Charge!

[nine-fiver]

Charging from the alternator has dropped off so much now that it is eating batteries in a regular basis.
About to fit a rebuilt unit that is showing 14.4V on the test bench under load, from an auto electrician.
I assume from all my research, that the voltage regulator is in the pack on the back of the alternator itself. Is there anything else in the car that can affect the voltage supplied to the battery? I have done a resistance check across the alternator supply wire, none found which is great. Calcium battery is in good condition, new in feb 2012, and tested well by the visiting RA man using his computer thingy.
Will put the reco unit on this weekend to hopefully get on top of this really irritating lingering issue...trying very hard to avoid big expense at the shop prior to Xmas.
Suggestions most welcome, of course.

[phoenix]

No, the regulation on the 9-5 is all within the alternator. It was the 9-3ss that got external control of the regulation. As long as you've ruled out any parasitic drain, a replacement alternator should do the job.

[Mark B]

Charging from the alternator has dropped off so much now that it is eating batteries in a regular basis.

I don't know if it's just me, but modern batteries just don't seem to last very long.  I wonder if the manufacturers have cheapened the specifications as people don't tend to keep cars long anymore, so the chance of people claiming on the warranty is small (doesn't apply to Saab owners of course).

Interestingly a standard Varta battery only has a 2 year warranty in Germany, but in the UK is sold with a 4 or 5 year warranty.  And the Varta Stop/Start batteries have a shorter warranty than the standard batteries, presumably because they have a hard life.

[Audax]

I don't know if it's just me, but modern batteries just don't seem to last very long.  I wonder if the manufacturers have cheapened the specifications as people don't tend to keep cars long anymore, so the chance of people claiming on the warranty is small (doesn't apply to Saab owners of course).

I found that selling genuine Saab batteries meant something like 8 year life spans and most cars got new batteries at 6-10 years old (it's a bit hard to tell really as most cars got moved on before people needed further replacements). I would also guesstimate that modern cars have way more electrical demands of a much bigger and heavier engine that needs turning over so are more likely to get abuse (with a much more evident failure mode when they get to below 50% original capacity). I can't think that I have really had to replace many batteries personally over the years.

[collywobble]

I have just replaced the original battery in my 2000 MY Vauxhall Astra 2.0 Diesel estate for the first time.  I don't think 13 years is too bad for a battery to last!

[nine-fiver]

The battery is young, and holding charge well. Computer testing results were good, so it has not been seriously damaged as far as we can tell. Interesting comment from the RA man. Calcium battery holds charge for longer but takes much longer to charge up.
The bad Alt is slowly stressing the cells and it damaged the last battery over a long period of time though. That one would not hold charge well so I am on notice to get this sorted.
So swapped that one out with the 9-3 battery. Nice to be able to do that too, just popped straight in and got me going again. The 9-3 is charging its battery at over 14.1 volts and seems to have reconditioned the damaged 9-5 battery in the last few months. Money saved there too. Reading lots of forums on this issue, it seems rather important to avoid putting a good alternator onto a flat battery, and avoiding wrecking the regulator.

[Geoff1951]

I have just replaced the original battery in my 2000 MY Vauxhall Astra 2.0 Diesel estate for the first time.  I don't think 13 years is too bad for a battery to last!

Blimey. Almost unheard of these days. I wouldn't bet on the new one lasting as long.

[nine-fiver]

I have heard, from auto parts people, that aftermarket batteries are of much poorer quality than the OEM supplied units, and certain countries get batteries that are worse than others....hmmm.

[nine-fiver]

Now have 14.2V at the battery terminals and OBD-II says 13.5 at the dash. No loss of voltage when it gets hot too, so happy with that. Cranking speed is really fast from the starter motor too. The re-co alternator has worked out well. A great pity the Twin Saabs website has been removed too. It was such a fabulous resource and will be sorely missed for this type of job.

[warmrain]

1/ Does anyone know whether there is any way you can adjust the charging voltage from the alternator on a 9-5? 

2/ Second question is: Does anyone know whether the charging voltage specification on the alternators were changed for later model years of 9-5?  Say before and after 2002?   I had an replacement alternator from Neo Bros fitted recently and its max charging voltage measured at the battery terminals is 14.1v as opposed to my previous one which (I think) gave 14.4v .  I have had some battery problems since.

I ask because the charging voltage is very relevant with respect to whether you have fitted an "old type" Antimony-Lead grid battery OR a newer Calcium-Lead grid 'low maintenance' battery OR even newer Silver-Calcium-Lead grid battery.  The newer Calcium-Lead and Silver-Calcium-Lead types need a higher voltage (viz 14.8v) to charge to 100% capacity, whereas the "old" Antimony-Lead type would attain full charge with 14.2v .

Running the 'low maintenance' Calcium battery with 14.1v will mean that the battery is never fully charged even on an extended drive, and you may therefore be constantly running at or below 50% charge level with dips into 20% or below.  Quite apart from giving you much reduced reserve capacity (you can throw the claimed AmpHr rating out the window!), constantly operating at a low level of charge means that the battery tends towards sulfation and shortened life.  I am sure this underlies some of variable battery life experiences people have had irrespective of whether they have bought a 'cheap' or a 'brand name' battery.

