Stop start on new citigo

[Tech1e]

3 hours ago, KenONeill said:

Because, if you don't get compressed air in the cylinder that is on the compression stroke, there will be next to no compression to generate power on the power stroke?

 

A very valid point.

 

I found some info on some trickery using solenoid operated valves rather than camshaft and the ECU will stop the engine at the right point and hold the valves closed so a compressed air state is held. It then injects fuel and sparks and opens the inlet valve.

[KenONeill]

28 minutes ago, Tech1e said:

 

A very valid point.

 

I found some info on some trickery using solenoid operated valves rather than camshaft and the ECU will stop the engine at the right point and hold the valves closed so a compressed air state is held. It then injects fuel and sparks and opens the inlet valve.

Thanks; it sounds like it's "yet another thing to go wrong" then?

[Bobclive2]

Flat battery.

 

Attached is A PDF from Hyundai UK explaining about the AMS system. The text from this pasted below.

 

This model has an engine ECU controlled alternator and this is designed only to operate in a way that reduces fuel consumption and emissions. So effectively it will actually do very little unless it really needs to, which means that until it detects an electrical load from things such as headlamps, HRW etc it will do the bare minimum to charge the battery up. If the customer is only doing those sorts of short journeys and not using any electrical items then the starting of the engine has taken charge out of the battery, but without any electrical items being used it won’t put that much back into the battery again. The Alternator Management System (smart charge) works in a very different way to a conventional alternator. The conventional alternator is charging at all times whenever the engine is running, and will increase its output back to the battery depending upon electrical load and the speed it is being rotated at. In the AMS system the charging function of the alternator is controlled electronically by the engine control ECU based upon various sensor inputs and how the vehicle is being driven, so it can be that the alternator will not be charging the battery at all dependent upon the circumstances at that time. Effectively as the alternator is controlled via the ECU it will only charge the battery when necessary, this is to reduce emissions and improve fuel economy. In certain conditions the system will only charge the battery in small amounts.
So if the vehicle is only used for short journeys, and as the system often does not charge at all after a cold start, if you are only doing low mileage the starting of the engine can take more charge out of the battery than the system will put back in again. This means that eventually the state of charge can be slowly drawn down to the point that although the vehicle will start the ISG will not operate.

 

http://www.talkhyundai.com/hyundaiforumuk/topic/26751-start-stop-isg-and-agm-brattery/

[Emil]

12 hours ago, Tech1e said:

Direct injection puts the fuel straight in... 

No such thing called direct injection in a Citigo. 😆 Only MPI.

[steveeeg]

Thanks for all the replies

 

I took car out for a 20 mile mixed run tonight

 

Car did 1 stop @ traffic lights , rest of the time no stopping due to judging traffic

 

TBH did not feel good to have engine stopped at night with lights and radio on 

 

Quick journey up motorway junction first time on motorway and sat fine @ 70mph and easy up to speed on slipway

 

Reminds me of my 1st car mini 1000 such fun to drive

 

Cheers Steve

[Emil]

You don't have to worry about battery charge. Citigo knows if voltage is low and will start the engine when or if needed. 😄

 

 

[Tech1e]

42 minutes ago, Emil said:

No such thing called direct injection in a Citigo. 😆 Only MPI.

 

The comment wasn’t aimed at Citigo but emerging technology in the industry. 

[Emil]

We were talking about Citigo here. 😉

 

But show me a car with direct injection petrol engine which starts by fuel injected to combustion champer. Oh, and a spark too. 

Edited 6 June, 2019 by Emil

[KenONeill]

So, cutting out all the "smart" and "fuel saving" double-talk, what we're actually saying is that these ECU controlled alternators are not fit for purpose in cars that are used primarily for short urban journeys?

[Bobclive2]

9 hours ago, KenONeill said:

So, cutting out all the "smart" and "fuel saving" double-talk, what we're actually saying is that these ECU controlled alternators are not fit for purpose in cars that are used primarily for short urban journeys?

 

Exactly, same as diesel, no good for short journeys, one more thing, when stop start is not working this indicates a low battery SOC but aircon is still operating, audio and wipers and headlights at night, this will probably take the SOC to an even lower level, it would be interesting to know exactly the limits set for the smart charging system, ie what is the lowest SOC before the alternator is instructed to start charging the battery from engine power.

