[bj96]

Originally Posted by saket77

.... detect it as a 6V battery and will cut off charging as soon as the battery voltage is around 6 volts... I had to use an old battery charger to at least pump some charge in the super low batteries till 8V so that the C3 could identify it as a 12V battery...

Here is trick- get another 12v battery (size doesn't matter), or 12v LED driver and put it parallel to the weak battery terminals while connecting the Bosch charger. Latter will "sense" the 12v across terminals and start charging pronto. At this point disconnect the extra aid, Bosch will continue charging. I've fooled the Bosch several times like this :-)

Cheers,
-BJ

[gsratta]

I have been planning to get the Bosch C7 charger since a long time, but always questioned myself if spending around ₹6000/- was really worth it. Due to some personal reasons my driving has reduced in recent months, and my car remains stationary for upto two weeks sometimes. So I had kept it in my amazon cart. Today just took a look at the price, and I couldn’t believe, it was, rather it is just ₹2742/- for the C7, so for those who were sitting on the fence, now it is the time to get it.

[wildsdi5530]

Originally Posted by gsratta

so for those who were sitting on the fence, now it is the time to get it.

So my AGM battery is about 8 yrs old. Original Varta, mercedes branded. Of late the auto stop start is not working and I have been on the fence regarding new battery vs this charger. The resting voltage is 12.8 and dips to 10.9 on cold start. Had reached out to Swastikfabs but they are unable to figure out which battery is installed base on the pics.

Took the plunge yesterday the charger arrived today. It is 2020 packed, but otherwise seemed fine. Disconnected the battery and charged for 4 hrs on regen mode. Auto start stop had started working again but stopped after 3 kms of driving. Guess I will have to buy a new battery.

[DDIS_RE650]

The Bosch C7, one of the best car tools has been stolen. It seems that it was taken away by the Dash Cam installation person. I have used it to charge the battery of Ertiga, Interceptor, and Activa. It is a perfect device for any emergency usage.

Do I need to buy the same or can get a local charger (well built and good configuration)?
Please advise if anyone is using a locally assembled car charger.

[vidyanand]

DIY Quick Connector for Bosch C7 (and C3) Car Battery Charger

I needed an extra quick connector to charge my TVS Wego, which has limited use for local errands and would often get discharged by sitting idle. The battery is difficult to reach compared to a car. You need to unscrew 4 bolts to remove a panel and then pull out the battery to access the terminals to clamp. The quick connect harness for Bosch C7 would take care in avoiding this easily.



Although searching with the part did result in Amazon listing but was never available Bosch C75AC0 Quick Connect Cable Harness for C7 Battery Charger with Built-in Cable Fuse. I shot an email to Bosch customer service which was of no help. They redirected to check with local Bosch Car service center who never had this product. So eventually decided to go the DIY way as earlier suggested in the thread.

Items needed:

• XT60 connector pair - 1
  
  
• Electrical Wire Crimp Terminals Connectors 4-6 sqmm (this is same size as in the C7 charger) - 4
  
  
• 1.5 sqmm wires - needed length in pair
• Shrink Wrap
• Soldering Kit

I had all items available at home except the connectors. XT60 was ordered on amazon while the battery terminal was sourced from local electrical shop.

Task is simple, make two sets of the XT60 -to- Battery Terminal Connector. One with Male one and the other with Female XT60 connector. Pics to clarify.







One set needs to be attached to the C7 clamps.







Fix the other set to your car (or scooter ) battery terminals. I fixed in scooter and routed to the storage compartment for easy access. Shrink wrap/zip tie the cables together along the length as needed so that they do not move around. I made a small hole to let the cable in the compartment. Missed taking the battery terminal connected pic (will request mods to attach later when I access the battery in the future).




That is it. Just pop up the seat (hood in your car) and connect it to charge multiple vehicles as needed. Just add one set for each vehicle, making sure that the all vehicles must use the same connector end (Male or Female) while the C7 attached is opposite end. XT60 can be bought individually of all Male or all Female as needed.

Significant Pointers

• Can use any such easily available connector pairs, e.g. XT90 or other.
• The connector has +ve and -ve marking to make it easier. I used blue wire for negative and red for positive.
• Connector already soldered with wire are also available in case you want to skip soldering. Simple connect or crimp will ease the job.
• Battery Terminal ring that I used was perfect for the 12V battery in Wego. Do check for size if you car battery has bigger terminal bolts. I went with the ring size in C7 kit assuming this would work.
  
• This is not water proof at the connectors without a cap. One can choose a water proof connector set, if available.

To reduce risk, I kept the the connector with the cavity attached to C7 clamps while the one in scooter would not accumulate water. Additionally, I used a USB-A Terminal cap to mold as a cap in the scooter.


That's all folks, hope it helps since Bosch did not make this part available to buy for users with multiple vehicles to charge.

[DDIS_RE650]

One query, do we need to remove the terminals( both +v and -ve) before charging the battery by C7 charger?

[vidyanand]

Originally Posted by DDIS_RE650

One query, do we need to remove the terminals( both +v and -ve) before charging the battery by C7 charger?

This is Not needed at all. The charger is supposed to used in as is setup.

Infact, removing the battery terminals will cause much harm to modern German cars and general inconvenience with older cars, i.e. reset time while loosing on your trip detail histories.

