kimmaxim avatar image
kimmaxim asked

DC-DC Charger LifePo4 BMV 700 Setup help

Hello Hello!

My name is Kim and i'm from Berlin, Germany! I build a 2018 VW Crafter with two batteries from the factory into a Camper-Van. I used a Lifepo4 Amperetime Battery with 200ah (as a third battery mostly for the complete camper stuff), which I want to charge during driving via alternator with a 12/12-30 Orions Smart or via shore power with the Victron Blue Smart 12/30. I'm monitoring it via the Victron BMV 700.

I'm having several problems with the settings so first of all, the BMV 700 shows pretty much complete wrong settings. For example the fridge runs with 50w and the BMV only shows a maximum of -21w. If it Charges via the Blue Smart there are around 400w outgoing into the Blue Smart and the BMV 700 only shows +160w. I tried to figure out what the correct settings are for the LifePO4 and i tried to set it up, but its never getting better. Plus when im not charging at all, it always shows around +2w. The battery never discharges, im always between 100-90% last time all my power went off when i should have still been via bmv 700 at 90%. I tried to type in the settings from the battery manufacturer but it's not getting better.

Then probably my biggest problem, the VW Crafter has an Intelligent Alternator, when im driving in normal speeds its constantly changing the voltage. When im not using a lot like, heated seats, ac on full power it sometimes falls down to 11.6v. Now I monitored it during my last drive it should be ok, when I set it up for the engine shut down to around 12.5v. But what i*m thinking is, if I set it to 12.5v it will drown my factory batteries, because they have when the engine is shut off around 12.8-13v. Maybe my Orion is broken, I thought the exact reason why you buy such a Orion DC-DC charger is so the smart alternator still powers up the voltage so the Orion can charge my lifepo4?

Maybe somebody is out there who had a similar experience with a smart alternator, ampertime battery and victron stuff! Would be great to get some help!

Thank you in advance!

BMV Battery MonitorLithium Batteryorion dc-dcsetup
2 |3000

Up to 8 attachments (including images) can be used with a maximum of 190.8 MiB each and 286.6 MiB total.

2 Answers
kevgermany avatar image
kevgermany answered ·

BMV - this is a battery monitor for a single battery bank. It measures current through the battery negative terminal, but not current which does not go through the nattery. ZB If your fridge is running at 4A and the Orion is charging at 10A, 6A will go to the battery and the BMV will show only 6A. Guessing you have the BMV shunt and battery wired incorrectly. The LiFePO4 battery negative must only be connected to the battery side of the shunt. Any other connection must go to the load side of the shunt. Especially chassis ground. When this is correctly cabled, you can follow the zero current calibration in the manual if it's still needed.

Orion - you can usually tune the settings around the smart alternator. If you cannot, turn off engine detection, follow the manual to switch it on and off with the LH pins. There will be free connections in the wiring that are switched by the ignition. An easy to find one is the switched radio connection.

2 |3000

Up to 8 attachments (including images) can be used with a maximum of 190.8 MiB each and 286.6 MiB total.

kimmaxim avatar image
kimmaxim answered ·

Hello Kevgermany,

thank you for your respond! So after checking, I figured out it was an incorrect wiring.. i fixed that and now it works.

+ The alternator of the crafter only falls under 12v when I have the engine running while standing. So I tuned the settings so now I might have figured out a way, I'm happy! I also tested the version with the LH pins. if it wont work out the way it is now, I will pull a cable from the ignition on signal to the LH Pins.

Thank you for helping me out here!

2 |3000

Up to 8 attachments (including images) can be used with a maximum of 190.8 MiB each and 286.6 MiB total.

Related Resources

Additional resources still need to be added for this topic

Victron BMV battery monitors product page

Additional resources still need to be added for this topic

Battery Compatibility

Did You Know - How to create a battery profile for non-Victron batteries?