 

This article below indicates the problems with modern cars and their batteries, (this did not occur before the implementation of stop/start), the article suggests the cause is more electrical draw on these modern vehicle batteries, (“Batteries are not getting adequately charged when driving,” Weber explains. “Infotainment systems and other power hogs are the culprit along with key-off drains.”),  this does not stand up because prior to stop start there were almost as many peripherals drawing current on earlier cars as there are today, standard lead acid batteries were also mainly used at that time. The amount of power drain is irrelevant as manufactures size the battery in relation to all the exrtas offered and are likely to be fitted to the vehicle, A modern alternator is quite capable of providing more than enough current to keep the system running and fully charge the battery at the same time if it was allowed to do so. As said, a simple way to prove this is to fully charge the battery with Ctech charger or similar, disconnect the battery sensor drive the car as normal and see if there are improvements, you won`t have stop/start though but you should have a fully charged battery.

 

Why JD Power Reports 44% More Car Owners Are Having Battery Problems

https://www.forbes.com/sites/jimgorzelany/2017/03/01/why-jd-power-reports-44-more-car-owners-are-having-battery-problems/#158a1566323c    
 

Edited 6 June, 2019 by Bobclive2

[steveeeg]

Sounds like Stop / Start is a bit of a cloudy subject , will have to see how it goes

 

Wanted a new Citigo so did not have a choice

 

Cheers Steve

Edited 6 June, 2019 by steveeeg

[Emil]

On 05/06/2019 at 15:15, Tech1e said:

 

A very valid point.

 

I found some info on some trickery using solenoid operated valves rather than camshaft and the ECU will stop the engine at the right point and hold the valves closed so a compressed air state is held. It then injects fuel and sparks and opens the inlet valve.

Piston rings will leak so it doesn't help even if valves are closed. 

[Tech1e]

4 hours ago, Emil said:

Piston rings will leak so it doesn't help even if valves are closed. 

 

They will have a leak down time eventually but you are talking about stop start not first thing in the morning. 1 minute at the most. 

[Emil]

External power is still needed to start petrol engine. Ignition or combustion cannot start it. 

[Tech1e]

56 minutes ago, Emil said:

External power is still needed to start petrol engine. Ignition or combustion cannot start it. 

 

You seem determined to do believe but the systems are real. 

[Emil]

Just tell me what car have such system. Otherwise stop lying. 

[Tech1e]

5 minutes ago, Emil said:

Just tell me what car have such system. Otherwise stop lying. 

 

Woah there tiger, wind your neck in. 

[Emil]

So the whole story was your own imagination then? And you are telling it is the truth. Nice.

[Bobclive2]

On 05/06/2019 at 09:50, Bobclive2 said:

@Bobclive2 Your posts all make sense in theory. IME the term "smart" preficing pretty much any technology is meaningless, if not actually an oxymoron though.

 

Last post, AGM batteries are supposedly more efficient and should last longer, they are still lead acid, stop/start and smart charging will certainly shorten their lives.

 

4.1 Battery Life Factors The research revealed that the expected life span of a conventional flooded lead-acid starter battery is impacted minimally from the number of starting events. Rather, battery life is mostly impacted by limited charge times between frequent engine start events and from excessive discharge during engineoff events from accessory loads. The length of and the cumulative accessory power draw during each engine shutdown event has a direct and strong effect on battery longevity because of the depth of discharge. If the battery is returned to a full charge between engine starts, the effect on battery life is negligible or nonexistent. Conversely, the battery will fail significantly more quickly if a full charge is never reached. This is true independent of the number of engine start cycles. Also, idling has been determined to not be an effective way to recharge the battery because of low alternator power output; driving is best. 

 

The smart charging system ensures the ICE is not allowed to charge the battery over 75 to 80%, the other 25% must be from regeneration, little or no regeneration ensures a short battery life/.

The study was obviously undertaken prior to smart charging and stop/start but the lead acid battery is still fundamentally the same today as in the study. This means that for a long life the battery has to be returned to a full charge, not kept at 80% or less. You won`t find this honesty in a modern stop/start battery study.

 

https://publications.anl.gov/anlpubs/2015/05/115925.pdf

Edited 8 June, 2019 by Bobclive2