CTEK Chargers

[lmoengnr]

While charging a 12v lead acid batteries is generally safe, CTEK do state the following in the owners manual safety section:

Always check that the charger has switched to STEP 7 before leaving the charger unattended​

and connected for long periods. If the charger has not switched to STEP 7 within​

50 hours, this is an indication of an error. Manually disconnect the charger.​

CTEK also states that the time taken to charge an empty battery to 80% charge as follows:

​

BATTERY SIZE (Ah)​	TIME TO 80% CHARGED​
2Ah​	2h​
8Ah​	8h​
20Ah​	4h​
60Ah​	12h​
110Ah​	26h​

Note I've diligently copied what seems to be errors from CTEK's manual... As shown above, an empty 110Ah battery can take 26 hours to bulk charge to 80%. Oddly the following page provides the charging programs and options combinations which shows the bulk charge (stage 3) is a maximum of 20 hours. Gotta love the clarity and error free owners manual that CTEK provide

As is, i think our commodore V8 batteries are 80Ah and as such shouldn't require more than 20 odd hours of bulk charge before they get to the float program as provided by the green LED stage 7. So just a short time of attended supervision needed

Sadly it takes a long 10 days before the charger goes to pulse program provided by stage 8 (which is annoyingly long)..

So in CTEKS mind, you must supervise the charging process by keeping an eye on the charge process until the stage 7 green LED has turned on, which can take up to 50 hrs... Year right...

Reality should be, if one is worried about setting fire to their house, then they should keep an eye on the battery temperature and that of the charger itself for up to 2 days and 2 nights to ensure they don't get too hot and bad things happen. How real is the probability of it burning down your house who really knows... But it's hardly a set and forget charger which is how it is marketed. The owners manual also contains inconsistencies and the whole thing seems a bit of a bait and switch with their safety warning stating supervision is required during bulk charge

As for pulse program (stage 8), it's unclear how low the battery voltage is allowed to go before the charger kicks in to top up the battery as CTEK doesn't mention such within their manual. In CTEK's video, it states the voltage can drop 5% before it's pulse charged

Frustratingly, a fully charged battery is nominally at 2.1V/cell = 12.6 volts and a 5% drop will see the voltage drop to 11.97V before the pulse charge kicks in. Such a low voltage is well within sulfation territory, so whats the go? What open circuit voltage are people seeing when in stage 8 pulse mode and when does the pulse charge actually kick in to pump up to the battery to 2.25V/cell or 13.6V which is 100% float charge level if that's what it actually does?

The lack of real detail in the manual is annoying as I've had other older brand float charger kill my batteries in the past. I simply want to make sure all is ok the CTEK charger and it works as it is meant to and my MSE battery wont sulfate and the charger wont set fire to my house (ok not reallty worried about a house fire as quality branded electronics are rather good thee days)...

I think if a Commodore battery needs longer than 20 hours to charge, it's time for a new battery.
I have 2 CTEK chargers, a MXS 5.0 for charging and a MXS 0.8 for maintaining the Maloo's battery.

 

[gtrboyy]

I rate c-tek highly & not shy about recommending them to family/friends but still don't trust leaving equipment on or unattended...doesn't matter if it's trickle charger...an air compressor or soldering iron.

You could be that one in a thousand....just common sense not worth arguing over.

 

[Skylarking]

I think if a Commodore battery needs longer than 20 hours to charge, it's time for a new battery.
I have 2 CTEK chargers, a MXS 5.0 for charging and a MXS 0.8 for maintaining the Maloo's battery.

