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Volvo V40 Battery Problems

Hi guys, I just purchased a 1998 Volvo V40 for about as much money as I could afford. The battery on it however wasn’t the correct battery and wouldn’t hold a charge. I managed to start it just once from the battery and that was only immediately after turning the engine off. I had someone in the car part shop put a tester on the battery as my charger didn’t seem to charge it and it turned out the battery was faulty. I replaced the battery with the correct one and all was fine for a little while, however after I left the car for about six hours the battery was dead again. When I connect my charger to the battery the red light is supposed to stay on but it just shuts off like it did with the old battery. Any idea what could be causing this as I think my car may just have destroyed a brand new battery.

Your new battery has not been destroyed, it may be discharged but you need to use a volt meter to determine if the battery has been discharged. The first step is to measure the battery voltage, next the voltage at the starter.

I suggest you take the battery to a place that check the condition of it. As new as it is it should be in good shape but if the charging system is over charging it then it could be damaged. You may have a parasitic drain on the battery while the car is parked and that drained the battery. Checking the current drain on the battery would be a good thing to do along with having a load test done on the charging system of the vehicle. These are things any good shop could do for you.

You may have an problem with your battery charger if it keeps reacting like it has with other batteries.

After my battery went dead, I bought a couple of these plug in devices. They don’t do much but will tell you your battery voltage and the charging voltage when you plug it in.

Good ideas above. Besides those, another guess, you could have an alternator problem . Try disconnecting the battery from the car and charging the battery, see if the red light on the battery charger problem disappears when the car’s wiring is out of the loop. If so, that could indicate a problem with the alternator, like a shorted diode. One test: If you have a volt meter, check to make sure the battery voltage is in the 13.5 to 15.5 volt range when the engine is running and the alternator spinning; it should read on the higher end of that range when first starting the engine.

##Update## I took the battery back to where I bought it, they charged it and tested it and said it’s fine. So I tested the charge on and it showed 12.69v. Then I connected it to the car and tested it again, 12.24v. Disconnected the CD autochanger which I doubt worked anyway and it went up to 12.51v. With the engine running it went up to 13.98v and immediately after shutting off the engine it dropped back down to 12.75v. So I tested it again after one hour - 12.6v, after two hours - 12.57v and after three hours - 12.54v. I’m no expert but it it’s only losing 0.03v per hour then it should hopefully have enough power to start in the morning and get me to work.

Thanks to all for the responses.

The slow drop in battery voltage from 12.75 to 12.5 volts after turning the engine off is probably normal. As is the 14 volts with the engine running. My Corolla does that same thing, same numbers in fact. On the other hand, when you connected a fully charged battery measuring 12.7 volts to the car and the voltage immediately dropped to 12.25 volt, that isn’t normal. It sounds like you’ve isolated the problem to the CD player. Good call. Hope you have it resolved now. If not, there are fairly easy to do tests to figure out which circuit(s) are draining the battery.

Faulty CD player/changers are a pretty common source of trouble for battery current draws. I suspect you have found the problem and are good to go. Good job. In case you do need more help…technicians are standing by!

So the battery was dead again this morning… any technicians with ideas? I’m probably going to disconnect the battery while the car is not in use but that’s a less than ideal solution.

Disconnect it, charge it, and see if it holds a charge. Auto batteries do not respond well to a complete discharge, they suffer damage. Do this a few times, and the battery may be toast.

All of the above is pretty much true… Batts hate being discharged deeply…that where Deep cycle batts come in…but are not needed when things on a car work correctly.

Sounds to me like your alternator has more than likely crapped out on you. Easy to test… just disconnect the HOT wire that runs to it. Protect the end so it cant ground out and then Recharge your battery…and see if the charge stays put. If it does…you just found the problem. There are other ways to test this out as well. But the alternator is the primary suspect. You can also feel the alternator while the car is sitting and engine cold…if the alt is warm to the touch…you found it again.

When you go to recharge your batt again…disconnect both leads that go to the car…so the charger is isolated onto the battery alone. If your batt didnt crap out from being so discharged…it will survive and be recharged. Just be sure to isolate it. Do the other things I suggested if you want to find the culprit. I have to do these things on a semi daily basis…the usual culprit? The Alternator…or more specifically…the voltage regulator that shorts out and is internal to the Alt and or the windings of the armature…but this goes beyond the scope of this discussion…basically all you need to know is Suspect Numero Uno is the Alternator. Barring anything else obviously consuming power.

