Hi All - I have had a new Orion XS fitted to my motorhome and it never does more than absorption charge to my 230A Fogstar under seat Lithium leisure battery. The battery has gone as low as 21% SOC and it makes no difference, it just stays in absorption doing abou 4 Amps. On a 2 hour drive with the fridge being powered by the battery I end up running the lithium battery down rather than it charging! On start up the history shows a few seconds in Bulk and then switches to absorption where it stays. I have a Euro 6 engine so presumably a smart alternator.
Battery Setting on the Orion is Smart Lithium and uses the defaults for that:. Absorption V 14.2v float and storage 13.2v.
This just does not seem right to me - any advice on what to check?
Some pics attached showing the data while driving.
You probably have too low an input voltage, what is your engine shutdown voltage. If the input voltage falls to the input voltage it pulls back the current to stop it falling lower. This is described in the manual. This is one problem with Euro Smart alternators, again there is w whole section on these alternators in the manual. 2 options, reduce your shut down voltage to 12.9V minimum which will still ensure you do not overdischarge your battery or connect to the ignition switch.
On my caravan system the charge current is limited by the smart alternator/wiring. I have never seen more that 5 amps and that’s with no control gear in the charge circuit.
Never got to the bottom of why as the fridge is on a separate feed and in practice all my needs are covered by the caravan solar.
Could It be the alternator limiting the charge current as mine does? I know in theory the battery will take full alternator output but in practice that doesn’t seem to happen in a vehicle.
One thing about my alternator, with no caravan attached it only charges when the engine is not “working" such as on overrun/engine braking. The voltage is normally at 12.6v and goes to 14.4v when this happens.
When the van is attached it stays at a constant 14.4v so something in the Trailer Control Module which controls the trailer lights etc is telling the alternator there is a van on the back.
I’m afraid smart alternators are a bit of a black art as far as I’m concerned.
@JohnP On further reflection, I think your issue is do do with your wiring between the Orion XS and the battery. The Orion XS says the output voltage is 14.2V, which is its configured voltage for lithium, so the Orion is getting to the charging voltage so it is working properly, the problem is the voltage is not getting to the battery terminals if the SOC is low and it is not charging. Check all your connections, fuses, breakers, isolation switches including the negative ground wire and make sure both battery negatives have a good common connection. It is best to do these as direct wiring rather than the chassis. If you have a multimeter check the voltage at all connections to try and find the rogue one. Do you have one of these no name cheap breakers, they are rubbish and often cause high voltage drop.
So I’ve now had time to check the voltage between the Orion and leisure battery. It’s seems fine, 14.1v all the way, either side of the fuse and at the positive terminal on the battery.
Looking at the Input Amps to the Orion from all my screen grabs since it was installed I now realise that the Input Amps never gets above 5 and is typically about 4. The Output from the Orion is always slightly less than the Input which is correct I think. So… I am thinking that there is something wrong with connection between the Orion and Starter battery?
Alison, and please excuse my ignorance- how does the Orion know what the SOC is of the Fogstar battery and therefore how does it know when to go into Absorption etc? Any comments gratefully received.
I did see that one part of the cable between Orion and Fogstar looked a bit squashed but as noted above this doesn’t seem to impact the voltage at the battery. Picture of the cables going into the Orion attached. I note that the Input cable is thinner than the output. Does this matter?
The Orion does not know the SOC value, how it changes between bulk and absorption is voltage, if the Orion batteryterminal voltage comes up to 14.2V, bulk is over and it switches to absorption and starts limiting the current as the last few % goes into the battery. It only stays in absorption for a short while. If it is going to 24.2V on the Otion and the battery terminals then rother the battery is full and the SOC is wrong, or the BMS has a high resistance or a connection inside the battery. I doubt there is a problem with the input wiring if the battery terminals are st full voltsge, the battery is limiting charge. Have you spoken to Fogstar.
Thanks. It’s a puzzle but your input is really helping. I have contacted Fogstar today. Just two more screen grabs to add to the story that could indicate a BMS issue as you suggest. All taken at the same time from which it’s clear that the battery is depleted to a level that should allow a bulk input and the battery voltage is a lot less than the output from the Orion indicates if that means anything! The additional few Amps are from solar input.
Nothing wrong with the Orion, either wiring between the Orion and the battery or inside the battery. If as you say the battery terminals are 14.2V then it is inside the battery, if it was wiring the battery terminals would be 13.1V.
