Umbau (T6.1 California Ocean MJ2021) auf 2*Lithium 105AH (LiFePo4)

[jmstockholm]

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Thanks a lot for the effort!

[jmstockholm]

@Tim_Jochen hmm, I wired the dc/dc charger, completely removed the VW original battery shunts and hooked up the LiFePo4 batteries as well as the starter battery and connected shore power, but can't detect any increased voltage from the charger on any of the fuses (the dcdc doesn't kick in either as incoming voltage is to low).

 

The CU battery display is reporting 100% charge and reports the voltage from the starter battery (12.7 if I remember correctly while the LiFePo4 is at 13.1). My theory is that as the starter battery is 100% charged thus the CU might not give the charger signal to start, but I don't know.  That leaves me a bit stuck as I can't identify the fuse by measuring the voltage increase over the fuses while on shore power.

 

Well, I might have to mount everything, drive for a while and then dismount the drivers seat etc. and have a go at it again.

 

But, do you have any more information that might be useful, if my theory is correct and anything else I could do find the fuse? I have my hands on the circuit drawings from this forum, but unfortunately they don't cover the endpoint of the charger output... 

Bearbeitet vor 18 Stunden von jmstockholm

[Tim_Jochen]

Hallo @jmstockholm, 

ich schreibe mal in deutsch weiter, übersetzen ist ja vermutlich kein Problem. 

 

Wenn du derzeit Landstrom anlegst, hängt ja noch die Bordbatterie, die LiFePo4, am Ladegerät - das sieht die 13,1 V, da ist eine AGM mehr als voll. Das könnte erklären, warum es nicht anspringt. Zeigt die CU, dass Landstrom angeschlossen ist, mit der orangenen Anzeige? 

 

In der CU - das kenne ich allerdings nur vom 2020er Beach Camper - wird nur die Spannung der Bordbatterie angezeigt, wie kommst du zu den 12,7 V der Starterbatterie? 

 

Du könntest an die Bordbatterie einen starken Verbraucher hängen, dann müsste die Spannung im Bordnetz fallen und das Ladegerät bei angeschlossenem Landstrom anspringen. Also z.B. am Wechselrichter einen eBike-Akku laden und gleichzeitig Kühlbox oder Standheizung nutzen. 

 

Eine andere Idee: zumindest im Beach Camper geht von der Sicherung die Leitung direkt zur Bordbatterie, landet dort auf dem Plusverteiler als vergleichsweise dünnes Kabel (es geht ja nur um 15 A). Danach könntest du auch suchen. 

 

Mal sehen, ob mir heute Nacht was einfällt, viele Grüße, Jochen 

[jmstockholm]

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[metalmax83]

Additional (possibly useful) information: the fuse for the wire going from charger to starter battery IS NOT under the driver's seat. That's only the case for the Beach model. In the Ocean model, it should be found in the fuse box below the cup holder in the middle console. 

The fuse for the wire connecting charger and camping battery IS under the driver's seat, just like in the Beach model.

[jmstockholm]

@Tim_Jochen I solved it!

Firstly, you are correct that the CU (only) displays the house battery voltage, I checked again.

Secondly, when I re-installed the AGM battery the charger kicked in when connected to shore power, thus I could identify the fuse. On mine 2023 Ocean it was the fuse indicated in the picture, denominated SH14, which actually reconcile with the information: 14 - 30AOnboard charging unit -A11- in this link: 

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 (however I have also seen SH11 mentioned in a service manual for the Cali, so it looks like it can vary).

 

Thanks a lot for your support!

 

Pictures: fuse in place - charging. Fuse pulled, drawing current from battery while still hooked up to shore power.

 

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