My gel batteries died, so I finally got around to getting rid of them and swapping in LifePO4's. I decided on a rack mount battery, simply because they had a 10 year warranty, have a seemingly pretty sophisticated BMS and fit nicely in the bay. They are 400 AH's each and I have room for two more. We shall see how they hold up. The big selling point of these battery systems was their ability to integrate with the Victron Multiplus without the need for a separate shunt. I'm still working on that. Apparently I need a special cable. My goal is to be able to run the rear A/C at least 6 hours on battery power. It's going to take some rewiring, which I have not done yet. I just wanted to get these batteries and inverter installed and working before Oshkosh.
At first I thought I would rework the system with a 24 volt inverter, but once I saw how the 12v wiring was integrated into the coach, I decided that was a bridge too far. My impetus on wanting a higher voltage was the fact that I want to be able to run an A/C unit off of the inverter. In other words, I wanted a 5000w inverter, instead of the 3000w, which is the biggest Victron produces in 12v. Instead, I stuck with the 12v Victron 3000. If the one inverter can't handle everything I want to do, I will end up adding another one and probably more battery power.
For now I have the Cerbo and the monitoring screen next to the inverter. I have to figure out how to extend the HDMI cable up into the coach so my monitoring screen can be there. I'm guessing I will end up purchasing a HDMI extender over ethernet, unless somebody has a better idea. Getting that cable snaked up there does not look easy. Hopefully I can use the old inverter "phone" cable to pull a Cat6 cable. Victron needs a better implementation of their Cerbo monitoring screen. I have it remotely on my phone for now.
Thanks especially to Tommy D for posting a picture of his DC-DC charger in the engine bay with everything labeled. A picture is worth a thousand words. Made it a simple hookup after I studied that picture for a while. I will be adding another DC-DC charger but not sure if my alternator can handle it. Is there any way to know how many amps these alternators are capable of? Mine looks original. I was going to swap alternators until I found out the one I wanted was $800. Going to wait awhile on that.
Thanks also to Roger for posting his extensive writeup on his installation. Definitely helped me have the confidence to get this done.
It took a few days of working on this to get it all in place. I still have a few more days to get it all working like I want. But, it does the basics for now, I am just missing the monitoring pieces. So far though, the inverter and batteries seem to be playing nice together.
Kevin
Wow...looks like a costly addition...
Nice system, your going to love it!
To answer your question about your alternator, it is most likely 160amp if it's OEM. One of the main purposes of the B2B charger is to keep the alternator from putting out too high of an output, causing it to overheat. Alternators while they my have a high output, it's not made to be for long periods of time.
Yes,
I understand the B2B charger. The most it will pull right now is 30 amps, which doesn't seem like a big deal. If I double them up, I'm pulling 60, which may be to much for the old girl. I don't want to find out the hard way which is why I will probably swap to a newer, beefier alternator before I add the second charger and start pulling 60 amps continuously.
Kevin
Are you adding any solar? If so that will charge your batteries while you are traveling.
Kevin- Great project, very neat workmanship! These LIFO batteries work very well, their costs are coming down nicely. As Barry mentioned, Solar panels can really add power back as you drive too. I installed a 60 amp Sterling in our configuration, really don't ever use it while driving anymore due to the solar.
I'd be very interested in knowing if you can get the Cerbo display to work with an HDMI extender. I would like o move my display to a more convenient place. Was told by Victron they don't support any form of extension or longer cable than supplied... Hoping you might crack the code.
Best.
JEff
I would suggest getting a DC clamp meter if you don't already have one to measure your existing alternator output (at high idle). The engine and tranny electronics draw power, then add headlights, dash fan on high, and your DC-DC charger on, etc. As Bruce mentioned, alternators can handle max output for short periods but not continuously.
The general rule of thumb I've seen is approx 2/3 of maximum alternator rating for continuous loads. Stated another way, alternator rating s/b 150% of maximum continuous load. So the stock 160 amp alternator can handle say 100 amps for continuous loads.
In my build a few years ago I upgraded to a 300 amp alternator, this will need some beefed up alternator wiring as well.
Extech MA445 True RMS 400A AC/DC Clamp Meter with NCV, green Amazon.com: Extech MA445 True RMS 400A AC/DC Clamp Meter with NCV, green :... (https://a.co/d/aD9FOIG)
Yea, forgot to add that little nugget. I have 2000 watts of solar if I can get it all up there! Might be a winter project at this point. Too many other things to get done in the near future.
Kevin
I read on another forum where this HDMI extender will actually work. It's not cheap.... Amazon.com: AV Access HDBaseT HDMI Extender Over Single Cat5e/6/6a/7... (https://www.amazon.com/gp/product/B019MADOS8/ref=ox_sc_saved_title_1?smid=A33N7O64F8FSDL&psc=1)
I plan on getting the wire ran first. If I can get the Cat 6 cable snaked up through there, I'll terminate it and buy the extender. Might be a while before I get to that also.
Kevin
I have a clamp meter, I will give it a shot tomorrow. I did measure the DC-DC charger already and it was pulling 29 amps just by itself.
Kevin
Another item I forgot to add that this install fixed. I can now plug the coach into a GFCI 120v plug. When the old inverter was installed, it would trip the GFCI every time. No problems now. That was a problem that developed with time. So, maybe that inverter was getting ready to kick the bucket. Not sure.
Kevin