Battery tester through cigarette lighter

[Newbie47]

Has anyone used/would recommend a Battery tester through the cigarette lighter to monitor their Battery?

Thanks in advance 

[TonyHSD]

Hi, 

I have in mind this one. Haven tested myself yet but I got power banks from the same company and they seems of higher quality. 👍

https://www.amazon.co.uk/dp/B093V384KK?ref_=cm_sw_r_cp_ud_dp_HST2DBP2NR9Q6CNZNVXP

[Hornet3D]

If you need to use the socket there is this

OTIUM USB Car Charger Cigarette Lighter Splitter, USB C Power Socket adapter with 2 Separate Switch Sockets(12V/24V) 80W Replaceable 7.5A Fuse Dual 2.4A USB Adapter one Type-C Port Voltage Display: Amazon.co.uk: Electronics & Photo

[Cyker]

I used to have a cigarette socket dongle that had USB ports and showed the 12v voltage, similar to the one TonyHSD posted, but made the mistake of lending it to a mate...

I will say it wasn't so great in the Mk4 Yaris as the socket is recessed in the centre console tray thing and it makes the voltage display hard to read; One that sticks out further or has a fly-lead might be more practical.

[TonyHSD]

I just ordered one iniu for myself and will test it tomorrow night. Will share later if any good. 

[Guest]

I did have an item similar to that in the link. However, for a tidier alternative I fitted the small diplay and u.s.b. outlets shown in the pictures.

It is fitted in a once blanked spare switch "hole" to the left of the speedometer cluster. It also leaves the 12v outlet free for something else, if necessary.

Not as easy as plugging in something though! It does require an ignition switched supply and earth. Cables are provided along with an inline fuse.

[Newbie47]

On 5/11/2022 at 7:48 PM, TonyHSD said:

I just ordered one iniu for myself and will test it tomorrow night. Will share later if any good. 

Hi TonyHSD - did you end up getting the iniu?

[TonyHSD]

1 hour ago, Newbie47 said:

Hi TonyHSD - did you end up getting the iniu?

Hi, 

yes I had one. The charger is good and works fine, shows voltage correct too. Unfortunately it did not stayed in place on my car and I had send it back. I don’t know why but in my Auris any car charger different than Tom Tom one  pops out easily. Shame really, because  the charger is good. You can try if you like it. Here some pictures. 

[Newbie47]

58 minutes ago, TonyHSD said:

Hi, 

yes I had one. The charger is good and works fine, shows voltage correct too. Unfortunately it did not stayed in place on my car and I had send it back. I don’t know why but in my Auris any car charger different than Tom Tom one  pops out easily. Shame really, because  the charger is good. You can try if you like it. Here some pictures. 

Thanks for the reply - will have a think. I’m in no rush as I still haven’t got the car yet! Just looking ahead at a few accessories during my wait! 👍

[TonyHSD]

2 hours ago, Newbie47 said:

Thanks for the reply - will have a think. I’m in no rush as I still haven’t got the car yet! Just looking ahead at a few accessories during my wait! 👍

I think it might be ok for your new car. I had another one similar small and powerful but again it was jumping out easily and gave it to my gf recent Hyundai and fits just fine. Here it is a link for it If anything interested 👌

https://www.amazon.co.uk/dp/B09BVDK36H?ref_=cm_sw_r_cp_ud_dp_ATS3TARS3HA3CB807D2H
 

And here is the only one that fits snugly into Auris 2010 and works great too, unfortunately only usb a, but I have an adapter for usb c applications. It’s also a fast charger too. 👌

https://www.amazon.co.uk/dp/B074JBT27P?ref_=cm_sw_r_cp_ud_dp_N32PFHHEE7XK6ZPXW7RZ

[Dala]

Socket With Voltmeter Scale Display : https://www.aliexpress.com/item/1005003628389527.html

driving during the day does not charge the Battery, it only maintains it
kill who invented "smart charging"
while driving every day I measured the following data:

The big problem is that 12.7V-13V is not a floating voltage
It would be enough to increase the float voltage to 13.5V-14V and the car Battery would last much longer
EU regulation on reducing CO2 = smart charging = faster death of car batteries

perhaps only in my case are these values bad
It will be nice if someone adds measured values - for comparison

[preperationlaunch]

I'm not sure smart charging is the problem when you put it into context.

The car has a very small Lithium HV Battery, the 12v Battery is about equivalent in size. It makes little sense to charge one Battery from another if you can avoid it, charging losses are high in lead acid batteries.

@Dala are your voltages measured when the engine isn't running and the car is in READY? As logically, it'd make sense to avoid charging the 12v battery when the HV battery isn't being charged.

That won't stop the lights/HVAC etc from being supplied by the DC-DC converter, the 12.7 volts could still be coming from it, with the 12v battery essentially idling.

[Dala]

Yesterday I drove 2x 100 km during the day without lights = over 4 hours
99% of the time ! the tester through the cigarette lighter showed 13 V
the pandora system displayed 12.8V
average is 12.9V in 4 hours of driving
if I turn on the lights while driving - just turn on the parking light - the system will start showing 14.4V

"I'm sure smart charging is the problem "
- - - - - - - - - - - - - - - - - - -

"The car has a very small Lithium HV Battery, the 12v Battery is about equivalent in size."

are you sure ? 
don't you mean dimensions? 
even the dimensions of the HV Battery is larger according to the videos on youtube

Battery pack voltage 177.6 V
Number of Li-ion battery cells in the pack 48
Li-ion battery cell voltage 3.7 V

- - - - - - - - - - - - - -  - - - - - - - 

"As logically, it would make sense to avoid charging a 12V battery when the HV battery is not charging."

