Can we adjust the CTEK?

[FlyingTexan]

Mine is always trickle charging the house battery. Right now I’m at 75% and it’s only doing 3A. I leave a fridge in the back and I’d like to be able to charge it up quickly when I start. It seems to charge the main battery but then gets lazy on the house. Is there a way to tell it to do its job because I need the battery capacity. Making the battery last longer doesn’t help me any if it can’t the job I need it to do now.

 

[Tom109]

I am suspect of the smart alternator. It seem to under-perform unless you are in highly discharged state. I have a similar setup/needs to you, but put 200W solar on the roof.

 

[Rok_Dr]

Mine is always trickle charging the house battery. Right now I’m at 75% and it’s only doing 3A. I leave a fridge in the back and I’d like to be able to charge it up quickly when I start. It seems to charge the main battery but then gets lazy on the house. Is there a way to tell it to do its job because I need the battery capacity. Making the battery last longer doesn’t help me any if it can’t the job I need it to do now.

Some questions and comments to try and understand your problem better.

1. How are you monitoring the auxiliary battery charge? If you are using the centre display, it only monitors the charging of themain battery. There is no monitoring the of the auxiliary battery charging..
2. Are you powering the fridge from the 12 V socket in the cargo Bay area or directly from the accessory battery? The cargo Bay socket draws power directly from the main battery.
3. Ineos designed the auxiliary battery system purely to start the car when the main battery is flat. All loads are drawn from the main starter battery. As such the auxiliary battery is not a true “ House” battery.

Cheers
Steve

 

[Stealthn]

Subscribed - I bought the Iceco 250W battery for this purpose, it can run the fridge in Eco for over 24 hours and charges via the 110v socket in the rear when driving. I get about 14W charge in 30 minutes of driving.

 

[FlyingTexan]

Some questions and comments to try and understand your problem better.

1. How are you monitoring the auxiliary battery charge? If you are using the centre display, it only monitors the charging of themain battery. There is no monitoring the of the auxiliary battery charging..
2. Are you powering the fridge from the 12 V socket in the cargo Bay area or directly from the accessory battery? The cargo Bay socket draws power directly from the main battery.
3. Ineos designed the auxiliary battery system purely to start the car when the main battery is flat. All loads are drawn from the main starter battery. As such the auxiliary battery is not a true “ House” battery.

Cheers
Steve

Well, regardless, I’ve been running for 3hrs today and I’m at 81% with the alternator doing 2amps. It’s not wanting to charge past that for anything. I want it charging until the battery is full. I’m running my fridge off the 12v power outlet so it can make it through the night but if I get there and it quits charging at 75-80% I’m still not getting what I need.

 

[joejet]

I have left my car in the past for about 8 months unused I had 2x ctek charges (1 for each battery) and it maintained about 85% so I’m not sure it’s reporting correctly. The hightest I have ever seen the battery was 95% just after a service where it was for 4 days and plugged into there big charger (it was over a weekend). If I measure the battery voltage even with down to 55% state of charge it’s over 12.4 v, anyway even with 55% it starts easily and the Ctek can push it to 85 at least.

 

[Rok_Dr]

Well, regardless, I’ve been running for 3hrs today and I’m at 81% with the alternator doing 2amps. It’s not wanting to charge past that for anything. I want it charging until the battery is full. I’m running my fridge off the 12v power outlet so it can make it through the night but if I get there and it quits charging at 75-80% I’m still not getting what I need.

That’s normal charging behaviour for the Ineos battery management system unfortunately. In everyday use the system keeps the battery charged to around 80-85%.To monitor the charge of the auxiliary battery you’ll need to fit a shunt or cheap voltage monitor.

Section 11 in the Rok_Dr guide gives a detailed explanation of how the Ineos battery system works.

Cheers
Steve

 

[FlyingTexan]

I know it’s normal hence my post. I’m looking to change that.

 

[Clark Kent]

On a modern BMW there are two things relevant to this:

1. The dealer (perhaps also the owner) can change the target battery SOC via the iDrive interface. This is intended for vehicles that do a lot of city cycle driving when the alternator may not operate for long enough at high charging rates (typically during deceleration and overrun) to maintain the target ~80% SOC. More so if engine auto stop-start is enabled. SOC adjustment is not present in the Ineos head unit but it might still exist in the ECU (BMW: DME/DDE). A tuner might be able to access it and set a higher target SOC.

