy to connect to the jump post - it all just unbolts and uses ring terminals (dissconnect the battery first!). There is actually a bolt on ground point just in front of the radiator in the same general location too. You can do as JP did or mount a small trickle only charger in the car. Mine did not fit in the battery box - so I put it near the front in the passenger side fender under the headlamp and protected by a splash shield and plastic encapsulation. Then my connection at the front of the car is a 110v plug in. This has the advantage that I can trickle charge the car anywhere (but of couse you'd need a charger for each car). Its also a lot more work of course. My socket for this is fixed in the lower grille area.

Alan

SteveG

Where can I get this 8 year battery for $80?