Flat battery

[westo3]

Left my car for four weeks and when I came to start it the Battery was flat. Charged it up using a Ctek and it has been fine until today when I opened the door and the siren went off and an error reading of blind spot monitoring not working. I have since jumped started it and got it going. It had not been driven for a week which is not all that long. Not too sure why the Battery should go again on a three year old car. I only have an iPod in the car and I am sure that turns off with the car. It may be that my Battery was damaged having completely drained the first time? I am going to do a recon with the Ctek but I am not sure if it is an AMG or not the numbers on the Panasonic are 20HR 57Ah CCA 450A D26 (JIS). Can anyone help? GS300h premier 2017.

[Vlady]

Hi Nick, have a look here! 

 

I think your Battery should be an AGM and I think I have the same Battery! Hope it helps! Good luck! And keep us posted how it goes!

[westo3]

Cheers Vlad I will go ahead and recon it on the AGM setting. Still puzzles me why it should be flat after only a week. Will see what happens after the recharge.

[RgrWynne]

Actually won’t make much difference which setting you use . Just leave it on until all the lights are showing, I leave mine on all the time.

[westo3]

Thanks Roger. Still not too sure why the Battery should go down within a week

[toe]

I wouldn't use the recond function on the CTek for the AGM. AGM doesn't really like high voltage pulses and also I am not sure if this is bad for the cars electronics if you leave the terminal connected. The "normal" mode is what I use for AGM, if you read the manual, the AGM mode is only for certain AGM batteries, not the Panasonic one.

Also, what is the voltage of the Battery after you have charged it and left it overnight? The voltage will tell you the state of charge and you'll know if your batter is still good (can hold charge), or needs replacement.

 

[westo3]

Thanks Tony I did not realise that Panasonic AGM batteries did not like recon. I assume it is ok the leave the CTeck on normal charge over a period of time or are you saying it should be disconnected as soon as it is charged? What kind of reading should I be getting to show the Battery is holding its charge?

[ColinBarber]

4 minutes ago, westo3 said:

What kind of reading should I be getting to show the battery is holding its charge?

A fully charged AGM should have a terminal voltage of around 12.7 to 12.8 v. Left overnight you shouldn't really see it drop, 0.1 v lower at most.

[johnatg]

Batteries generally should be subject to Recond only very infrequently - it involves overchaging to promote gassing, which is supposed to stir up the electrolyte. I can't actually see that working very well with an AGM Battery. Setting to AGM doesn't make any difference to the recond function - the Battery gets hit with 15.8 v whether or not it's set to AGM. Probably not a great idea.

You can leave a smart charger connected indefinitely - chargers like Ctek ones will cycle the Battery near full charge and keep it in good condition (stage 8 - Pulse).

Stage 5 (Analyse) of the Ctek cycle is supposed to check the Battery for holding its charge. A red light should come on if there's a problem - I dunno - I've never tried to recharge a really faulty Battery with the Ctek.

[Barry14UK]

16 hours ago, toe said:

I wouldn't use the recond function on the CTek for the AGM. AGM doesn't really like high voltage pulses and also I am not sure if this is bad for the cars electronics if you leave the terminal connected. The "normal" mode is what I use for AGM, if you read the manual, the AGM mode is only for certain AGM batteries, not the Panasonic one.

 

 

The CTEK MXS 5. charger manual is not very explicit in certain respects to the point of being seemingly contradictory in some ways.   CTEK support says not to use the Recond on AGM batteries.  Also, eyelet connectors are provided for connection direct to the Battery and can be left on the car but the manual says that for batteries mounted inside the car the ground should be connected to the vehicle chassis remote from the fuel pipe and the Battery.  This aspect was put to CETEK support as here :-

why can the black not be connected to the - on the Battery?

