Electrical project in the planning need pointers

[wincrasher]

On my latest big trip, I really could have used an inverter. On many of my stops, I ended up firing up the genny for a few minutes to either use the microwave or my toaster.

So I've been thinking about a big electrical upgrade project that isn't too crazy expensive or radically alter the van. So no alternator upgrade at this time - I'm fine with using the Onan for the time being.

So here's what I'm considering to install:

Inverter:
SWXFR-1230 - Kisae Technology

Charger:
AC-1260 - Kisae Technology

Monitoring:
https://www.victronenergy.com/battery-monitors/bmv-700

If you are familiar with the Travato 59K, then you'll understand there are space constraints to installing this equipment. Basically, you have two underbed equipment areas on each side of the van. Unfortunately, all the electrical components are not together. On the passenger side, you have the existing converter/charger and the 12v and 120v panels. On the driver's side, the transfer switch. The drivers side has space big enough for the inverter (and it has a ventilation grill into the cabin), the passenger side has space enough for the charger.

The monitor installation looks straight forward enough. The only challenge is finding a pathway (or drilling a hole) to pass control wiring down under the van where my lithium batteries are located.

The existing converter charger uses 6 AWG wiring, so I think that may be OK to reuse. The existing unit it rated 45 amps, but real world it runs anywhere from 35-40 based on my crude observations. My big question here is do I need something to substitute the converter function of this unit? I do like the Kisae charger because it's compact, has a lithium profile and has a remote display unit. I plan on installing a shut-off switch so I can completely turn this off when running on inverter. It does have it's own internal programmed shutoff when full charge is achieved (termination amperage).

The inverter unit I'm looking at certainly meets my space limitations. It also has a remote display and automatic switching built in. So when it's off, it will still pass thru the 30A shore service or the generator power. The Xantrax and Magnum units are so large, they would most likely have to be placed in one of my storage areas, which I don't really want to give up, as storage is pretty limited already. The big challenges here are routing the cabling to batteries (I figure 4/0 will be needed, fuse & disconnect switches), drilling big holes!, and how to tie into the house 120v system. I'm uncertain here if I should put this downstream of the existing transfer switch, or run cabling to the existing 120v panel. My van has an EMS system that does load shedding if the 120v amps get too high. I need to preserve this functionality, and assume it will still work on inverter power.

My intention, since the inverter is so large, is to have the ability to run everything in the coach on the inverter. Granted, I don't have that much battery capacity, but I want the capability, even if it would be for a short time. Ideally, I'd be able to run the microwave and a toaster at the same time for short periods. Other desires would be to run the Truma water heater or furnace on electric mode if I were to run out of LP.

Any input is welcome! I am hoping to DIY this, but if it seems too daunting, then I have a dealer that can do the work with parts I supply.

[booster]

Should be an interesting project! Space is always the killer, I know that issue all too well.

A couple of observations.

The charger is one of the newer style that many manufacturers are going to that terminate the absorption stage (or fixed stage in two stage profile) by measuring current. While in many ways better than timers only, the units that measure the current internally do have some things to take into account. The manual shows that charger using 10% of the charger max capacity as the amps for cutoff, so 6 amps for the 60 amp charger. This is likely going to be pretty high for your smallish lithium battery bank, so the batteries will not get totally full and cost you a bit of capacity. It will not hurt the batteries though, like it would with AGMs. The other side of this same issue is that any loads that are running in the van will be seen by the charger's amp measuring and be counted as charging current. These loads can keep the charger from getting to the cutoff amps as soon as it would without them on. If you get lucky, the too high cutoff setting will be balanced with your loads to some degree. You probably don't have 6 amps of load most of the time, so it shouldn't lock in and never end charging. Your frig is on/off however and the being below 6 amps only has to be for a short time, so it won't count much in the calculating. The guess is that charging will stop quite a bit early. This is the same thing we had with the Blue Sea charger (although the transition amps were settable), so we know it well.

The manual didn't show a profile for the lithium setting, but it appears it does a full shutoff, and then presumably a recharge when the batteries get to a set voltage. This is pretty common for lithium battery profiles, and desirable because it protects the batteries from long term float, which many are saying is not good for them. What it doesn't do is give you coach power from the charger to power stuff, once the batteries are charged. Everything will run off the batteries until they discharge enough to restart the charger. Depending on the timing of things, you could unplug from shore power with the batteries less than full. Not a big deal if you have a huge bank like davydd, but could be important in a smaller bank. You could run a separate converter (power supply) to run the coach, but then you would also need a switching system to go between it and the batteries depending on if shore power was on. Of course you would also need to find a place for it. Is there not enough space for the a larger PD charger?