Not true. The 12V car battery is charged in "READY MODE" even if the HV battery is not charged.
THAT'S WHY Toyota recommends 1 hour a week in "READY" mode when the car is parked.
When driving downhill, the HV battery was also recharged and tester through the cigarette lighter showed 13 V.

[preperationlaunch]

On 5/15/2022 at 2:08 PM, Dala said:

Yesterday I drove 2x 100 km during the day without lights = over 4 hours
99% of the time ! the tester through the cigarette lighter showed 13 V
the pandora system displayed 12.8V
average is 12.9V in 4 hours of driving
if I turn on the lights while driving - just turn on the parking light - the system will start showing 14.4V

"I'm sure smart charging is the problem "
- - - - - - - - - - - - - - - - - - -

"The car has a very small Lithium HV battery, the 12v battery is about equivalent in size."

are you sure ? 
don't you mean dimensions? 
even the dimensions of the HV battery is larger according to the videos on youtube

Battery pack voltage 177.6 V
Number of Li-ion battery cells in the pack 48
Li-ion battery cell voltage 3.7 V

- - - - - - - - - - - - - -  - - - - - - - 

"As logically, it would make sense to avoid charging a 12V battery when the HV battery is not charging."

Not true. The 12V car battery is charged in "READY MODE" even if the HV battery is not charged.
THAT'S WHY Toyota recommends 1 hour a week in "READY" mode when the car is parked.
When driving downhill, the HV battery was also recharged and tester through the cigarette lighter showed 13 V.

Lead acid Battery is 12v x 35Ah = 420Wh

Lithium HV Battery is quoted as 700Wh nominal.

They're in the same ballpark in raw capacity.

What is the problem with the 12v system not being supplied 14v at all times.

If the 12v Battery is fully charged anyway, then the car can save energy by not holding it at a float charge. Said energy would just be being dissipated as heat.

Any 12v loads will be being powered by the DC-DC converter, rather than the 12v battery.

[Dala]

May 14, 2022
car open at 09:05 - 12.5V
the ride starts at 09:15
total drive 200 km = more than 4 hours drive (2 hours there, 2 hours back, the rest of the parking time)
when driving on the road, the Battery charged 12.9V about 99% of the time
return at 18:20, car closed
at 18:45 measured - 12.5V
--------------------------------------------------
May 15, 2022
car open at 05:30 - 12.3V = 60% Battery capacity
this day without driving - solar panel connection
-------------------------------------------------- -
result:
after more than 4 hours of driving without lights a day, the Battery is charged so that the next morning it has a capacity of 60%
===============================
May 16 car open at 06:20 - 12.6V
disconnecting the solar panel
drive 60 minutes in the morning with lights - when driving 14.4V
evening return 45 minutes with lights - when driving 14.2V
return 21:00, car closed
at 21:20 measured 12.7V
-------------------------------------------------- ----------------------
May 17, 2022
car open at 05:45 - 12.5V = 90% of battery capacity
-------------------------------------------------- ----------------------
result:
after 1 hour and 45 minutes of driving with lights per day, the battery is charged so that the next morning it has a capacity of 90%
===================================
paradox:
20W solar panel charges the car battery from 60% to 90% in 1 day,
driving without lights charges the car battery from 90% to 60% in 1 day

[Gerg]

I have two cheap cigarette lighter voltmeters; bought at different times and from different sellers, but both through Aliexpress.  They have a simple digital display, so not like your one.

On one occasion, I was trying them 'back to back' as I was getting readings that were a little unexpected on several cars.

I had the use of an adjustable, table-top DC power supply, so attached them to that.  What I found was that their displayed reading on a slowly rising voltage differed by as much as 0.15v over that displayed on a slowly lowering voltage.  This was on both plug-in meters, and confirmed with a standalone conventional DVM at the same time. 

Whilst this a very small mis-measurement, and not on the same type of meter as yours, with the level of accuracy you are working with I thought this was worth mentioning as a possible small variable.

Similarly to you, on my daughter's Auris hybrid, after a having a variety of long drives in daylight, a CTEK MX5 charger was used on the 12v Battery, just as an experiment (that charger is quite new to me).  It took 4 hours to report that it had finished charging.  Pre-charging, the Battery sat at 12.2 volts. 

But, the Battery is 9 years old, so maybe that is not representative! Although that battery has never failed to start the car. 

[Dala]

testing the same measurement system
Based on this test, I decided to buy

https://youtu.be/FeN8ULJnIas

I have the same values for the CTEK charger
before charging 12.1V - 12.3V
charging time up to 100% 4-5 hours

I left the last charging "float mode" longer - 30 hours
pandora showed a stable voltage of 13.9 V (at an outdoor temperature of 10 ° C)
I have already inserted the conversion table here
The 12V car Battery has been in much better condition since then

I recommend not turning off CTEK after reaching 100%
it is better to leave it in "floating mode" for a while.

[Roy124]

Just a niggle on cigarette plug in voltmeter; you need to  switch to Ready mode first. 

If car goes to Ready mode, no problem, Battery serviceable.  If it doesn't, Battery flat. 

If you want to monitor the Battery when the car is not in use you either need a direct reading voltmeter or a bluetooth voltmeter. 

[Dala]

Or an application with remote reading of the car Battery voltage.
Such as the Pandora protection I use.
It obtains data directly from CANBUS.