car battery charging level?

ShiWarrior · 17 Jan 2019 at 20:05

Is it at all possible to check the level of charge the battery is getting when the car is running from the 12V socket inside the car ? (or obd port))

for example, im driving to and from home directly so the mileage is low, is it possible to check what the cars battery level is ?

I've put a volt reading checker into the cig lighter and i can see that when the car is running the voltage is higher than when the engine is off (because its charging) but what level is the battery at i'd like to know
i.e. 80% charged?
90% charged ?

is there a tool or lead that will do this?

andy_mk3 · 17 Jan 2019 at 20:11

When the car is running, the voltage will always be higher while the alternator is running which generally outputs 13.5-14.5 volts. Just measuring the battery voltage, a fully charged battery will be around 12.8volts. 12volts is about the lowest you want it. Leaving 12.4volts as about 50% charged.

This isn't an exact science but a rough indication at least. It does take a good few hours for the voltage to settle after charging too.

Also, there are dedicated tools for testing batteries which do vary in price. They can measure the capacity of the battery's cranking amps.

ShiWarrior · 17 Jan 2019 at 20:12

andy_mk3 said:
It does take a good few hours for the voltage to settle after charging too.

oh right, i didn't really know that
thanks

Lordgrayone · 17 Jan 2019 at 20:38

How short is short?

ShiWarrior · 17 Jan 2019 at 20:39

Lordgrayone said:
How short is short?

6 miles each way
+ dashcam sapping power, i run the car for 30 mins in the morning to try and re charge it a bit

andy_mk3 · 17 Jan 2019 at 20:43

Be far better to run a trickle charger. Running it at idle is doing more harm than good.

Lordgrayone · 17 Jan 2019 at 20:49

That is short for giving it a proper charge and as said above giving it a charge on idle will be putting a minimal amount back in to the battery so it's not ideal.

Pretty sure ocuk don't sells these so might be of use

https://www.amazon.co.uk/dp/B00ZETX...=aud-544645955450:pla-530014048936&th=1&psc=1

Edited as meant. Not ideal to idle

ShiWarrior · 17 Jan 2019 at 21:43

Lordgrayone said:
That is short for giving it a proper charge and as said above giving it a charge on idle will be putting a minimal amount back in to the battery so it ideal.

Pretty sure ocuk don't sells these so might be of use

https://www.amazon.co.uk/dp/B00ZETX...=aud-544645955450:pla-530014048936&th=1&psc=1

interesting, thanks for the link

Tee Hee Johnson · 17 Jan 2019 at 22:47

My Fiesta, using FORScan and Bluetooth, can show a statistic called Battery SOC %, which is State of Charge.

I've noticed when low 70% and below, stop start is disabled.

Its usually kicking about 85-90% after a nice long run. (Aberdeen a few weeks ago, for example)

Perhaps your car has similar.

ShiWarrior · 18 Jan 2019 at 09:07

I've heard of FORscan , plugs into the OBD port ?

I've seen a display that shows state of charge (used the Amazon link above to see them) which should do the trick, rather have that so I can glance at at now and again without getting my phone out my pocket all the time

ShiWarrior · 18 Jan 2019 at 17:49

would something like this work ?
https://www.amazon.co.uk/Multifunct...YXQE45QKWT6&psc=1&refRID=SDHM4ZNAQYXQE45QKWT6

Howard · 19 Jan 2019 at 08:13

I can't see 6 miles causing any issues. My old commute was 5.5, and it would take between 20 and 35 minutes. Never had any issues with battery charge in the three years that I was doing the commute.

ShiWarrior · 19 Jan 2019 at 08:32

My dashcam on parking mode drains it

Takes me 10 minutes to get to work as there's no vehicles about at 5am

andy_mk3 · 19 Jan 2019 at 10:22

ShiWarrior said:
My dashcam on parking mode drains it

Takes me 10 minutes to get to work as there's no vehicles about at 5am

Shouldn't affect your battery, unless your dashcam charger is wired up to a permanent live rather than an ignition live. But in that case it would always draw power, not just when the dashcam powers up.

robj20 · 19 Jan 2019 at 10:54

Depends on the car, on mine you can plug your laptop in and see the battery stats including charge percentage.

phil-k · 19 Jan 2019 at 11:26

II did see a video where someone with one of the modern stop start cars had a voltage meter plugged into his cigarette lighter socket, it showed that the alternator was only charging the battery sometimes.
I am planning to get a 2014 Focus which has this system and Varta battery and I only do very short trips with the car parked for a couple of days at a time and am worried about the battery draining.
I was thinking of getting one of those solar panels to just keep the charge up, but some people say they are not a good thing with a Varta battery for some reason, also that you cannot use jump leads if it does go flat, anyone had any experience of this
Thanks

Dangerous Dave · 19 Jan 2019 at 11:51

Did you not have a post sometime ago about this problem ? did you get a new battery ? If it is starting to cost you money replacing the battery or the fuel leaving the car idling for 30 minutes every morning taking cost to benefits into account it may be better to just turn off/unplug the dashcam when the car is parked ?

andy_mk3 · 19 Jan 2019 at 14:16

phil-k said:
II did see a video where someone with one of the modern stop start cars had a voltage meter plugged into his cigarette lighter socket, it showed that the alternator was only charging the battery sometimes.
I am planning to get a 2014 Focus which has this system and Varta battery and I only do very short trips with the car parked for a couple of days at a time and am worried about the battery draining.
I was thinking of getting one of those solar panels to just keep the charge up, but some people say they are not a good thing with a Varta battery for some reason, also that you cannot use jump leads if it does go flat, anyone had any experience of this
Thanks

It has smart charge which can change the alternator output as required. With a low battery charge it will still charge as normal, or sometimes even quicker with a higher than normal voltage. It only reduces the output for economy when cruising really.

ShiWarrior · 19 Jan 2019 at 17:53

Dangerous Dave said:
Did you not have a post sometime ago about this problem ? did you get a new battery ? If it is starting to cost you money replacing the battery or the fuel leaving the car idling for 30 minutes every morning taking cost to benefits into account it may be better to just turn off/unplug the dashcam when the car is parked ?

yeah i posted something last year

in this thread i just wanted to get a cheap device than i can hook up somehow to see what percentage the battery is out whilst driving, so i can see it charging up, so like to know if i need to give it a run on some days

battery is under warranty and still starts perfectly fine , shop wont change it as its not faulty

thanks

Dangerous Dave · 19 Jan 2019 at 18:31

You won't be able to tell the charge level when driving as the alternator will be outputting 14v+ when the engine is running, it's the resting voltage you need to check to get an estimate on it's charge level and in the other thread the voltage was 12.1v even after being charged which indicates the battery is at approx 50% of capacity. Have you had the battery load tested ? I expect it would fail and be replaced under warranty.

What car do you have ? If it's a Ford some need a silver calcium of battery for the smart charging system if a normal battery is put in it can damage and shorten the life of the battery.

Do you have a particular reason why parking mode on the dashcam is so important ? You could run the dashcam off a large USB battery pack buy two and alternate with charging one in the house/office. It could also get topped up when the car is running.