Can anyone critique my setup? Electrical diagram v2 for '93 HiAce

[dads_old_hypercube]

electrical v2
bonus van layout (thought about B2B but later decided against it)

Vehicle is a 1993 Toyota HiAce imported from Japan, so the battery and engine are on the left side, driver on right.

Components:
Charge Source:

• 2x Renogy Eclipse 100W Solar Panels wired in parallel
• EPEVER 30A MPPT
• 45A fuse
• Positive Busbar
• Switch

Battery:

• 100A fuse
• 100Ah Lithium Battleborn
• Shunt + AiLi Battery Monitor
• Fusebox + negative busbar combo

Loads:

• 1-2 LED's (thinking mostly AA battery powered lights)
• Water Pump
• Vent Fan
• 12V Cigarette Lighter (to power laptop charger)
• 12V USB Charger or another cigarette lighter for mac charger with USB outputs

Load Calculations:
Minimum Loads:

• Work Laptop Charger: 90W/12V = 7.5A
• Work Phone Charger (12V USB): 6W/12V = .5A
• Fan: 36W maximum/12V = 3A
• Total Minimum Load: 132W/12V = 11A

Maximum Loads (worst-case):

• Work Laptop Charger: 90W/12V = 7.5A
• Work Phone Charger: 6W/12V = .5A
• Verizon Jetpack: 6W/12V = .5A
• Fan: 36W maximum/12V = 3A
• Mac Laptop Charger: 90W/12V = 7.5A
• Personal iPhone Charger (from same Mac charger): 20W/5V = 4A
• LED Lights: Might go with battery-powered lights but just to budget for some I'd say, 60W/12V = 5A
• Water Pump: Unsure, haven't checked the existing pump, but let's say 35W/12V = 3A
• Total Maximum Load: 343W/12V = 28.5A

Daily Minimum Load:

• Work Laptop for 2 hours: 180Wh
• Work Phone for 2 hours: 12Wh
• Fan on low for 8 hours: 144Wh
• Total Daily Minimum Load: 336Wh/28Ah

Daily Maximum Load:

• Total Daily Max Load: 1000Wh/83Ah

Based on a battery life of 1,200Wh/100Ah, I'd run it at about 30% capacity each day at minimum, and 80% capacity on a worst-case scenario day. Running only minimum loads then, I could get by for about 3 days without recharging at all.

Questions:

• Is this a fair assessment? Would anyone add/modify/remove anything in that?
• Is 200W enough to recharge the battery after a day of average use (assuming "average" to mean somewhere in the middle of min/max loads)?
• Are my fuse and wire gauge specs accurate (no wire should be over a few feet, with exception of the fan wire and solar cables)?
• Is there any way to charge safely from a 60A-rated alternator? I'd considered B2B but the lowest B2B I can find is 20A, which seems high for my alternator.
• Is there any way to charge the battery itself from shore power, or is shore only capable of charging inverter appliances?
• Is the switch placement (after MPPT positive wire) correct if my intention is to use it as a solar shut-off switch in case I want to make modifications to the battery or load components?

Thanks very much!

 

[bjfields]

Can we see a pic of the HiAce?

 

[bjfields]

[*]Is there any way to charge the battery itself from shore power, or is shore only capable of charging inverter appliances?
[*]Is the switch placement (after MPPT positive wire) correct if my intention is to use it as a solar shut-off switch in case I want to make modifications to the battery or load components?

Install an Inverter/charger from the vendor of your choice and an RV power inlet to charge from shore power.

I have cutoff switches on both the battery positive and the PV positive for exactly the reason you indicate.

 

[Dzl]

First off, take my comment with a grain for salt, as I am not the most experienced or knowledgeable when it comes to solar or lithium and still consider myself a beginner. But I figured I would try to pass on some of the information I have gathered and learned along the way.

Questions:

• Would anyone add/modify/remove anything in that?

I'm wondering if you've thought through the Renogy Eclipse panels. I know they are the highest efficiency but it looks like they are close to double the price of the regular renogy monocrystalline panels and 22% efficiency versus 21% for the regular mono panels. Unless those panels are necessary to fit the space available on your roof, or unless there are other features that justify the cost, I'm not sure if I would spend the extra money for the marginal efficiency gain. I'm not advising you against it, just thinking out loud, and curious what your reasoning is.

• Is 200W enough to recharge the battery after a day of average use (assuming "average" to mean somewhere in the middle of min/max loads)?

Generally I've heard people use 4-5 hours of charging at 70% of rated wattage as a general rule of thumb if you flat mount your panels and use an MPPT charge controller. So (200 x 0.7) x 4.5 = 630 W/hrs on an average day. But there isn't really an "average day" so it will vary depending on where you are in the world and what season it is. There are calculators that help estimate this based on region and some that even account for equipment efficiency, but I don't know any off the top of my head to recommend.

• Is there any way to charge safely from a 60A-rated alternator? I'd considered B2B but the lowest B2B I can find is 20A, which seems high for my alternator.

This is a good question, I would contact Sterling Power or Victron directly about this (If it were me I would contact Sterling, they seem to know there stuff when it comes to safely charging with alternators). The smallest DC-DC / battery-battery smart charger I've seen is a Victron 18A 12V charger. I'm not knowledgeable enough to know whether 18-20 or even 30 amps would be too much for a 60 amp alternator.

• Is there any way to charge the battery itself from shore power, or is shore only capable of charging inverter appliances?