 

CTEK Battery Chargers

4 months ago

Hi Mary Ellis. The Battery will be perfect charged if you connect to the Battery! The issues is - if your car is quite new and equipped with a Battery Management System (BMS)- that you need to connect to chassis to make the BMS notice that the Battery has been charged. The BMS is dialoguing with the vehicle computers to make the vehicle work as good as possible. And if the vehicle believes that the Battery is empty, the alternator will run more and create more CO2 than needed, other functions might not be working as good as planned. I hope this explains. Best regards CTEK Support

 

I am still not clear how this relates to our Lexus cars.  Anyone know if we have this BMS and if so what year/models?

I don't quite follow this because if the Battery was still connected to the car, it would be grounded anyway and why would you remove the Battery from it's terminal post? Would it be safer to connect the ground eye lead from the CTEK to a screw on the chassis anyway?

 

NB.  The Lexus manual also says to take the Neg lead from a charger to chassis when charging so if this is the case using the 2 eye connectors + and - connected to Battery is incorrect as the Neg should be taken direct to chassis. Could this be because it has BMS? 

 

[Herbie]

5 minutes ago, Barry14UK said:

I don't quite follow this because if the battery was still connected to the car, it would be grounded anyway

That says it all.

The negative terminal of the Battery has a great big cable connecting it to the body/chassis/engine. This connection forms a continuous metallic conductive path around the car so that any piece of metal, any bolt, any screw, anywhere in or on the car that is not specifically insulated from it, basically becomes the negative Battery terminal.

It simply does not matter whether the eyelet is connected directly to the negative Battery terminal or to some nearby screw.

It may possibly be some safety procedure (thinking of some stray spark igniting the hydrogen gas coming from the charging Battery somehow) but electrically speaking, it just does not matter - although I'm happy to be corrected if anyone can prove otherwise and will gladly hold my hand up.

[ColinBarber]

2 hours ago, Herbie said:

It may possibly be some safety procedure (thinking of some stray spark igniting the hydrogen gas coming from the charging battery somehow) but electrically speaking, it just does not matter - although I'm happy to be corrected if anyone can prove otherwise and will gladly hold my hand up.

This is the reason. The final connection should be made to a ground point away from the Battery so any spark produced won't ignite hydrogen gas produced by the Battery.

[westo3]

Having used the AGM recon setting on the Ctek I can assume I could have damaged the Battery? Have now taken the charger off and it is reading 12.7v I will test it in a couple of days time.  

[Barry14UK]

Nick,

I did the same thing, saw there was a mode on the CTEK for CAR with AGM and Recond and programmed accordingly.  This was some 4 days ago before I saw Tony and John's comment.  My Battery went up to 12.76v Car starts but I have not used it since. I have tried to minimize any drop by switching off courtesy lights and closing hatch manually, rather than using the button but of course it pulls in finally electrically.  I checked the Battery today and it showed 12.25v. I am wondering whether like you by using the AGM Recond mode I may have stuffed the Battery, although it was not holding up well previously so may not have been caused by this.  I will check again in a day or two.  I think there should be a prominent warning not to use the AGM Recond facility even though it is an option provided on the CTEK. See what CTEK Support say here 

Φ. Δ. 2 months ago (edited)

Hi. I own the CTEK MXS 5.0. Can i use the "recon." function wen the Battery is connected on the car?

 

CTEK Battery Chargers

2 months ago

Hi, Yes! All CTEK chargers are made to be electronic safe all the time and can be used in all modes whilst still connected to the vehicle. Please note that AGMs and GELs should not be RECONDed, all other types of lead acid batteries can be RECONDed once or twice a year. Best regards CTEK Support

I follow what Herbs and Colin have said about the possible reason for separately  grounding the neg of the charger during charging but this was not the reason CTEK gave as I pasted into my previous post.

If the voltage on my Battery continues to drop significantly, I will try normal charging this time and if this happens again will secure a large heavy normal LA Battery I have spare in the boot and connect by jump leads to existing Pan Battery so as not to lose settings if I have to use the car in an emergency before obtaining a suitable replacement.

[Herbie]

59 minutes ago, Barry14UK said:

I follow what Herbs and Colin have said about the possible reason for separately  grounding the neg of the charger during charging but this was not the reason CTEK gave as I pasted into my previous post.

