Help design my adventure van power system please

djb_rh

Observer
Cool stuff, Just dont follow his example of crimping ring terminals !

Got a pointer to your idea of the right way? (Not saying you're wrong, just curious what you mean. I'm probably going to need to buy things to crimp stuff this big.)


--Donnie
 

dwh

Tail-End Charlie
Got a pointer to your idea of the right way? (Not saying you're wrong, just curious what you mean. I'm probably going to need to buy things to crimp stuff this big.)


--Donnie

I think he means don't put it on the concrete and smash it flat with a hammer.

To do it right there is the expensive hydraulic crimper, or the cheap bang it with a hammer crimper.

Personally, I use the "drop by the welding supply shop" method. The right shop has the cable on spools, a selection of terminal types, the proper crimping tools and experience. All I have to do is give them a list of the lengths, sizes and terminals and come back the next day to pick up the order.
 

java

Expedition Leader
And use adhesive shrink tube!!! Its wonderful stuff.

Harbor freight has a ~$60 hydraulic crimper that gets good reviews.
 

djb_rh

Observer
So I'm plenty competent at soldering small electronic things. Competent at soldering medium sized things with a soldering gun. Never soldered anything quite this big. I assume it's pretty easy just using a small torch, though? I mean I definitely know how to tell when it "takes" versus it's just sitting there and whatnot.


--Donnie
 

dwh

Tail-End Charlie
Soldering is second choice. A proper crimp is better.

But as to how to do it...

Know how to sweat copper pipe? Same technique.
 

djb_rh

Observer
Getting a little annoyed at Peter Kennedy. He's "designed" a system to my specs including block diagram, but now goes MIA when I ask multiple times "so how do we get this turned into an order?" *sigh*

Time to look for other vendors, I think.


--Donnie
 

djb_rh

Observer
So, finally got in touch with Peter and worked everything out. Here's the component diagram:



Going with the 3000W inverter. It's a couple hundred more bucks, but is actually physically smaller than the 2000W by a chunk, so well worth it. Also going with 2x200A batteries. The first order will have all the above plus a few options, then I'll still have to do a second order with cables once I know lengths and such. But the above is the stuff likely to have annoying lead times and has to come shipped freight.


--Donnie
 

djb_rh

Observer
$55, and use one of their ubiquitous -20% coupons to make it $45.
https://www.harborfreight.com/hydraulic-wire-crimping-tool-66150.html



eta and djb, any consideration of a smaller second inverter to 'right size' and up your battery efficiency, as opposed to running a huge inverter for a small load?

Thanks for the crimper recommendation. As for the inverter, yeah, there are a lot of times where the one thing I'd need would be my laptop power brick since AFAIK there's no DC supply for Macbooks. But maybe there is and I should check. If not, using a small inverter just for that probably makes sense. I'm guessing the Victron inverter is pretty good, though. With all this monitoring, I should be able to find out easily if it's worth having a smaller inverter or not.

Either way, if I do that's a cheap and easy add, so good idea to look into it.


--Donnie
 

Rando

Explorer
This looks like it is going to be one really nice power system. One question - what exactly is the Cyrix charge relay for? I just set my MPPT charger up for LiFEPO4 chemistry and forgot about it. One comment - you should confirm that there is some sort of low temperature cut off in the system. One of the drawbacks to LiFEPO4 chemistry is that you really shouldn't charge the batteries below 0C. Maybe I just answered my question about the Cyrix charge relay.
 

rayra

Expedition Leader
Think of it also as redundancy. Two is one, one is none. You want to have some 'fault tolerance' in your setup. Even 'quality' parts fail occasionally.
 

djb_rh

Observer
This looks like it is going to be one really nice power system. One question - what exactly is the Cyrix charge relay for? I just set my MPPT charger up for LiFEPO4 chemistry and forgot about it. One comment - you should confirm that there is some sort of low temperature cut off in the system. One of the drawbacks to LiFEPO4 chemistry is that you really shouldn't charge the batteries below 0C. Maybe I just answered my question about the Cyrix charge relay.

In my conversations with Peter, he mentions a temperature sensor that's not shown in the diagram he sent me, so I think this is covered. In any event, it's SUPER unlikely my batteries will see 0C anyway. Good mention for others who might be following along, though!

As for the Cyrix charge relay, my understanding is LiPo's shouldn't be charged any longer once completely full. The Victron batteries literally pass a message that they are now full and that relay gets the message and shuts off completely. If you're not using Victron batteries, I'm guessing the MPPT has to do a bit more of an educated guess about what "full" is. It's probably "pretty good" at that educated guess, but this is probably a bit more ideal.


--Donnie
 

DiploStrat

Expedition Leader
N.B. Victron sell two models of their Cyrix intelligent relay. Be sure you get the model with the settings for LiFePO4.
 

djb_rh

Observer
N.B. Victron sell two models of their Cyrix intelligent relay. Be sure you get the model with the settings for LiFePO4.

I'll check, but hopefully this is what Peter Kennedy is doing for me. Making sure all this works.

I found a better description of the reason for the relay on the MPPT output. The MPPT only has one bus connection, and if you want to be able to monitor the MPPT with the Color Control GX (which I do), you can't have the batteries tell the MPPT when they are full. So they tell the relay instead.


--Donnie
 

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