In the Orion XS manual it shows the input for dc/dc to be the engine starting battery with the alternator connected and the output to the auxiliary or in my case the house bank.
This means the alternator charge has to pass through the starting bank before charging the house bank?
Would it make more sense to have the alternator connected to the house bank (LiFePo4) and then use the house bank as the input for the Orion XS to the starter bank. My alternator is 200 amp.
I am planning to install a 920ah LiFePo4 house bank. I can make the engine starting bank a LiFePo4 battery as well or an AGM.
Any suggestions on what would be the right way to do this installation.
The reason it is done the way shown is that most alternators are not designed to charge lithium, they are designed to charge lead acid. They have a single charging voltage of typically 14.5V, lead acid can be kept at this once charged. Lithium must not. Some modern vehicles vary the alternator output voltage down to 12.5V, the lithium would never charge. If the lithium BMS disconnects suddenly the alternator directly charging lithium can get fried. The DC to DC prevents this.
The other solution that I and others have used is to modify the alternator with an external controller such as as Wakespeed WS500 or an Arco Zeus which can then control lithium charging properly. The alternator usually requires internal mods.
The traditional way is to guard the alternator from the low resistance lithium batteries, i.e. connect the lead batteries to the alternator, charge the lithiums over the dcdc unit.
Switch the dcdc on with either ignition or d+ connected to the h signal input, leave the l open.
The alternators I am using from my main engine and my DC generator, both use external alternators. I currently hav Balmar MC-214, but looking at changing to the MC-218. The 214 is extensively user programmable, however the MC-218 has a lithium program. I looked at the Arco-Zeus Zeus and the Wakespeed WS 500. Those look really cool, pricey to buy 2 of them.
I believe both of my alternators has protection for accidental disconnect. I am not opposed to running the alternator through a lead acid starting battery. My main question with that is: Will the voltage regulator see the fully charged lead acid and not give the lithium everything it can take? Or will the Orion XS make sure the regulator can see the acceptance of the lithium batteries?
Ludo, Thanks for your reply. I have not purchased the Orion XS test, but I did read through the manual twice. I made reply above to pwfarnell’s comment.
I am a little confused with how the Orion turns on (the ignition makes sense, however I have a generator and a 50hp Perkins). What is the d+ connected to the h signal input, leaving the I open do?
Also I have a 400watt wind generator that uses a custom built charge controller, it will divert energy to a ceramic heat sink when the batteries are fully charged. When it switches from divert back to the batteries (specifically if the wind is blowing 25+ knots) it could potentially cause a 400 volt spike for a few seconds. This would be absorbed easily with a lead acid battery, but could be problematic with a lithium. I was told this detail by the builder of the charge controller. I will probably buy a new charge controller made for this unit to work with lithium, however, I could use the same charge controller and connect the wind generator to the starting battery that would then be connected to the lithium. I’m thinking this should solve the potential voltage spike issue.
Like any set up, if the battery is full and the alternator regulator is at its max voltage, any load on the system will reduce the voltage a bit causing the regulator to increase the current to recover the voltage, thus supplying the load. So yes, it will work, which is why Victron show it like this.
The only issue I’m having with this set up is my alternator can put our 200 amps and the Orion XS is only capable of 50 amps, so I would have to use multiple units. Is that correct?
Your alternator is good for 200A, but only for a short time, then it will derate. Start with one xs, have an eye on the alternators temperature, you can always add a second later.
When the Orion XS is hooked up DC to DC does the charge amperage/voltage only flow in 1 direction? Example if the alternators are connected to the AGM starting batteries, but the solar MPPT and wind generator regulators are connected to the lithium bank, can the solar/wind charging get to the starting bank?