Is there any benefit to a battery charger?
Discussion
Might seem like a stupid question but I can count on one hand how many times I've used one in my life.
Backstory: Cleaned the car interior on Sunday so the interior lights were on, then pumped a few tyres up inc the MTB and car with the engine off. Went to bed. Next day the car warned me the battery was low but still fired up fine, it just turned the radio off for me to save electricity.
On the way to work I turn the sidelights on (as thats the only way to turn the headlights off while driving) again to save some juice. Park up, forget to turn the sidelights off, car completely dead when I come out of work.
Recovery guy shows up, batt is on 7 volts, hooks up a booster pack and it fires right up and behaves fine for me 3 mile commute home.
I think the battery itself is fine, it's just that it does very short journeys with one one hour trip each way once a week.
I just started the car now to check and once again it fired up just fine, despite being stone cold dead just a few hours ago.
So I can either:
A. Get a new battery for £90ish
B. Get a charger for £20 and leave it in the house
C. Get a booster jump pack
D. Take it for a long drive and forget about the above. It survived just fine over winter doing that 3 mile commute, spring/summer will be fine for it.
So I'm wondering what situation you'd ever need a charger for a daily driver Vs jump leads or a booster pack?
Backstory: Cleaned the car interior on Sunday so the interior lights were on, then pumped a few tyres up inc the MTB and car with the engine off. Went to bed. Next day the car warned me the battery was low but still fired up fine, it just turned the radio off for me to save electricity.
On the way to work I turn the sidelights on (as thats the only way to turn the headlights off while driving) again to save some juice. Park up, forget to turn the sidelights off, car completely dead when I come out of work.
Recovery guy shows up, batt is on 7 volts, hooks up a booster pack and it fires right up and behaves fine for me 3 mile commute home.
I think the battery itself is fine, it's just that it does very short journeys with one one hour trip each way once a week.
I just started the car now to check and once again it fired up just fine, despite being stone cold dead just a few hours ago.
So I can either:
A. Get a new battery for £90ish
B. Get a charger for £20 and leave it in the house
C. Get a booster jump pack
D. Take it for a long drive and forget about the above. It survived just fine over winter doing that 3 mile commute, spring/summer will be fine for it.
So I'm wondering what situation you'd ever need a charger for a daily driver Vs jump leads or a booster pack?
Modern cars need decent runing time to recharge the battery. You'll probably just about get away with it with weekly one hour journey as long as there aren't too many very short duration journeys inbetween.
I find that once a battery has gone flat they never seem the same again - might be fine through this summer, then give up the ghost when it gets colder next winter.
I find that once a battery has gone flat they never seem the same again - might be fine through this summer, then give up the ghost when it gets colder next winter.
FTR 7v is flatter than a flat thing with an elephant sat on its head obviously.
That battery is exceedingly unlikely to be long for this world, they very rarely recover from such a beating, no matter how much you charge them up.
I have one & actually use it pretty regularly knowing what I know about batteries.
If either of our cars isn't used for more that a week I will put it on charge for a few hours.
That battery is exceedingly unlikely to be long for this world, they very rarely recover from such a beating, no matter how much you charge them up.
I have one & actually use it pretty regularly knowing what I know about batteries.
If either of our cars isn't used for more that a week I will put it on charge for a few hours.
I’m not sure cars made in the last few years use the high cold charge approach. It makes mechanical sense to load a cold engine to aid warm up but it affects mpg and therefore CO2 output on the tax test.
Subaru used to hold off charging until the engines had warmed up to aid cold start mpg. As a result owners who did lots of very short journeys could end up with a flat battery. My old mk1 Focus on the other hand used to provide a high charge rate when cold.
Subaru used to hold off charging until the engines had warmed up to aid cold start mpg. As a result owners who did lots of very short journeys could end up with a flat battery. My old mk1 Focus on the other hand used to provide a high charge rate when cold.
Put simply: yes.
A battery takes about 12-24 hours to properly recharge from flat. So a decent battery charger can fully recharge a flat battery and it can live on for a meaningful time after. Running the car, even for an hour, is a very expensive inefficient way to charge a battery and won't fully charge it. Its the time left while discharged which is bad for a battery (amongst other things, like depth of discharge).
A battery takes about 12-24 hours to properly recharge from flat. So a decent battery charger can fully recharge a flat battery and it can live on for a meaningful time after. Running the car, even for an hour, is a very expensive inefficient way to charge a battery and won't fully charge it. Its the time left while discharged which is bad for a battery (amongst other things, like depth of discharge).
"very long", "fine" and "slowly" are qualitative. You can measure a battery state of health (and state of charge) and get a quantitative result. It won't say how long into the future it will last, but it will say if its healthy or not. I've bought cars with fully discharged battery, recharged it and its been "fine".
Have you got auto-lights, or is there another reason the headlights come on all the time?
If it's auto-lights, just leave them alone and let the alternator charge the battery as you drive...you won't risk leaving your sidelights on then (or forget to put your headlights on when you do need them).
If it's auto-lights, just leave them alone and let the alternator charge the battery as you drive...you won't risk leaving your sidelights on then (or forget to put your headlights on when you do need them).
mmm-five said:
Have you got auto-lights, or is there another reason the headlights come on all the time?
If it's auto-lights, just leave them alone and let the alternator charge the battery as you drive...you won't risk leaving your sidelights on then (or forget to put your headlights on when you do need them).
It's a Volvo with the dumbest headlight system I've ever encountered. You have 3 options:If it's auto-lights, just leave them alone and let the alternator charge the battery as you drive...you won't risk leaving your sidelights on then (or forget to put your headlights on when you do need them).
One is manual dip beam, in which you can't toggle high beam (only flash). Dip are permanently on and turn off with ignition
Two is sidelights/parking lights only. With this activated the dip beam turns off and only the LED strip sidelights turn on. These stay on with the key out and ignition off with only a tiny dim green LED by the switch to let you know they're on.
Three is 'auto lights'. Again, dip beam are ALWAYS on regardless of time of day, as well as auto levelling and corner assist (bends the light beam in a turn). All this mode does is allow you to keep HIGH beam on once the car knows it's dark or heavy rain.
It's a switch I rarely if ever touch. Just on that one day I thought 'lets conserve some energy and force side lights only and turn dip beam off', only to forget to switch it back, because again, I never touch it. Lesson learned.
I've heard on the forums you can get a Volvo dealer to code auto lights to work the correct way. I.e. side light/DRLs during day time then it auto toggles dip beam on in low light. It already has the sensor and I believe it works this way in other countries. But for the UK they coded it so that the dip beam work as DRLs AS WELL as the side lights for some unknown reason. Just shortens the life of the HID bulbs and wastes energy if you ask me. Also makes you look a bit of a throbber with dip beam on all the time even in the peak of summer.
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