2. A BMW BMS needs to be updated after battery replacement. This is for late BMWs that run an AGM stop-start battery. As the installed battery ages the Ah capacity reduces and the internal resistance increases. The ECU automatically degrades the charging profile to account for this. When a new battery is installed the BMS needs to be updated with the battery age (installation date) and the new battery rated Ah so it resets the charging profile.
We have an EFB which I understand is closer to wet cell lead acid battery chemistry than AGM. An EFB might age differently to an AGM. I have no idea on that but it could introduce a mismatch in the default charging profile if there were no changes made for EFB versus AGM.
-----

I've not seen anyone comment on a BMS reset being performed after getting a new battery installed in their Grenadier. I don't know if this is accessible in the Ineos software. If this is not happening it might explain why the reported SOC becomes inaccurate over time and the observed charge rate seems low.
An undercharge condition could exist if the charging profile is designed for an AGM battery versus EFB. That assumes they do age differently and Ineos hasn't already allowed for it.

If Ineos techs can see the BMS then a battery load test and a BMS reset during annual servicing might be of benefit. Ask your dealer if the BMS is visible and configurable.

 

[Rok_Dr]

Thanks for the clarification @FlyingTexan and @Clark Kent for the system insights

I'm not aware of anyone to date that has been able to reprogram the BMS charging parameters. Agreed it's a question for Ineos and our dealers.

Cheers
Steve

 

[FlyingTexan]

So can I pull and replace this module to get rid of it? I’d rather my battery only last a couple years but give me access to the house battery and give me full charge. When I try to run my refrigerator it shuts off at the higher limit of the battery (75%) which I can adjust but I never wanted to risk it running down too much. The extra 20% is A LOT of usable battery. Plus the recharge rate is ruining it. Seems like a real waste to have the house battery only feed the starter. I guess one could bypass it all and run them in parallel but a bit defeating on the purpose. I’d like to be able to run one down using my fridge and Starlink and lights but leave the starter battery alone.

 

[FlyingTexan]

I did just drill in and mount a 5amp Norco smart charger.

 

[The_Ick]

Given that IG eliminated the ctek after 2024 most people are opting to install a redarc or victron bc/dc charger along with a lithium battery. I know the redarc is completely customizable. I believe the victron is as well.

 

[Clark Kent]

So can I pull and replace this module to get rid of it? I’d rather my battery only last a couple years but give me access to the house battery and give me full charge. When I try to run my refrigerator it shuts off at the higher limit of the battery (75%) which I can adjust but I never wanted to risk it running down too much. The extra 20% is A LOT of usable battery. Plus the recharge rate is ruining it. Seems like a real waste to have the house battery only feed the starter. I guess one could bypass it all and run them in parallel but a bit defeating on the purpose. I’d like to be able to run one down using my fridge and Starlink and lights but leave the starter battery alone.

The BMS? No, it's ECU controlled.
The Ctek Smartpass? Yes. That's what @The_Ick posted above.

The BMS manages the starter battery.
The Smartpass manages the aux battery. The aux battery is not visible to the vehicle and is not reported on the electrical page. Owners who want to keep an eye on the aux battery need to put a battery monitor on it.

Your broad choices are:

1. Keep the existing setup and run the house loads from the starter battery. That is what Ineos intended. The BMS and alternator will keep the starter battery charged at the ~80% SOC mark and the aux battery will trickle charge it it via the Smartpass when the engine is not running. If the starter battery gets low the aux battery will boost it via the Smartpass for the next engine start then the alternator will fast charge the starter battery. I have seen north of 100amps charging rates.

2. Install a Ctek D250SE alongside the Smartpass. That will provide a solar panel* input to keep the aux battery topped up when camping and boost the DC charging rate to the aux battery from 120 amps to 140 amps combined. If you're drawing house loads from the starter battery the aux battery will pulse charge it via the Smartpass.
* D250SE solar panel open circuit voltage limit is 23 volts.

3. Run all house loads from the aux battery. Bin the 20 amp Smartpass and replace it with a DC-DC charger. If you get a charger with an EFB profile you can keep the existing aux battery until it dies or just spend more money upfront and swap it out for a lithium battery as @The_Ick said above.

If you want to completely ring fence the starter battery you should also move the INTx and EXTx circuits and the 12v cig socket in the cargo area over to the house battery as part of #3. Some owners have done that and posted about it.

The at-risk owners are those who split their house loads across INTx, EXTx, the fridge socket and go directly to the aux battery (in the factory configuration). If both batteries are being depleted by house loads while parked on a camp site - with the PWR switch turned on - the aux battery cannot assist with an engine start. Pack a NOCO.

 

[Rok_Dr]

Actually the charge rates are other way round @Clark Kent. The DS250 alone has a 20amp charging limit, while the Smartpass120s can charge at up 120 amps. In combination they can charge up to 140amps.

Cheers
Steve

 

[Clark Kent]

Actually the charge rates are other way round @Clark Kent. The DS250 alone has a 20amp charging limit, while the Smartpass120s can charge at up 120 amps. In combination they can charge up to 140amps.

Cheers
Steve

Fixed. And caffeine upgraded.