Ctek Battery Conditioners for Hybrids

SH20 · April 5, 2020

I've used a Ctek Battery on all my cars over the years, simply the best conditioners out there. My 12v Battery on my ES300h is in the boot but have never coupled my charger to the Battery in 7 months.

Does anyone use a Ctek charger on their hybrid Lexus? I used it all the time on my LS460 just to ensure the Battery was always fully charged. Not sure whether a hybrid needs to have the 12v Battery on a Ctek conditioner/charger. Any thoughts?? You can now get a Ctek toggle device which is fitted to the Battery by a pair of wires but has a traffic light LED display showing the health of the Battery at a glance, green for fully charged, amber for get ready to charge and red for Battery needs charging. I'm asking these questions because of the restricted use of cars now which means my car sits in the garage for long periods.

Britprius · April 5, 2020

The Lexus hybrids possibly require the 12 volt Battery to be charged more than it's non hybrid counterparts. In general it seems that Lexus tend to put smaller or lower amp hour capacity batteries in the hybrids. It is a constant problem in the pages of LOC.
The Ctek charger is eminently suitable for charging your ES300H 12 volt Battery.

John.

Zotto · April 6, 2020

Give also a look about type of battery; usually they are AGM and require the proper setting on Ctek.

Ctek, but also many other chargers working with same control chip, can be used also by charge maintainer leaving it connected; it can be used also for reconditioning old batteries.

Farqui · April 6, 2020

I just watched a Harry's Garage video about storing vehicles and he shows a Ctek Battery indicator that you can leave permanently hooked up that uses a simple traffic light system to show the state of the Battery at a glance.

I didn't know about these but they seem like a neat way to have a quick hook up to the charger should your Battery indicate it needs a boost.

They aren't expensive either 😉

https://www.ctek.com/products/vehicle/indicator-eyelet-m8

Has anyone use one?

NemesisUK · April 6, 2020

I used one of those on my CLS55, only problem was just opening the boot to check the connector indicators would always drop the light from green to amber!

But very convenient for a quick connection, I left the leads permanently attached to the Battery (well my MB dealership connected it all up for me!) and simply tucked the connector into the trim when not used.

SH20 · April 6, 2020

Thanks Britprius for your reply.

Zotto, is AGM a Battery brand name or an electrical term abbreviation of some sort. Also what would be the proper setting be on a Ctek charger I wonder?

Lexus advised me today after I sent them an inquiry about using a trickle charger like Ctek. The official Lexus technical answer was that it was ok to use an external charger but if you leave the car in ready mode the hybrid Battery will top up the 12 volt Battery in the boot. It would need to be in ready mode for about an hour once or twice a week. However if the hybrid Battery is a bit low then the engine will automatically start to keep the hybrid Battery topped up in order for the hybrid Battery to top up the 12volt Battery. Don't really like the idea of the engine stopping and starting just to keep the 12 volt Battery topped up. I'll use the Ctek if Zotto can clarify the setting query.

Zotto · April 6, 2020

Ehm, I have not a Ctek charger, but a more cheaper charger sold by Lidl . Anyway: https://www.bargainsell.co.uk/charging-agm-battery-with-ctek.html

John Hutton · April 6, 2020

Hi Steve

hopefully I can answer this one. AGM stands for Absorbent Glass Mat you can google it to find out the differences if you are interested.

The CTEK MXS 5.0 has a charge mode specifically for AGM batteries - it just needs one more press of the 'mode' button than a standard wet cell type car Battery and is clearly identified on the charger so you should have no problems getting the right setting.

Hope that helps

John

Britprius · April 6, 2020

Although the chemistry in AGM ,and normal flooded lead acid batteries is basically the same the AGM has a slightly higher terminal voltage. The AGM voltage is 14.2 volts while the flooded Battery is 13.8 volts.
The old style transformer chargers will generally charge both types, but are not suitable for trickle charging "being permanently left connected" as they tend to overcharge the batteries.

Chargers designed for flooded batteries tend not to fully charge AGM batteries because the output voltage is to low. They will however charge AGM batteries to a point where they can be used to start a car, but because the Battery never reaches full charge there is a risk of some sulphasion.

AGM Battery chargers will charge both types of Battery fully, but can slightly over charge lead acid batteries so that the Battery may need topping up with distilled water.

Most modern Battery chargers are capable by switching or auto means of charging both type of Battery.

I do not now if this applies to the Ctek charger, but the Aldi/Lidl chargers are excellent chargers with a blue illuminated liquid crystal voltage display, charge type, and level. The only downside is that if the supply to the charger fails because of a power cut it does not restart automatically. The on off button has to be pressed to start charging. At circa £12 they are an excellent buy with a 3 year guarantee.

John.