So what's the point you're making Barry because I'm not sure?

The quote from CTEK's website doesn't seem make sense - maybe something was lost in translation or they didn't quite understand the question:

6 hours ago, Barry14UK said:

From the CTEK website - Question - why can the black not be connected to the - on the battery?:
Answer: The issues is - if your car is quite new and equipped with a Battery Management System (BMS)- that you need to connect to chassis to make the BMS notice that the battery has been charged.

First of all, we already know that the negative terminal of the Battery is connected to the chassis so how can any Battery management system know whether the CTEK is connected to the actual Battery post or to a random screw six inches away?

Answer: It can't - or at least, not so as to make any difference.

Every electrical conductor has resistance, so having the CTEK directly connected to the Battery post will obviously have the least resistance - let's say 0 Ohms. Connect it to a screw six inches away and that resistance between the lead and the Battery post may increase, say to 0.001 Ohms. Connect it to a screw six feet away and the resistance between the lead and Battery post will increase again, say to 0.1 Ohms.

In other words, the accuracy and operation of any BMS will be affected by where you choose to locate that negative lead, which would make it a very poorly designed system, which is why I think this is a red herring and why I still believe that BMS or not, there is still no viable electrical reason to avoid connecting directly to the negative Battery post.

6 hours ago, Barry14UK said:

From the CTEK website: And if the vehicle believes that the battery is empty, the alternator will run more and create more CO2 than needed, other functions might not be working as good as planned

The question had nothing to do with the alternator running, only whether the negative lead could be connected to the negative Battery post instead of the chassis, so again I think there's some confusion on CTEK's part

[westo3]

Have just checked my Battery and it is now 12.6 ie dropped one volt over 20 hours from full charge with the car locked and therefore alarm armed. Can I take it my Battery is ok?

[ColinBarber]

12 minutes ago, westo3 said:

Have just checked my battery and it is now 12.6 ie dropped one volt over 20 hours from full charge with the car locked and therefore alarm armed. Can I take it my battery is ok?

Yes. It's certainly not at the point where you need to consider changing it.

[westo3]

Thanks Colin, quite relived I have not sabotaged my own car!

[Herbie]

1 hour ago, westo3 said:

Have just checked my battery and it is now 12.6 ie dropped one volt over 20 hours from full charge with the car locked and therefore alarm armed. Can I take it my battery is ok?

This may help you for future reference:

[BoutTime]

14 hours ago, westo3 said:

Having used the AGM recon setting on the Ctek I can assume I could have damaged the battery? Have now taken the charger off and it is reading 12.7v I will test it in a couple of days time.  

If this could damage the Battery ctek wouldn’t make it an option. I have the comfort lead connected to the Battery. I haven’t used recon on on my CT but I used it on my Jaguar XF to recondition a fully depleted Battery. I also connected direct to the Battery. No problems. The previous owner had also replaced the Battery with a higher capacity unit and did not calibrate it to the car which Jaguar state you must do as it had a Battery monitoring system fitted. So all Jaguar requirements were effectively ignored but I never had a problem with the Battery.

 

ctek allow the user to select AGM recon mode which tells me all I need to know.

[BoutTime]

12 hours ago, Barry14UK said:

Nick,

I did the same thing, saw there was a mode on the CTEK for CAR with AGM and Recond and programmed accordingly.  This was some 4 days ago before I saw Tony and John's comment.  My battery went up to 12.76v Car starts but I have not used it since. I have tried to minimize any drop by switching off courtesy lights and closing hatch manually, rather than using the button but of course it pulls in finally electrically.  I checked the battery today and it showed 12.25v. I am wondering whether like you by using the AGM Recond mode I may have stuffed the battery, although it was not holding up well previously so may not have been caused by this.  I will check again in a day or two.  I think there should be a prominent warning not to use the AGM Recond facility even though it is an option provided on the CTEK. See what CTEK Support say here 

Φ. Δ. 2 months ago (edited)

Hi. I own the CTEK MXS 5.0. Can i use the "recon." function wen the battery is connected on the car?

