question

mixingwizard avatar image
mixingwizard asked

Dual Alternator Confusion

Hello all,

I've managed to utterly confuse myself and could do with some advice.

I've just upgraded my leisure batteries to lithium and am trying to figure out a method of charging them.

I have two alternators - one smaller one charging the lead acid starter battery and one 80a one to charge the leisure batteries (304a DIY lithium battery). I have an Orion 30a which I was hoping would solve the issue but I've come across a few problems.

Firstly I can't get the Orion to pull current directly from the alternator without also connecting it to the starter battery. Is this likely to cause me any problems as I would then effectively have two different alternators going into the Orion?

Secondly, I currently have the inverter (an older Multiplus Compact) hooked up in parallel on the leisure battery - this is fine when the engine isn't running but limits my current to 30a when the Orion is charging - is there a way I can pull from the alternator directly while charging but have it seamlessly switch back to the batteries? It also causes lots of alarms on my inverter for some reason.

I'd appreciate any input from someone more experienced!

Thanks,

MixingWizard

Lithium Batteryorion dc-dcalternator
2 |3000
Toggle Comment visibility. Current Visibility: Viewable by all users

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

2 Answers
Kevin Windrem avatar image
Kevin Windrem answered ·

The input to the Orion can't come from the alternator alone. There needs to be a battery there. The alternator expects that also.

Another option would be to use an alternator controller that can directly connect the alternator to the leisure battery. The risk of this connection is overloading the alternator. I recall a video from Victron showing one such controller and how it limits current based on temerature.

2 |3000
Toggle Comment visibility. Current Visibility: Viewable by all users

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

Trevor Bird avatar image
Trevor Bird answered ·

@MixingWizard if you want to use two alternators simply use one to charge the start battery and use the other one to charge the leisure batteries. Instead of using the orion, consider using an external regulator for the alternator charging the leisure batteries. The external regulator will handle the correct charging of the lithiums as it is programmable. It does need a temperature sensor to be attached to the body of the alternator to back off the charging if the alternator gets too hot. unfortunately the Orion is not the product you were looking for for this job.

The orion would be good if you had one alternator and you wanted to charge the start battery from the house bank but you have two alternators so an external regulator is what you really need.


2 |3000
Toggle Comment visibility. Current Visibility: Viewable by all users

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 DC to DC Converters Product Range

__________

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?