We have a 1200 amp hour Iion house bank monitored by our victron, smart b m v. The autogenset controller is a xantrex module that interfaces with our 3kw zantrex, charger inverter.
We can set when to start and stop the generator based on many parameters. However, we do not have the capability of inputting state of charge.
We would like to start the charger at about 30% state of charge. And stop it several minutes after the charge is full. Thanks for your help.
Hi. Apart from the BMV, what Victron gear do you have?
Thanks Nick. We have a BSC IP 22 12/30/3 for port,starboard and generator agm start batteries. We have 2 DC-DC 12/12/30’s. Port and starboard alternator charger/regulator. Non isolated. Used to charge excess current to house while underway.
David O’Connor
561.386.2692
Do you have a GX of some variety?
No, we would upgrade but we haven’t seen an auto gen start yet. We keep using the older Xantrex 3kw invert and 150a charge
They built in a custom battery menu in anticipation of LiOn. So my bank is meeting the bank specs along with your smart BM. We in the Bahamas for a couple of months and we anchor out alot.
When looking at my charge profile, I think I should pick something like start gen to charge: 12.7V for 15 secs. Stop gen: 14.2V for 10 mins.? It takes me1 hour per 10% SOC. Thanks for your time.
David O’Connor
561.386.2692
The GX device has a sophisticated generator control system but without a VIctron inverter it may not be worth the expense since it can not integrate with your Xantrex inverter/charger.
The BMV 700 and BMV 712 have a programmable relay output that can be set to a range of SOC along with other parameters like battery voltage. If there is an input to your generator control that can accept this as a “close to run, open to stop” signal then this is probably your least expensive solution.
A better solution might be to replace the Victron BMV with a battery monitor that integrates with your Xantrex control system. Then hopefully it’s generator logic will accept SOC from that.
(Or get a Victron inverter)
Perhaps get the CerboGX to take advantage of the generator autostart feature and use the BMV to trigger the CerboGX based on SOC. The BMV is measuring the current used by the inverter so a native interface to the inverter is not required to use SOC as the trigger for generator functions.
Thanks much for your expertise.
I need to upgrade to the Victron charger inverter product line before my old xantrex dies. I haven’t spent enough time researching my options.
I think I can make the relay start stop from SOC work. I’ll do that at the dock in a couple weeks when we get back.
In the mean time is there a way to convert SOC 35% and Full to a start / stop Volt value? I suggested some values in my 1st post based on my charge history.
If you guys have a Victron configuration recommendation for me I would appreciate it. I’d like a 200A charger and 3Kw inverter combination , depending on space requirements. Solar input with remote monitoring. Camera and bilge water alarm. Thanks again for your valuable time. David.
@Davidfrancisoc . I have a Xantrex inverter in my boat and while I would replace it with a Victron if it failed, it has served me well for 13 years and does a great job. All good if you just want to swap out the inverter because you want to but don’t do it because you fear it will fail as from my experience that is not a highly likely scenario.
The short answer is yes to a correlation between SOC and battery voltage in steady state but it is dependant on each battery and under normal circumstances SOC is a more reliable method of generator control.
The inverter is one part of your DC system. You have many other things that can charge and discharge your batteries. Your inverter can, but shouldn’t necessarily control your generator auto start unless it is the only load on your batteries.
If you have a CerboGx and couple to the BMV you can reliably control the generator. Please review the extent of the CerboGX abilities. It is just such a wonderful device because it is just so powerful. Even if you use a very small fraction of its capability you will get good value.
