Battery drain and dead electrics

[ITSv40]

In 48 years of Volvo ownership I have never had a Volvo battery last less than 10 years. The last one was 16 years old before it expired.

[CNGBiFuel]

In 48 years of Volvo ownership I have never had a Volvo battery last less than 10 years. The last one was 16 years old before it expired.

Blimey, my motoring history is near as long, and I've never seen 6 years, hence 10, let be 16 is incredible. Minded that Volvo don't make batteries, and there can't be more than 3-4 world suppliers, able to meet the requirements and quantities of a car-manufacturer, I wonder who supplies Volvo?

I'm sure a some do, yet this leaves us to wonder, how many cars have an original battery after 6-8 years, let be 10-16? Then again, my neighbour is webbed-up with the Vintage Lawnmowers of Britain Association - he's taken over and become Chief Beard. Chat to him, he gets 170mpg with special carburettors.

[ITSv40]

My son did a last nut and bolt to concours restoration on his XR3i cabriolet 13 years ago. He fitted a new Motorcraft battery at the time as he wanted the battery to look correct. The battery has been connected to a CTEK intelligent monitor since new and after all these years the car starts first time even when it has been standing for a couple of months. I didn't anticipate that a branded Motorcraft battery would be a particularly good quality but it has stood the test of time.

[Luxobarge]

I don't think I've ever had a battery last as little as 7 years, apart from the Volvo's current Lion battery, which is rubbish and will permanently die soon.
My record is the Bosch in my MG Midget, replaced last summer after 25 years. The 091 in my Jag XK8 lasted a good 15 years or so too.

[CNGBiFuel]

Don't suppose a restored XR3/Midget etc has done too many miles since, hence its cosseted battery. Seems that might be the trick, left on float-charge with a decent supply, and seldom used I can see how to do this. Hardly typical use, but it'll work.

Whereas, chalk & cheese, If they're deep-discharged, once-too-often, and cycled in use every day in cold, and high-load conditions. In my case, pre-COVID 20+K a year, none of this is ever good.

They don't last, and I suspect it's not brand dependent. Batteries in my hands see a hard life, hence give me a 5 year warranty and I'll call upon it. Maybe the other extreme, and not typical either? Our Midget /XR3, won't see too many battery-crushing dead-short February cold-starts.

i suspect we're using the smae batteries, the greater difference is how they're treated.

I suspect there's not much in 'quality' between a 3 or 5 year battery. It's purely that manufacturers do their numbers, and have worked out that the 'backsy' element to a 5 year battery is profitable for the price premium - the number of claims actually made on a 5 year, still leaves a margin to make the offer profitable.

[2valves]

Can add a theory to this, I had a similar issue with my 850 years ago. Check engine light came on... I ignored it... then started to get flat batteries after a few days, eventually this killed the battery. But I noticed that when you disconnect the battery with a hot engine the check engine light goes off until you next start from cold. Turns out the SAS / Smog pump system was at fault. Relay had corroded causing the pump not to run, so instead of air going into the exhaust, exhaust flows into the pump, valve also sticks open causing this to happen all the time not just at a cold start. Exhaust then condenses in the pump killing the pump and in my case causing the battery drain. The condensed exhaust was then sometimes blown back into the air filter box leaving a brown stain on the filter. Best method is to check the fuses for a draw, but this might help. Check engine light disappears with a hot engine battery disconnect as the pump only operates (or not) briefly when the engine starts from cold.

[stevepcar]

Originally Posted by 2valves

Can add a theory to this, I had a similar issue with my 850 years ago. Check engine light came on... I ignored it... then started to get flat batteries after a few days, eventually this killed the battery. But I noticed that when you disconnect the battery with a hot engine the check engine light goes off until you next start from cold. Turns out the SAS / Smog pump system was at fault. Relay had corroded causing the pump not to run, so instead of air going into the exhaust, exhaust flows into the pump, valve also sticks open causing this to happen all the time not just at a cold start. Exhaust then condenses in the pump killing the pump and in my case causing the battery drain. The condensed exhaust was then sometimes blown back into the air filter box leaving a brown stain on the filter. Best method is to check the fuses for a draw, but this might help. Check engine light disappears with a hot engine battery disconnect as the pump only operates (or not) briefly when the engine starts from cold.

I have a 95 850 2.0 litre that has the SAS/Air pump, it has failed as they seem to do & throws up a EML. I have carried out the mod to the ECU that involves soldering a diode into the circuit which effectively cuts the Air pump itself out of the system. This has not stopped the EML from coming on. So it seems that one of the other components in the SAS is faulty. The relay seems to be another weak point. Its all to do with where the components are fitted in the way of water and dirt, causing corrosion. The SAS is not usually fitted to vehicles in this country, but is quite common in the US. They have numerous posts on deleting it, one even says that you can get rid of all the associated components, but I have not investigated this. Has anybody elese found a way of removing this nuisance?

[2valves]

Originally Posted by stevepcar

I have a 95 850 2.0 litre that has the SAS/Air pump, it has failed as they seem to do & throws up a EML. I have carried out the mod to the ECU that involves soldering a diode into the circuit which effectively cuts the Air pump itself out of the system. This has not stopped the EML from coming on. So it seems that one of the other components in the SAS is faulty. The relay seems to be another weak point. Its all to do with where the components are fitted in the way of water and dirt, causing corrosion. The SAS is not usually fitted to vehicles in this country, but is quite common in the US. They have numerous posts on deleting it, one even says that you can get rid of all the associated components, but I have not investigated this. Has anybody elese found a way of removing this nuisance?

I don't have any experience of conducting this modification myself, I repaired my system using as you mentioned several posts from across the pond on the subject. Assuming that you've got the diode in correctly and you have the same code as before that simply will not reset, try unplugging the relay and motor, clear the codes out again and see if the diode alone keeps the computer happy. Only other thought I have is to ask around and see if anyone can confirm the mod is known to work on a 2.0 especially if it's a 10V engine. Don't think the 2.0 in any form was sold outside of Europe, so the 2.0 with the smog pump is likely quite rare.

[Yog Sothoth]

I eventually solved this problem as well. Or had it solved, anyroad.
Turned out the alarm system has a very powerful alarm sounder, which has its own battery supply, something I've never encountered before.
Being old NiCd batteries, they had packed in and were pulling a current from the main battery. The batteries are not readily available (main dealer maybe), so I just had the dead batteries and sounder removed and haven't had a problem since.

[4x4]

EDIT: Deleted post

Just noticed this is for the V70 so different system...