Yes definitely. There are chargers and charger/inverters that take care of that. Two high quality options would be the Samlex Evo and Victron Multiplus are both higher quality, higher end inverter/chargers with good feature sets and good reputations. There are also many chargers built for the RV industry that are probably cheaper. Here are some chargers reccomended on Will's website.


And as to your Hiace:

I love those little things. I almost bought a Hiace Truck a while back. It was a flatbed, biodiesel, 4x4, 5 speed manual, right hand drive. I still kick myself for not pulling the trigger on it. I hope you get many good miles and have man fun adventures in your Hiace!

 

[Maast]

Any refrigeration? Thats the biggest load on my boat even though I only have one of those small cooler-type compression cycle refers like this one. In a 70 degree cabin it runs for 5-10 mins then shuts off for another half hour or so. I've got mine rigged on a drawer slide to come out from under the galley w/ a rubber bungie to hold it in place when under way.
Next biggest power user is the diesel fired hot-air heater (love that thing). It doesnt use a lot of power, but when its on its on constantly.

 

[tictag]

Hey, dads_old_hypercube, love the electrical diagram! Here's my tuppence worth:

Is this a fair assessment? Would anyone add/modify/remove anything in that?

If your MPPT can support the higher system voltage, wiring your panels in series would reduce resistive losses in the PV cables i.e. higher voltage = lower current.

I would consider adding a battery protection module to ensure no matter what happens your battery will never be excessively drained, yes, your battery's BMS will likely have such a feature but the battery protection module can double as an isolation switch, offering safety and convenience.

Your battery monitor is low-side sensing so also requires a power supply. You've not shown this on your diagram. Be sure to fuse this supply.

Is 200W enough to recharge the battery after a day of average use (assuming "average" to mean somewhere in the middle of min/max loads)?

Using your example, you need to replenish 55AH (660WH at 12V) per day. A 200W array would only generate this in lab conditions, assume 80% efficiency in summer, 20% efficiency in winter over 5 hours good sun on average per day. In summer you'd replenish 800WH (200W x 80% x 5 hours = 800WH), in winter 200WH (200W x 20% x 5 hours = 200WH). When considering other system inefficiencies e.g. power loss in cables, MPPT, charge/discharge etc, I would say your PV system is under-specified for your needs.

Are my fuse and wire gauge specs accurate (no wire should be over a few feet, with exception of the fan wire and solar cables)?

As a rule of thumb, your cable should support the maximum anticipated current and your cable run should not drop more than 3% of the supplied voltage. Copper has a very well known current capacity and resistance per meter and there are loads of tables out there on t'interweb for various cross sectional areas. For example, 8AWG copper wire would support up to around 75A and at 28.5A a 1 meter run would drop 0.06V (V=IR, I=28.5A, R=0.002 x 1m = 0.06V) or 0.5% meaning that your cable is way over-specified. Some would say well it's better to be over-specified than under-specified but all you're doing is adding unnecessary weight and cost to your project.

Not convinced on the need to fuse your PV cables. Fuses are only there to protect the cable connecting devices from excessive current. On a battery lead, yes, absolutely, a battery could generate hundreds of amps in a short-circuit scenario but a PV panel would only ever supply its I(SC) current, maybe 12A on a bright sunny day? Your PV cable should easily be able to accommodate this.

Make sure you use solar PV specified cable up to the panels. This cable is usually black and has two layers of insulation, the top most being UV resistant.

I am assuming each 12V circuit is fused in your 'fusebox'.

Is there any way to charge safely from a 60A-rated alternator? I'd considered B2B but the lowest B2B I can find is 20A, which seems high for my alternator.

A DC-DC Converter is the best option. Remember that the charge current is NOT what the DC-DC converter can supply, for example if your battery is already fully charged it will only consume maybe 0.5A at most, your charger will determine the charge current and most either have a maximum charge capacity or the charge current can be programmed.

Is there any way to charge the battery itself from shore power, or is shore only capable of charging inverter appliances?

Yes, many options for this from a simple mains battery charger to a more comprehensive inverter/charger solution e.g. MultiPlus. You'll need to research galvanic isolation in order to safely use shore power.

Is the switch placement (after MPPT positive wire) correct if my intention is to use it as a solar shut-off switch in case I want to make modifications to the battery or load components?

Yes. It is considered best practice to first cover the solar panels before isolating them in order to avoid voltage surges. As already mentioned, it is a good idea to also include a battery cut-off.

I hope that helps!

David.

 

[tictag]

One more point about using your alternator:

Is there any way to charge safely from a 60A-rated alternator? I'd considered B2B but the lowest B2B I can find is 20A, which seems high for my alternator.

The biggest challenge for older alternators is that they are generally cooled internally i.e. the fan runs at the engine's RPM and, therefore, idling can cause heat build up if drawing too much current. All alternators are different so I would leave the engine idling then start off with a low charging current, slowly build up until the alternator is just too hot to touch - that should be you maximum safe current draw. If that's only 5A then, I'm afraid, it's 5A. You could test this first with a load bank e.g. power resisters or incandescent bulbs etc if you are not able to program the charge current.

One thing you should NEVER do is connect your alternator directly to your LFP battery, even via a switch-charge-relay system. The low internal resistance of LFP batteries will attempt to draw waaaay too much current from your alternator putting it at risk of burnout.

Edit: Corrected typo