1997 850 sedan battery drains quickly

[dcarlson12]

As I said previously, I would get another test on the battery. Sounds like your alternator is putting out correct voltage and you are getting voltage drop in the wires.
One poster suggested it could be a short internal to the alternator. I don't know if you would pick up a current draw between the negative battery cable and the body if that were the case?
i.e. connect ammeter between the battery cable and the body. I believe you said you already did that and found on 0.01 amps or ??
I have found that a battery can 'die' very suddenly without many symptoms occurring prior to it going completely dead.
I guess you could get the alternator checked also but not sure if it can be done with it on the car. On my wife's 97 850 T5, I remember it was a pain to change the alternator. Much easy to remove battery.

[jreed]

I had problems with my aftermarket ("Ramac" brand) positive battery cable, which at the time I bought it was offered by a couple of online vendors. I wouldn't recommend that brand of cable because it eventually (after about 18 months) corroded at the crimp and had intermittent high resistance at the battery clamp end.

I wrote up a post on how the Ramac cable failed here:
https://www.matthewsvolvosite.com/forums ... =1&t=61747

I decided after my experience with the Ramac cable to build my own, which is also described in the post above. The cost of the materials was less than the cost of the Ramac.
Note that several people recommended a crimp rather than a solder connection for the clamp.

[morgant]

Well, I have replaced the positive & negative cables due to the significant corrosion that appears to extend up into the cable (no idea how far). Man, that was a ridiculously time-consuming project (I don't have large hands and I still found it difficult to work in the small amount of space to separate out & re-assemble the harness for the positive cable. I cleaned up the contact points while I was in there, naturally. sadly, still only reading 13.6V and not 14.3V.

Thanks for the heads up re-corrosion of the aftermarket positive cables, I'll keep an eye out for that.

I'll try to get the battery re-tested (for a third time; it's been difficult to get a jump and take the vehicle anywhere to test the battery, in it's current state). It has remained dead at 10.5V for the past few days while sitting out of the vehicle (naturally, it isn't really charging much in the vehicle).

I do have a replacement alternator sitting here, but am trying to decide if it's worth installing.

[morgant]

After a couple more days of back & forth With the parts store attempting to charge & test the battery (was able to get it to a 1/2 charge by running the car for an hour, then charging on 10A charger for 3hrs, though it only seemed to be taking 2A; after putting it on a 2A trickle charge overnight, as the parts store suggested, it was back down to 10.5V and dead), they finally replaced it! What a pain! In the process they also tested my starter and alternator, both of which passed.

With the new battery, which read 12.45V before installation, it's still charging at about 13.7-13.8V (so mid-range for alternator output, but acceptable), but after sitting for 24+ hrs in the vehicle with it locked & alarm armed, it's still reading 12.4V, so it holding its charge! This confirms no phantom draw, which I couldn't find anyway.

Do any of you actually see higher than 13.8V with the Bosche alternator in your 850s? If so, I'm tempted to replace the alternator (only barely, considering I have to mess with the cooling system to do the swap) since I do have a Goal Zero Yeti 400 that I use when working that I would love to charge off the vehicle, but it only does if I have the blower off in the vehicle, which isn't ideal in any season. If it actually output closer to 14.2V, it might be able to charge accessories better.

One related note, the A/C compressor clutch failed a couple years ago and broke my accessories belt, so I swapped the belt out for the shorter, non-A/C belt to bypass the seized compressor. Not sure if that'd affect alternator output (I wouldn't have thought so as the belt should be turning at the same rate)