 

 

CTEK Battery Chargers

2 months ago

Hi, Yes! All CTEK chargers are made to be electronic safe all the time and can be used in all modes whilst still connected to the vehicle. Please note that AGMs and GELs should not be RECONDed, all other types of lead acid batteries can be RECONDed once or twice a year. Best regards CTEK Support

I follow what Herbs and Colin have said about the possible reason for separately  grounding the neg of the charger during charging but this was not the reason CTEK gave as I pasted into my previous post.

If the voltage on my battery continues to drop significantly, I will try normal charging this time and if this happens again will secure a large heavy normal LA battery I have spare in the boot and connect by jump leads to existing Pan battery so as not to lose settings if I have to use the car in an emergency before obtaining a suitable replacement.

It just doesn’t make any sense. These chargers are incredibly smart. Why would ctek allow you to select AGM recond if AGM batteries should not be reconditioned?

[BoutTime]

From Jaguarforum.com where a poster asked ctek directly........

https://www.jaguarforum.com/showthread.php?t=107314

“A couple of replies from CTek in regards to AGM RECON setting and AGM charging selection.


Wow! That was a quick reply. 

Dear Sir

No.
Recond program is developed only for flooded batteries (including EFB), to remix the flooded acid inside.
The remixing/balancing is necessary to treat an already stratified Battery, or to prevent severe stratification.
AGM or GEL batteries are not flooded, and therefore does not suffer from stratification. That means Recond will not help AGM or GEL. 
Reconding an AGM Battery does not harm the Battery, but does not help either, so we cannot recommend recond program on AGM batteries either.
For GEL batteries, recond can be harmful, because using too high voltage can dry the gel inside the Battery and weaken the Battery instead of empowering it.
NOTE: 
When you choose Recond program, you should note that Recond program always starts with a normal Battery charging program. Then, after Battery has reached fully charged, Recond treatment itself is implemented. Depending of charger model and Battery size, Recond step lasts from ½ to 4 hours, on top of the charging time. 
When charger turns to green light, the program is completed. 

Yours, sincerely
Teresa
CTEK”

 

and...........

 

“I also asked why they had AMG listed in Normal Charge Mode and also in Snowflake/AGM the reply:-


Dear Sir;

There are many different Battery manufacturers and Battery models on the market. 
Recommendations regarding charging voltage vary a bit. 

Most AGM- batteries are recommended to charge with normal 14.4V voltage. 
Some AGM- batteries (and Ca-Ca batteries) require 14.7V (snowflake) for best treatment. 

Please check with the Battery manufacturer to get the correct information for your particular Battery. 

If no information is possible to acquire, use normal charging option, 14.4V It suits most lead/acid batteries, including GEL, EFB, AGM, etc. 
It is better to charge with a bit too low voltage than too high. 

Yours, sincerely, 
Teresa 
CTEK”

 

Edited April 14, 2020 by BoutTime

[Vlady]

Haven't driven my GS for more than a week and reading all the comments above I decided to charge the Battery, as a precaution only. 2 weeks ago I charged it as a Normal Battery with RECOND option On, only later I found out that my Battery is AGM! So this time I selected AGM mode (not RECOND) and put it on, it has been 4 hours since then and only 4th LED is lit.

Will wait! 🙂

My motorcycle Battery was connected to CTEK for 3 or 4 days constantly, just to keep Battery charged as I am not using the bike now (it is being repaired).

[BoutTime]

So to summarise recond won’t benefit an AGM Battery but won’t harm it either.

 

The question is would my AGM Battery in my CT benefit from the increased voltage of AGM mode?

[RgrWynne]

My CTek has been connected, as normal keeping Battery in good order. Car hasn’t moved now for over a week, but will be fine when I can go out. It can be left on permanently in normal mode and will charge any Battery up to its full charge, and then ‘smartly’ keep it there for when you need to use it.