SH20 · April 6, 2020

Thanks guys for all the info, you all have so much knowledge about these sort of things, very grateful. I have checked my Ctek charger and as John correctly says there is a AGM indicator light which comes on if you press the mode button several times. However the 12v Battery in my car has no markings to suggest it is an AGM unit because I'm assuming the words contains sulphuric acid means it is a lead acid Battery. Please let me know if my assumption is wrong. Thus ensuring that I will not be engaging the AGM mode on the Ctek.

I have just ordered the dongle traffic light indicator that Farqui (Lee) mentioned off eBay for just over £11 incl postage. It seems like a good idea to be able to just look at it and wait to see what colour LED flashes , red = needs charging, amber = will need a charge soon and green = fully charged. I saw the same Harry's Garage YouTube video on storing cars which included a piece about this smart device.

Thanks again for the help

NemesisUK · April 6, 2020

AGM batteries use sulphuric acid/water mix just as traditional wet or flooded batteries do. In fact I believe all batteries use sulphuric acid/water as the electrolyte

https://www.batterystuff.com/kb/articles/5-battery-types-explained-sealed-agm-gel.html

Zotto · April 7, 2020

Update: even if many hybrid cars use AGM 12V batteries, this is NOT true for all models, in my RX 450h the Battery is a standard Pb 12V one with 70 Ah capacity and has to be charged with standard settings; so, before using a charger give a look to your Battery type or, in doubt, keep charging mode to "normal" Battery to avoid overcharging.

Delphius1 · April 7, 2020

AGM and Gel type batteries tend to be sealed and need a different charging regime to "normal" wet lead acid batteries. Being a sealed Battery, you can only charge AGM and Gel batteries at a very low charge rate. This prevents the batteries producing excess gas. If they did produce excess gas, the case would blow, so they have valves that vent the gas over a certain pressure. If gas escapes out of the vents, that's your Battery capacity escaping into the atmosphere and you can't ever get it back.

Always use the correct charger with AGM and Gel batteries. Don't be tempted to use anything else as it can ruin the Battery.

One thing that people forget is that when an AGM or Gel Battery is flat, it can take days to fully recharge because of the low charge rate. Charging overnight isn't enough. Also if you jump start the car after the Battery has gone flat the charging circuit on the car is designed to charge at the specified low charge rate, so you'd have to drive the car round for days non-stop to fully charge the Battery. :-) Open wet lead acid batteries can quite happily sit gassing for days and you just top up the electrolyte with distilled water. You can't do that on a sealed Battery. Even sealed wet lead acid batteries should be charged to avoid gassing because you can't top the electrolyte back up.

Basically AGM and Gel batteries hold a small amount of acid electrolyte close to the lead plates in a sort of thin sandwich, which makes them smaller and lighter. AGM batteries hold the electrolyte in a wet mat held up to the lead plates (hence the name Absorbed Glass Mat) and Gel batteries hold the electrolyte in a sheet of gel essentially. They work more or less the same as a wet lead acid Battery (where the lead plate is suspended in a bath of electrolyte: So bulky!

You can get more technical as the charging regimes for each type of Battery is different, but the essential thing is to always use a charger designed for the type of Battery you have.

Hooking up an old 4 or 8 Amp Battery charger to an AGM or Gel Battery (or even sealed wet battery) is a sure-fire way to get them gassing thereby reducing the capacity and rendering them useless.

SH20 · April 7, 2020

Thanks Mark plenty to think about but from what you have said even more need to know what Battery I have in my car. I've asked Lexus what type of Battery my car has and waiting for them to send me the info. Is it or isn't it an AGM Battery. I want to charge it correctly using my Ctek charger which allows me to select AGM as a setting.

Just to be sure Mark can you clarify your comment "Even sealed wet lead acid batteries should be charged to avoid gassing because you can't top the electrolyte back up."

Should it be: avoid charging a sealed lead acid Battery to avoid gassing if you can't top up the electrolyte. Sorry I'm being a bit thick here.

My Battery looks like it has plugs that can be removed and one which is a little window currently showing the colour blue when you look down it. Not sure what blue would mean, I wonder if it should be green to indicate fully charged. As I said previously there is no label or letters that suggest it's AGM and the Battery itself is hardly a large Battery compared to batteries my LS460 or Jaguar XJ had. Tried attaching a couple of photos of the Battery but wouldn't load for some reason.

SH20 · April 7, 2020

Just heard back from Lexus Customer Relations. ES300h cars are fitted with AGM batteries. Now I can charge with my Ctek using the correct setting.

Delphius1 · April 8, 2020

22 hours ago, SH20 said:

Thanks Mark plenty to think about but from what you have said even more need to know what battery I have in my car. I've asked Lexus what type of battery my car has and waiting for them to send me the info. Is it or isn't it an AGM battery.    I want to charge it correctly using my Ctek charger which allows me to select AGM as a setting.

