Well, over the weekend the car died; at least it was while at home. Got it started with a jump box, but it died again a day later and not even the jump box helped. So, walked over and bought a replacement battery, the car starts fine.

But I really don't want to trust it out and about with my wife driving, even locally. So, I made an appointment with a neighborhood independent shop, and will take it (shoot, not for a week!) Anyway, can I presume that they can do a diagnostic on the charging system simply by plugging in to the OBD port? Or is the analysis more in-depth than that. Automotive electrics are a black art to me, I have no clue.

Anyway, the 1st battery died after about 7.5 years, as did this one. Nice data point but not the same as proof that the rest of the charging system is OK.

 

Pretty much any AutoZone type place can check the charging system for you. It involves connecting a diagnostic tool to the charging system (usually the battery posts) and measuring the voltage.

 

You can easily diy this.

Just go to harbor freight, buy cheap digital voltmeter. Less than $10.

With car off, measure battery voltage. Oneprobe on each battery terminal. Should be around 12.6v. Doesn't take much to make battery too dead to start, like 12.3v and below usually will prevent startup.

Now to test what you're actually interested in, charging. Start engine, take same measurement, at battery terminals. Healthy charging system should be around 14.5v. Anything below about 13.6v no bueno.

If you mix up red and black, + & -, meter simply reads negative numbers. But numbers still valid, so no worries. Use either way.

You're literally just putting one meter probe on each battery terminal.

Hardest part of this is setting up meter to read DC volts.

Its just looking for the V, and setting to that (might also be a DC vs AC option, which might show up as either a straight dotted line (DC) or sine wave line (AC)). Use DC.

Might also be two places to plug in probe on meter. Again, use the one with the V.

Basically, if you test battery woth engine off and its not reading like 12 something, you know you have meter setup wrong.

 

It is not unheard of to fry your alternator rectifier when jumpstarting the S2000. If that occurs you may notice flickering lights on the dash.

 

Ouch. I guess I should at least take it for a short drive and look for that. Reading online, the rectifier is a discrete part, but I'm reading a lot of range in the cost for the replacement. I do know my wife drove the car a couple of times in the 24hr after the 1st jump-box start, and the time it died and we replaced the battery, she did NOT mention flickering dash display. (Hmm, there does not seem to be a crossed-fingers emoji)

 

I've jumped mine plenty of times with a battery pack owing to the fact I don't drive it a huge amount and the alarm kills the batteries quite quickly.

No issues with the alternator as a byproduct, so you'd be quite unlucky.

 

I am drawing on memory from warnings by Billman and associated threads with that issue.

 

Plenty have had the dash flickering issue after jumping. I think it is more of an issue of jumping with a severely depleted battery, which adds stress on the charging system after as it tries to finish charging the battery, which then damages the rectifier. Always better to charge up a severely depleted battery first and then start vs just jumping off directly and letting the cars system take the load of charging the battery.

 

Well, GOOD news? Had no choice, drove the car a bit, no flickering dash lights.

We had the battery issues on the day I was supposed to pick up the Boxster from a dealer 30 miles away after service, had a crisis getting there (Boxster is fine, now). OK,. wife drove the Boxster to work while the S2000 sits, and I get a call "got a message, my key fob is low battery, car won't start!". OK, she works 2-1/4 miles away, drove the S2000 due to few options, dropped off spare key and she got home. S2000 performed fine, no flickering lights. Perhaps I dodged a bullet.

Sheesh, what's next?

New rule: put a computer calendar reminder in, change fob batteries annually regardless of age, cheap insurance!

 

Not sure what the key fob battery has to do with starting a S2000 or did I misread?

-- Chuck