If its not the alternator…you will need to go thru the subsystem batt drain procedure at the fuse box to locate the system draining the batt. The two most common by FAR…are the Alternator number 1 and in close second…factory Amplifiers that don’t shut off.

My money is on a shorted out Alternator…happens ALL the time.

Then again…if that CD changer did the trick…ignore the above steps…if it doesnt…get right back to them… LOL


You need to figure out why the battery is discharging. I think you said you have a new battery, so the battery must not be the reason. Most likely some kind of phantom current drain. With everything off, car parked, key out of the car, like it would be leaving it overnight, battery fully charged, the battery phantom current shouldn’t be much more than 100 mA. 150 mA tops. On my Corolla it is around 30 mA, but on newer cars it tends to be more b/c of all the electronic gadgets.

Suggest to follow your car’s service manual for how to do it on your Volvo, as it varies car to car, but the way I make that measurement on my Corolla is disconnect the battery negative cable from the post, and place an amp meter in line between the battery negative post and the battery negative cable. Make sure everything is turned off, key out of ignition, all doors closed, dome light off, etc, before starting this experiment. If what I just said seems like Greek, best to let a mechanic do it for you.

One thing to worry about doing this, if you are the worrying type, if you have a big current drain going on there you might burn out your amp meter doing this. So best to start with the highest amp range your meter supports, at least 10 amps, and just briefly tap the meter into the circuit to see what you’re looking at current-wise, before trying to get an exact reading.

It’s always a good idea to wear safety protection for your eyes when working with batteries.

The easiest way to check this kind of trouble out is to monitor the current draw on the battery which requires a current meter to perform the test. I suspect you don’t have one on hand which is part of the reason I previously suggested you take the vehicle to a shop and have not only a load test done on the charging system but also a check for an excessive current drain on the battery. It shouldn’t cost you very much to have that work done and the results of the testing will tell you what servicing needs to be done to solve this issue.

Think his CD changer was fount to be the culprit…


HB, the OP later stated that the battery went dead again after he disconnected the CD changer.

OH…GOOD… Then refer back to my post and let us know… LOL


OK it’s weekend again and I get to play under the hood some more. I’ve disconnected the battery and put my new multi-meter in series to measure the current. Disconnecting the alternator made no difference so I tried pulling all the fuses one by one. None of those made any difference either so I’m starting to suspect it’s something intermittent. I’ve left it now with the alternator disconnected and the battery connected to see if the battery keeps its charge this time as I don['t know what else to test.

But what is the meter reading? Did it change when you disconnected various items?

with everything disconnected, the ammeter won’t read anything. I assume you are now measuring voltage?

Whoa, wait disconnecting the Alternators MAIN Hot wire did nothing? What precisely did you do? What was the test you performed that involved disconnecting the Alternator ? What tools did you use? How did you interpret the results?

I listed the instructions as close as I could possibly recall and do not think I left anything out. Can you please detail the specifics of YOUR test? Its kind of easy to forget what means what in this case. Ive had people tell me they performed what I asked…and in reality…they did not.

Please outline your test and your interpretation of each result before we discount THE Most Common culprit of battery drain (BAR NONE) and begin to move on elsewhere in the search.

If it is NOT the alternator…that is fine…we have other things to look into, but please tell me precisely what you did when you said you disconnected it, you need tools to do this correctly, you cannot simply unplug a plug using your fingers…that is not the correct connection, which is yet another reason why I am asking for a play by play on this. Its important that your judgement of the criteria is not off in any way. I solve these problems semi-daily…many of the guys here are more than familiar with this too… So please detail for us if you will…


I disconnected the negative wire from the battery and put the red probe on the negative battery terminal and the black probe on the negative wire. This gave me a reading of 85.5mA. This didn’t change when I disconnected the fat wire with the nut on it (I’m assuming this is the one you’re referring to as hot). I then tried pulling out one fuse at a time but none of that made any difference to the current. The only time the reading changed was when I put the ignition on which put it up to something like (I don’t remember exactly) 96mA.