3/ Lastly, does anyone know whether there is some temperature compensation built into the 9-5 charging circuit to vary the charging voltage with ambient temperature, and if so, where is the temp sensor -- is it measuring air at the front of the car or under-bonnet temperature?

Thanks in advance for all your eagerly awaited answers!

PS. This link below provides some basic info on the different battery types but there is a wealth of other info on charging voltages and also estimating charge state by resting voltage (again the old tables don't apply for Calcium batteries).

http://www.centurybatteries.com.au/content/documents/battery-talk/issue-1-battery-talk-what-are-silvercalcium-batter.pdf

WR

[Audax]

1/ Does anyone know whether there is any way you can adjust the charging voltage from the alternator on a 9-5? 

It doesn't look like it, the voltage regulator is available as a spare part, if there's any tweaking you can do on that part or not I don't know but most of the 9-5 alternators are fairly standard Bosch items.

2/ Second question is: Does anyone know whether the charging voltage specification on the alternators were changed for later model years of 9-5?  Say before and after 2002?

It depends as different cars had different alternators, but talking just about the 4 cylinder petrols the early cars have a single part number from 1998-2001 for the 130 Amp alternator and then there's another for the 140 Amp alternator from 02 until the end of production (some of the part numbers cross over but I suspect they will be the same item). All the specs say that it charges "around 14V"

3/ Lastly, does anyone know whether there is some temperature compensation built into the 9-5 charging circuit to vary the charging voltage with ambient temperature, and if so, where is the temp sensor -- is it measuring air at the front of the car or under-bonnet temperature?

There is no temp sensor on the 9-5 on the charging circuit. I would suggest that Saab just specified the system once for lead acid batteries as that's what they supplied, they had some fairly stringent checks to be carried out on all batteries in storage and when delivered with new cars too. It wouldn't be worth their while to change anything once the 9-5 was released. However your information is interesting as it would lead me to a conclusion that  you don't want to fit a calcium battery onto a 9-5.

[warmrain]

Thanks Audax.
Is the voltage regulator screwed to the outside of the alternator, inside it or somewhere else in the engine bay?

My feeling is that the last few tenth's of voltage put out by the regulator and one's driving pattern may make the boundary difference between whether a Calcium battery 'sort of' works O.K. in a 9-5 or not, albeit not perfectly.  If the regulator gives you 14.4v rather than 14.0v and you drive a reasonable distance daily and it's summer --  then you never call upon the non-existent reserve capacity.  I should point out that I have actually been running a (non Saab) Calcium battery in my car for a while when I had the old alternator which gave I believe a slightly higher voltage.

However, if it is winter (when the charging voltage needs to be higher) and you only have 14.0v, your battery is also a couple of years old and you park your car out in the cold -- then this may just tip you over into a non-start situation as you are continually operating in the bottom quarter of your battery's charge range.

Interesting that Ford Focus I believe specifically specify a Calcium battery must be used because its  generator is set to a higher voltage, and presumably if operated with an old style Antimony battery would cause excessive gassing and loss of water and customer complaints.

Some other GM cars also have a higher setting.
http://www.landiss.com/battery.htm

That is why I wonder if Saab did change the voltage setting on later alternators.
[Or whether it is possible to manually alter it ...  or perhaps alter via a Tech2 setting...?]

WR

[Audax]

Is the voltage regulator screwed to the outside of the alternator, inside it or somewhere else in the engine bay?

It's under the plastic cover on the alternator. I've never known one to have to be replaced on a 9-5 as it's always seems to be the alternator bearings that fail although maybe they can get a bit out of spec without issue, I think you can replace the regulator without removing the alternator but you'd really want to have the car in the air on a ramp. It looks like the part is common to many Bosch alternators as they are sold on ebay for Saab/Volvo/Merc. However looking at those pictures it doesn't look like there's any adjustment.

That is why I wonder if Saab did change the voltage setting on later alternators.
[Or whether it is possible to manually alter it ...  or perhaps alter via a Tech2 setting...?]

I don't believe Saab ever changed it, my thoughts would be why would they bother? I would think they just rated the circuit for a lead battery and would leave it at that. There would be no benefit for them to change something and have to complete a whole bunch of paperwork related to the charging circuit just to support calcium batteries which weren't something that they sold or supplied on new cars. At that point in Saab's lifetime they were struggling with engineering resource so there would be no benefit. I note from your link that the suggestion is Bosch were somewhat hostile or in the dark to higher charging values also. Anyway, there's no way that I know of to change it (unless you can swap out the regulator) as it's a pretty much dumb circuit, it certainly can't be done with Tech-2.

The only exception to this might be on a 1.9 diesel as they have (I think) a denso alternator.

[nine-fiver]

Several weeks on Starting is good. Cranking speed is very fast. Battery is holding charge and the cell indicator is green. Weirdly, the aircon is working better than ever, making me think that it was being down-regulated by poor voltage, for the last few years, turning off altogether when the alt was expiring. Clever design feature that, but annoying in 42deg C.
Nice to expect it starts and not hope it will...
Just need to sort out the erratic boost issues now.