[DDIS_RE650]

Originally Posted by vidyanand

This is Not needed at all. The charger is supposed to used in as is setup.

Infact, removing the battery terminals will cause much harm to modern German cars and general inconvenience with older cars, i.e. reset time while loosing on your trip detail histories.

Thank You, the car in question is Ertiga ZDI. Does it also apply for Motorcycle (RE Interceptor)?

[Mortis]

Originally Posted by DDIS_RE650

One query, do we need to remove the terminals( both +v and -ve) before charging the battery by C7 charger?

You would only need to disconnect the battery terminals if you were doing a repair charge cycle.

[dijkstra]

In my case, I need to disconnect and carry the battery home to charge it. The garage is a few hundred meters away from my house.

I have noticed that disconnecting the battery reduces my milage somewhat for the next 100ish Kilometers (13kmpl vs 10kmpl) - I guess the car computer forgets the fuel trims? This has also happened both the times I had to send my car to the bodyshop to fix dents (they disconnect the battery).

If I had a choice, I'd charge it without disconnecting.

[1.2GT3GT]

Originally Posted by R2D2

If the voltage is <9V the battery is probably a goner which is why the charger isn't turning on. To attempt a recovery connect it to your C7 and select the power supply mode which is indicated by a power adapter symbol. To do this press the Mode button for 3-4 seconds. That sets the voltage to about 13.6 V which will raise the battery voltage in due course. Once it reaches >12V you can switch back to the normal mode of operation. Do not leave the battery connected and unattended for very long when the charger is in power supply mode. It may boil off the electrolyte.

Just had a look at the Bosch C7 documentation. The documentation mentions that the ‘R’ mode should be used for regeneration purpose. The documentation also mentions that the battery should be disconnected from the car when attempting the ‘R’ mode.

The ‘power supply’ mode seems to be for just that purpose, to use only as a power supply and not for regeneration. Also when in ‘power supply’ mode, the reverse polarity protection feature is not available according to the documentation, so that’s another point to note.

[R2D2]

Originally Posted by 1.2GT3GT

Just had a look at the Bosch C7 documentation. The documentation mentions that the ‘R’ mode should be used for regeneration purpose. The documentation also mentions that the battery should be disconnected from the car when attempting the ‘R’ mode.

The regenerate mode is a bit of an iffy thing and does not work smoothly with dead batteries. It throws an error basically suggesting a battery replacement. Hence to fool the processor we shift to power supply mode to bring the battery voltage to approximately 10v and then shift to normal charging mode.

The reason why you need to disconnect the battery from teh car to use R mode is because it delivers voltages as high as 16V which could damage some sensitive car electronics.

I sometimes use a 'dumb' charger without a processor to charge at a constant voltage of about 15V to kick a flat battery to life. These smart chargers can be a hindrance at times.

The ‘power supply’ mode seems to be for just that purpose, to use only as a power supply and not for regeneration. Also when in ‘power supply’ mode, the reverse polarity protection feature is not available according to the documentation, so that’s another point to note.

The power supply mode is essentially to power memory banks in the car's electronics for e.g. the seat position, radio station memory, clock time etc and is used as a temporary arrangement till the recharged or a new battery is fitted in the car.

I also use it to bypass the processor and charge a totally flat battery. Just some jugaad. IIRC there is a time limit to how long you can use the power supply mode. Bosch clearly cautions the user "Caution: To avoid possible destruction, never charge the battery for a lengthy period in this mode." on page 8. So only use this mode to charge if the battery does not seem to respond to the charger and the normal charge or R charge cycle fail.

[1.2GT3GT]

Originally Posted by R2D2

The regenerate mode is a bit of an iffy thing and does not work smoothly with dead batteries. It throws an error basically suggesting a battery replacement. Hence to fool the processor we shift to power supply mode to bring the battery voltage to approximately 10v and then shift to normal charging mode.

The reason why you need to disconnect the battery from teh car to use R mode is because it delivers voltages as high as 16V which could damage some sensitive car electronics.

I sometimes use a 'dumb' charger without a processor to charge at a constant voltage of about 15V to kick a flat battery to life. These smart chargers can be a hindrance at times.



The power supply mode is essentially to power memory banks in the car's electronics for e.g. the seat position, radio station memory, clock time etc and is used as a temporary arrangement till the recharged or a new battery is fitted in the car.

I also use it to bypass the processor and charge a totally flat battery. Just some jugaad. IIRC there is a time limit to how long you can use the power supply mode. Bosch clearly cautions the user "Caution: To avoid possible destruction, never charge the battery for a lengthy period in this mode." on page 8. So only use this mode to charge if the battery does not seem to respond to the charger and the normal charge or R charge cycle fail.

Thank you very much for the additional context and practical information. It is much clearer to me now.

[saket77]

^^ I had written about the trick to recover a dead battery with these smart chargers back in the day. Hopefully someone will find it useful, hence posting the link again:

https://www.team-bhp.com/forum/techn...ml#post4853847 (Ownership Review: Bosch C7 Battery Charger)

[Scarlet_Rider]

Has the Bosch C7 charger been discontinued? It's not listing on Amazon and Flipkart. Not even on the Bosch India website.