Yes, I'd think after 20 hrs an 80Ah battery is stufed as well, even though CTEK state a 110Ah battery is catcus after 50hrs of bulk charge without progression to stage 7

My MSE battery is fine. It's just that I don't know the parameters around the pusle charge mode and I simply want some clarity on it

 

[gtrboyy]

I've recharged batteries even the auto sparky said was beyond dead with my c-tek when first bought it just for the experiment....worst one took about a week but was only turning charger on while I was home for 8hrs or so each day & kept checking up on it in case of kaboomski

 

[shane_3800]

While charging a 12v lead acid batteries is generally safe, CTEK do state the following in the owners manual safety section:

Always check that the charger has switched to STEP 7 before leaving the charger unattended​

and connected for long periods. If the charger has not switched to STEP 7 within​

50 hours, this is an indication of an error. Manually disconnect the charger.​

CTEK also states that the time taken to charge an empty battery to 80% charge as follows:

​

BATTERY SIZE (Ah)​	TIME TO 80% CHARGED​
2Ah​	2h​
8Ah​	8h​
20Ah​	4h​
60Ah​	12h​
110Ah​	26h​

Note I've diligently copied what seems to be errors from CTEK's manual... As shown above, an empty 110Ah battery can take 26 hours to bulk charge to 80%. Oddly the following page provides the charging programs and options combinations which shows the bulk charge (stage 3) is a maximum of 20 hours. Gotta love the clarity and error free owners manual that CTEK provide

As is, i think our commodore V8 batteries are 80Ah and as such shouldn't require more than 20 odd hours of bulk charge before they get to the float program as provided by the green LED stage 7. So just a short time of attended supervision needed

Sadly it takes a long 10 days before the charger goes to pulse program provided by stage 8 (which is annoyingly long)..

So in CTEKS mind, you must supervise the charging process by keeping an eye on the charge process until the stage 7 green LED has turned on, which can take up to 50 hrs... Year right...

Reality should be, if one is worried about setting fire to their house, then they should keep an eye on the battery temperature and that of the charger itself for up to 2 days and 2 nights to ensure they don't get too hot and bad things happen. How real is the probability of it burning down your house who really knows... But it's hardly a set and forget charger which is how it is marketed. The owners manual also contains inconsistencies and the whole thing seems a bit of a bait and switch with their safety warning stating supervision is required during bulk charge

As for pulse program (stage 8), it's unclear how low the battery voltage is allowed to go before the charger kicks in to top up the battery as CTEK doesn't mention such within their manual. In CTEK's video, it states the voltage can drop 5% before it's pulse charged

Frustratingly, a fully charged battery is nominally at 2.1V/cell = 12.6 volts and a 5% drop will see the voltage drop to 11.97V before the pulse charge kicks in. Such a low voltage is well within sulfation territory, so whats the go? What open circuit voltage are people seeing when in stage 8 pulse mode and when does the pulse charge actually kick in to pump up to the battery to 2.25V/cell or 13.6V which is 100% float charge level if that's what it actually does?

The lack of real detail in the manual is annoying as I've had other older brand float charger kill my batteries in the past. I simply want to make sure all is ok the CTEK charger and it works as it is meant to and my MSE battery wont sulfate and the charger wont set fire to my house (ok not reallty worried about a house fire as quality branded electronics are rather good thee days)...

I've had my 10amp go to stage 8 overnight. Yes it usually sits at 7 but it might go to 8 early if the temp probe is in?????

 

[shane_3800]

Stage 7 is float charge mode while stage 8 is pulse charge mode.

In float mode you should see the battery open circuit voltage held at 13.6V but while in pulse mode it slowly drops due to self discharge. It's not clear when the pulse charge kicks in to boost the battery voltage, nor is it clean what voltage it boosts it back up to? Any thoughts?

The pulse must be like a 11v down and 15v up.

 

[shane_3800]

I've recharged batteries even the auto sparky said was beyond dead with my c-tek when first bought it just for the experiment....worst one took about a week but was only turning charger on while I was home for 8hrs or so each day & kept checking up on it in case of kaboomski

Yea if you use reco mode it will 16v pulse charge in stage 6 and it knocks the sulfate off the plates.
I did this to a battery also using the rescue additive and it lasted 6 months extra but when I opened the caps the plates were porus as with big holes lol.

