question

stevensnel avatar image
stevensnel asked

Trickel charge and Orion DC-DC

I’m designing an electrical system for my new van. Mostly I’m doing OK with the resources here and elsewhere on the interwebs, but I am missing a lot on integrating the orion DC-to-DC with trickle charge.

I’ll be using a Multiplus, Smartshunt, VE-BMS, Cerbo GX and Orion-non-isolated.

When camping out for multiple days my starter battery goes flat just from locking/unlocking the car multiple times per day, starting up all the cars gazillion systems every time. I would like to use the 4A trickle charge from the Multiplus to top up the starter battery in this scenario, but am afraid that it will mess with the engine-on detecting from the Orion (Euro 6, smart alternator). Also, won’t this create a 4A loop, between multiplus and Orion, reducing the efficiency of the Orion?

Unfortunately the Orion is not really smart, so the Cerbo is not aware of anything it is doing, correct?

I was thinking to wire the smartshunt-aux to read the starter battery voltage and wire the 4A trickle feed from the Multiplus through one of the relays of the Cerbo. I’m wondering if the starter battery voltage would become available in the Cerbo to set up a rule enabling trickle charge below a certain voltage. Or alternatively, set an alarm below a voltage and switch the trickle feed with a manual switch? In both cases I would still need to make sure the voltage doesn’t trigger the orion engine detection, or I would need to wire the ignition to the Orion and switch the auto charge off.

Am I overthinking this? Are there any resources on setting trickle charge and DC-DC charge up simultanuously?

And a last question: I am allowed to connect both the Smartshunt Aux and the Multiplus trickle feed to the input of the Orion, am I not? No need to pull those wires to the front of the car and connect on the starter battery +?


thanks!





orion-tr smart
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.

6 Answers
Trevor Bird avatar image
Trevor Bird answered ·

If you did want to charge the starter battery via the multiplus you could relay switch the Orion off as it has a on/off function on a connector with a jumper on it. Just pass that through the CerboGx relay contacts if you wanted to.

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.

kevgermany avatar image
kevgermany answered ·

Check the Cerbo relay current rating, I don't think it will handle the trickle charge load.

There's the possibility that the Orion is switching on and draining the starter battery. Worth checking.

Orion will only switch on automatically if the input voltage is high enough. And the multiplus trickle charge is at leisure battery voltage. This may be high enough, depending on how the Orion is configured.

Another way to control the Orion is disable engine on detection and switch it from a switched connection in the car. The switched radio feed is a good option if there isn't one available in the fuse box. Connect the trickle charge as proposed.

6 comments
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.

stevensnel avatar image stevensnel commented ·
Yes, that’s probably the right way to do it. Get a switched connection to the orion. But I would need to use that switched connection to switch off the trickle feed At the same time, wouldn’t I . Or I keep looping electricity between the two batteries?
0 Likes 0 ·
kevgermany avatar image kevgermany ♦♦ stevensnel commented ·
Yes, switch with a relay.
1 Like 1 ·
stevensnel avatar image stevensnel commented ·
Allthough a-parently the Cerbo relay handles 6A up to 30VDC. So the 4A trickle charge should work directly through the unit. I’ll probably use a relay though, switched from the igintion so both systems will never work at the same time. I could still use the CERBO to trickle charge below a cerain starter battery voltage, ensuring that I am only using this when it looks I ‘ll lose starting power.
0 Likes 0 ·
kevgermany avatar image kevgermany ♦♦ stevensnel commented ·
You know the difference between NO and NC relays?
0 Likes 0 ·
stevensnel avatar image stevensnel kevgermany ♦♦ commented ·
Yes, I think so…..why?
0 Likes 0 ·
kevgermany avatar image kevgermany ♦♦ stevensnel commented ·

The battery connections to the Orion will be permanent, not switched. Your relay output will be connected in place of the jumper between the L and H terminals on the Orion. This should be an NO relay. So it closes when the ignition comes on. The Orion will start charging when input voltage gets to the value you configure and the time delay has been met (as per manual) after switch on.

If the Orion is switched off by the relay (ignition off) charging stops and so there's no circular current.

In the engine on scenario, using an NC relay for the trickle charge current switched by the ignition will only allow trickle charging from the multiplus when the engine is off.

Cerbo relays can be configured as NO or NC.

You can also get relays which will connect one set of terminal or the other set. I can't remember what they're called, but one of these would be even better. One side is the DC trickle charge, the other is the one to the Orion LH connections. Wired correctly, ignition off would allow the trickle feed, ignition on would kill the trickle feed and switch the Orion on.


1 Like 1 ·
stevensnel avatar image
stevensnel answered ·

when using the ignition feed and a BMS there is no need for a relay to switch the Orion on and off, is there? According to 2nd picture below I just need to bring 12V to the L , while having the H connected to the ATC from the BMS.


i would then bring the ignition feed also to a standard hella relay and switch the trickle feed from the multiplus via the NO port.

img-3969.jpeg

img-3969.jpeg (407.9 KiB)
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.

goose-f16 avatar image
goose-f16 answered ·

I would also like to know.. I have a vehicle with the renogy DC to DC system and if you put a battery charger on the chassis starter batt, when it hits 13.2v, it kicks on the DC to DC charging in a direct mode where it provides half the amperage to the start and half to house.. its called direct mode.. but if I use the Multipass starter battery trickle, it will likely trigger a loop unless I set the thresholds high.


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.

luphi avatar image
luphi answered ·

I was facing the same issues in my camper van. I have the trickle charge always on and indeed that make the auto engine on detection of the Orion impossible. Then I thought using D+ to switch the Orion. I bought a cheep configurable time delayed relay and configured a delay of 2 min, which was enough between ignition on and engine on. Next issue then was the auto engine off feature of the van. Finally I solved it by using node red and the 2nd relay of the Cerbo to switch the Orion based on speed. This is working reliable now since ~6 month.

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.

stevensnel avatar image
stevensnel answered ·

So, I have another question on the trickle charge: does this work all the time, or only when the multiplus is charging from mains?

1 comment
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.

pwfarnell avatar image pwfarnell commented ·

The trickle charger is taken off the main DC feed to the Multiplus. The Multiplus contains a current limiting circuit and a diode, therefore, it will always be active even when the mains is disconnected. The trickle charger will start to charge the starter battery when the domestic battery is around 0.4V higher than the starter battery due to the diode voltage drop.

When the starter battery is full and taking very little current the starter battery voltage will sit about 0.5V lower than the domestic battery.

2 Likes 2 ·