Just to be sure Mark can you clarify your comment "Even sealed wet lead acid batteries should be charged to avoid gassing because you can't top the electrolyte back up."

Should it be:    avoid charging a sealed lead acid battery to avoid gassing if you can't top up the electrolyte. Sorry I'm being a bit thick here.

My battery looks like it has plugs that can be removed and one which is a little window currently showing the colour blue when you look down it. Not sure what blue would mean, I wonder if it should be green to indicate fully charged.    As I said previously there is no label or letters that suggest it's AGM and the battery itself is hardly a large battery compared to batteries my LS460 or Jaguar XJ had.    Tried attaching a couple of photos of the battery but wouldn't load for some reason.

Steve,

It's the same thing. Basically you avoid using a charge current high enough to produce gas in the Battery.

ANY sealed lead acid Battery needs to be charged at a low charge rate to avoid excess gas production. We all know that lead acid batteries produce hydrogen and oxygen as they are charged. The trick with a sealed Battery is you charge it slowly enough so that either no gas or very little gas is produced. The hydrogen and oxygen will eventually recombine in the Battery case back to water and all is good, the Battery isn't damaged.

If you overcharge a sealed Battery, it starts to produce so much gas the pressure in the case builds up to dangerous levels and to avoid the case splitting from the pressure, the valves in the vents open and allow the gasses to exit the Battery case. But that means you've lost that hydrogen and oxygen and it can never recombine in the Battery case. You've just lost some electrolyte. If you continue to overcharge the Battery, eventually it looses so much electrolyte it starts to fail. A loss of capacity is the result, so you end up effectively with a dead Battery.

If your Battery has removable plugs that you can use to top up the electrolyte then it's not a sealed Battery. Sealed batteries don't have any ports. Sometimes sealed batteries are called maintenance free or sealed for life.

As for the charge state window, the colour depends on the manufacturer of the Battery. Not sure what blue means. Generally green is charged and good, red is low charge and no colour is low electrolyte. Red and green usually mean the same thing but manufacturers use different colours for the other Battery states.

Way back when I was a young apprentice working on emergency power supplies I had an explosive education into how much hydrogen and oxygen a big bank of rapidly charging wet lead acid batteries can produce and how much acid comes out of a case when you blow it apart. 😞

SH20 · April 8, 2020

That sounds really hairy Mark, exploding batteries. I'm just waiting for the ctek dongle with the conditioner traffic light feature so I can connect first to see what the device is telling me as to whether it's charged or depleted.

Question: was it practise back in the day to rapidly charge a bank of wet lead acid batteries or was there a special reason for the rapid charge?

RgrWynne · April 8, 2020

On 4/7/2020 at 11:55 AM, SH20 said:

Thanks Mark plenty to think about but from what you have said even more need to know what battery I have in my car. I've asked Lexus what type of battery my car has and waiting for them to send me the info. Is it or isn't it an AGM battery. I want to charge it correctly using my Ctek charger which allows me to select AGM as a setting.

Hi Steve, with a CTek M5 charger on the basic setting you will not harm anything on your car. The charger will not allow it, but it will also charge your Battery and it is designed if necessary to be left permanently on the Battery, on the vehicle. I leave mine on all the time, and after an extended holiday I used it on my wife’s Jazz, which is actually an AGM, but I wasn’t sure, so just used the basic setting. All totally fine. Obviously if you now know it is an AGM, it makes sense to use that setting on the charger. Good luck, cheers, Roger

Britprius · April 29, 2020

On 4/8/2020 at 4:28 PM, SH20 said:

That sounds really hairy Mark, exploding batteries. I'm just waiting for the ctek dongle with the conditioner traffic light feature so I can connect first to see what the device is telling me as to whether it's charged or depleted.

Question: was it practise back in the day to rapidly charge a bank of wet lead acid batteries or was there a special reason for the rapid charge?

Apart from cars another use of large lead acid batteries is in industrial forklift trucks, golf buggies, the old style milk floats, and powered hand operated trolleys. These tend to be charged at high rates because they have high AH capacity batteries often in to the thousands of AH against the 40 to 70 AH typically used in cars.They are charged at 80 amps or more usually over night so that they can be used during the day. These batteries need constant electrolyte level checking, and topping up with distilled water. When on charge they should be in an area that there is no source of combustion, and well ventilated. Large amounts of hydrogen, and oxygen are given off and explosions are a real risk.
These batteries area designed so that individual cells can be removed, and changed when they become sulphated.

John.

Barry14UK · April 29, 2020

One recommendation that has been made when using CETEK and possibly other smart chargers is to avoid using the RECON mode when charging AGM batteries.