 

[tommy_z]

I think a lot of reports of faults and errors or fires with any electronic item need to be looked at in context. It’s like saying a toy that contains a battery exploded and caught fire then you think about where has the parent bought the toy from… Alibaba with no name and shipped overseas from an Asian country and no labels, go figure. I sound like a snob but I would only purchase brand name kitchen appliances as I don’t want ones I buy on eBay for a lower price to cause electrical problems like short circuits.

If there was something systemic with the Ctek then we will have known by now considering how many are out there and how many years they’ve been making these.

Any electronic item will carry a risk of going in flames but all I can say is risk minimisation.

I have two Ctek MXS5.0s. With lockdowns and lack of time, one of my cars has not been run and nor has it been disconnected from the charger for the past 5 months. It always moves between 7 and 8 on the charger.

A few things I’ve got with mine:
1. I only connect the charger to the ports in the engine bay, not direct to the battery.
2. The charger sits separately by hanging off the ceiling to the side of the car.
3. The charger is away from rain and the elements. There is no direct sunlight on it.
4. For many hours of the day, there is someone at home.
5. There’s a hose closeby if I do need to douse a fire as it’s the garage.

A few things come to mind… electronics don’t mix with water so don’t keep it close to water or moisture which could affect the way it operates. And also we all know how the Ctek gets hot when charging so keep it out of the sun and away from an enclosed space like the boot or under the bonnet. A 2m extension cable is only $20 and that lets me hang the charger away from the car (and prevents me from forgetting to disconnect when I do find time once in a blue moon to drive!!).

You’ll never make your chance of getting a fire 0 but all I know is I’ve done whatever I can to be sensible to minimise that risk as close to 0 as I can.

I trust the two chargers I have and they haven’t skipped a beat over the past 3 years they’ve worked so I’d like to think I ain’t going to have a problem! I’ve paid the money for them to do the job they were advertised to do, which is set and forget 24/7, and they’re doing it fine.

 

[jpetrou]

I have 2 Ctek MXS-5 chargers hooked up to my VK (running Ecotec conversion) and Monaro CV8 for months at any given time.

I have used the special connector supplied, black wire to earth and red wire to positive terminal on battery.

No issues apart from having to add distilled water to bring up battery electrolyte level, as some of the electrolyte drops (usually once or twice a year).

 

[stooge]

If there was something systemic with the Ctek then we will have known by now considering how many are out there and how many years they’ve been making these.

it depends what is catching on fire...

if the battery is catching on fire then there is not a lot the charger can do if the battery is faulty.
if the charger is catching on fire then yes it could be a faulty design because the charger should have thermal protection that will kill its power to prevent overheating and catching on fire.
the charger should also be designed to dissipate the heat it will create properly using passive or active cooling, designing something to look nice is not always the best way.

even with poor ventilation the charger should thermally protect itself well before the point of meltdown

it is hard to tell what is the cause from peoples vague reports and they will always blame the charger but given that there are millions of them in use with few reports i would think that it is just an unlucky few.

using it properly is the best way, the extension cord is a good idea removing the charger from being on or in the vehicle.
i only connect the charger directly to the battery terminals(both + and -) because you want the charger reading the battery condition as close to the source as possible.

if someone was really worried they could build a simple thermal protection system with a few parts from jaycar like a thermal switch attached to the body of the charger and some other bits to kill the 240v source to the charger or the 12v feed to the battery if the body of the charger gets to a certain temp.

i use a NO thermal switch on the active cooling unit i made for my house solar inverter, before making it my inverter was peaking at around 100deg on a warm day with its passive cooling so i used a 50deg thermal switch on the inverters heatsink that switches on 3 90mm fans which force air through the inverters heatsink.
doing this has the inverter sit around 60deg, when the sun goes down the temp drops and the fans switch off because the inverter is not producing power so it does not produce heat and the thermal switch returns to its NO state.