Schematic Rev 1 Review Please!

[rafrojack]

Hi fellow van nomads,

I've been knee deep in analysis over my electrical system for my van. Please take a look at the attached picture & let me know what needs to be changed! I've placed questions that I'm worried about in the same graphic. Positive criticism is needed! My main wickets to hit are:



1. More than enough power for two people.



2. Most up to date configuration on theory & parts.



3. Great quality parts & workmanship. Also, minimum # of parts/wiring without sacrificing safety & workmanship.



4. Shore power access & alternator b2b charger for emergencies.

Attached PDF in case you cannot zoom in well in enough.

Thank you for coming to my TEDVanLife talk.

 

[TCgreg]

Looks pretty good.

Lithium batteries typically don't use a temp compensation for any chargers. Battleborn specifically clarifies no temp compensating which could cause the BMS to shut down charging. Unlike traditional batteries lithium accepts a good charge under a wide variety of temperatures.

https://battlebornbatteries.com/wp-content/uploads/2017/09/Battle-Born-Manual.pdf

Personal preference but I prefer to have a master battery switch to disconnect the entire bank without the need to pull out a wrench.

I would also add a circuit breaker between the solar panels and the solar charger. This allows an easy way to cut the panels which should be done anytime you are disconnecting the battery from the the SCC.

I don't see a shunt based battery monitor. Highly recommended!

Here is the schematic for my system which may help you understand my thought process building a somewhat similar system.

 

[rafrojack]

Thanks!

So let's see if I'm getting this right.

I should add a switch in between the PV & SCC & another switch in between the battery bank itself & the rest of the system. Actual cutoff switches because CBs are not necessarily meant to be used as a switch right?

A shunt based management system is basically a management system that is wired into the circuit with a resistor that can read the voltage/amps passing through correct? Yours is connected on the neg end of your battery hook up so I'll follow suit.

No temperature sensor for the batteries? Alright!

I see you have a 120v/12v power dist board, PDB, which would help cutdown on items needed I'm guessing, since in my system I have a 12v fuse box & a seperate 120v box. Or is there a particular reason you did one PDB?

Looks pretty good.

Lithium batteries typically don't use a temp compensation for any chargers. Battleborn specifically clarifies no temp compensating which could cause the BMS to shut down charging. Unlike traditional batteries lithium accepts a good charge under a wide variety of temperatures.

https://battlebornbatteries.com/wp-content/uploads/2017/09/Battle-Born-Manual.pdf

Personal preference but I prefer to have a master battery switch to disconnect the entire bank without the need to pull out a wrench.

I would also add a circuit breaker between the solar panels and the solar charger. This allows an easy way to cut the panels which should be done anytime you are disconnecting the battery from the the SCC.

I don't see a shunt based battery monitor. Highly recommended!

Here is the schematic for my system which may help you understand my thought process building a somewhat similar system.


View attachment 286

t's

 

[TCgreg]

I like having the battery disconnect. Choose one that is rated for the maximum amperage it could see. You could use a circuit breaker. I have terminal fuses on the two 300amp batteries (as well as the battery protect) so that circuit is already fused. The switch is heavy duty and will take infinite number of uses without breaking down.

The shunt is a monitoring system not a management system. It simply measures amperage passing both ways through it. The advantage is an accurate measure of the batteries remaining capacity. It attaches to the negative side of the battery before any and all loads. I chose the Victron but there are other units on the market that are less expensive. I think Will did a video on a less expensive alternative. The Victron is nice in that it has bluetooth so you can monitor what's going on with your phone.

The 12v/120v distribution panel is what the camper came with. If you are building a system for a van conversion from scratch you are on the right track with your AC breakers and DC fuse block.

 

[Supervstech]

You state 12v panels wired parallel, but you show them wired in series... connected to the mppt it won’t matter, I just want to point this out.

 

[guyman]

Looks pretty good.

Lithium batteries typically don't use a temp compensation for any chargers. Battleborn specifically clarifies no temp compensating which could cause the BMS to shut down charging. Unlike traditional batteries lithium accepts a good charge under a wide variety of temperatures.

https://battlebornbatteries.com/wp-content/uploads/2017/09/Battle-Born-Manual.pdf

Personal preference but I prefer to have a master battery switch to disconnect the entire bank without the need to pull out a wrench.

I would also add a circuit breaker between the solar panels and the solar charger. This allows an easy way to cut the panels which should be done anytime you are disconnecting the battery from the the SCC.

I don't see a shunt based battery monitor. Highly recommended!

Here is the schematic for my system which may help you understand my thought process building a somewhat similar system.


View attachment 286

I know I'm off topic, what programme do you use for drawing

 

[rafrojack]

I know I'm off topic, what programme do you use for drawing

I used powerpoint like an amateur. I'd like something better honestly.

 

[rafrojack]

You state 12v panels wired parallel, but you show them wired in series... connected to the mppt it won’t matter, I just want to point this out.

I've been so deep into this wiring hole that now I'm confusing myself. I have four 12v, 5.29a, 100w panels for a 300ah (3) battery bank & a 40 amp MPPT (to allow for growth of the system in the future). I'm assuming I'd want to wire the panels in parallel so that my voltage stays at 12v, amps increase to 21.16a & watts at 400w...which is what I want for efficient charging right? If I do series-parallel my panels will then produce 24v, 10.58a, & 400w which is not ideal. If in series I'll produce 48v, 5.29a, & 400w. Can someone please check me on this. I've drank too much of the kool-aid.

 

[TCgreg]

With your MPPT solar charger you can run your panels in parallel, series, or a combination. The MPPT charger will then make the high voltage input into 12v output current compatible with your 12v battery bank.

In general series will give you better efficiency of wiring and some possible better charging in low light where panels in parallel may not reach minimal voltage by themselves. Typically these low light solutions are producing next to no amps anyway so sort of a moot argument IMO.

The advantage to parallel is better performance if one or more panels have shading. This point is disputed, but that's what I found through my testing. A series/parallel such as 2 in series then 2 groups in parallel may be a great option. I recommend people test this series vs parallel options themselves and factor in how much shading they might expect where they like to park.

If you do go in series, or series parallel you have the option to make up a 24v battery bank. That will be slightly more efficient for the solar to battery charging equation but does present a couple challenges. You will need a 24v inverter if making 120v power is a goal. You will also need a 24-12v step down converter to run any 12v devices in your system.

 

[TroyW]

I used powerpoint like an amateur. I'd like something better honestly.

I like Google Drawings. It's easy and free.