3000 watts is a big inverter and will be capable of using a lot of amps, especially in startup surges. You may want to check with the battery manufacturer to make sure that the internal wiring in the batteries and BMS can handle very high amps. The was mention by someone recently that said they had seen a current limit requirement on the packaged lithium battery units (might have been in relation to Pleasure-way's setup). It will also require good air access for cooling, as it will move a lot air through it if running hard.

[booster]

On the 110v wiring I think it should be pretty simple, and not need a shutfoff for the charger.

Shore power and gen to transfer switch.

Output from transfer switch to the input of the inverter and to the input of the charger.

The inverter will switch back and forth from battery power or shore/gen, and the charger will only be powered by shore/gen and be isolated from the battery powered 110v from the inverter.

[wincrasher]

Thanks for the input.

Looking thru the charger manual, it looks to me the setting for termination can be either 3A, 6A or 12A. 3A would be what I'd want to do. What I didn't see from looking in that manual was at what point does it come back on.

The batteries are limited to 50A input and 100A output. So for the two, that's 200A output. That would be more than I'd hope to ever see! The inverter spec sheet says it will do 6000watts peak, but doesn't say for how long - I can only assume milliseconds. There was one brand I looked at that claimed it would do so for 20 secs!

[wincrasher]

Originally Posted by booster

You could run a separate converter (power supply) to run the coach, but then you would also need a switching system to go between it and the batteries depending on if shore power was on. Of course you would also need to find a place for it. Is there not enough space for the a larger PD charger?

I thought that one nice feature of this charger was you can put it into power supply mode. So if I was really low, I could switch it over on the display panel and feed the 12v system and it would also charge at the same time using a CV profile. I think that's what it's saying.

[mojoman]

I have the 1240 charger, I had to move mine to a well ventilated area as it would trip off from heat when operating at max after a period of time. Incorporate some cooling fans where ever you install them if confined or poor ventilation. It will make you equipment last longer too.

[booster]

Originally Posted by wincrasher

Thanks for the input.

Looking thru the charger manual, it looks to me the setting for termination can be either 3A, 6A or 12A. 3A would be what I'd want to do. What I didn't see from looking in that manual was at what point does it come back on.

The batteries are limited to 50A input and 100A output. So for the two, that's 200A output. That would be more than I'd hope to ever see! The inverter spec sheet says it will do 6000watts peak, but doesn't say for how long - I can only assume milliseconds. There was one brand I looked at that claimed it would do so for 20 secs!

It is interesting how the manual is written. On page 6 it shows a charge profile with the transition to float stated as 10% of Imax, which is typically how this is listed by manufacturers. But later on in the text the do plainly say that you can set the preset levels of current. That same profile shows a recharge start at 12.5v, but they have the current showing wrong at that stage. If the lithium program does the same recharge point (my quick look through didn't find that spec or any settings for it), that is pretty low for lithiums as they will be very discharged. You likely would be able to get another charge cycle by removing and reconnecting shore power manually, or there may be some kind of force function to do it from the remote.

It all depends on models you have, but both the toaster and micro will probably be in the 100 amp range +/-. With full batteries or on the engine running, our micro will be at 90+ and with 50% full batteries it will be closer to 110 amps. Both the toaster and micro will have considerably higher than that starting currents, so you are probably going to be marginal running both at the same time. The big questions come in relation to the 100 amp battery limit. Is it a hard limit, or is it a heat related limit that would allow for some surge in starting? What type it is will probably dictate what amp rating you would use for a fuse to the inverter to protect the batteries. It is pretty unusual to need a fuse to protect the batteries, as it much more often that the wiring or the inverter itself is the most vulnerable, and for those there are lots of charts for fusing that allow for surges and such.

[wincrasher]

The manual indicates a 350A needed for the inverter where they talk about wiring. Not sure on the basis of the limit on the batteries - all they say is max output.

[booster]

If I understand correctly, you want the charger tap upstream of the transfer switch? If so, that would work, but you wouldn't be able to run the battery charger off the generator.

It is all pretty sequential in layout. First the 110v power.

First the transfer switch decides if it has generator or shore power, and passes whichever it has through.

Then the passed through source goes to the battery charger to charge the batteries through the charger. The passed through power also goes to the inverter, which then gets to make another choice.

If it sees the generator or shore power, it will pass it through to the van's 110v circuits.

You then have 110v to all your stuff and are charging the batteries.

Now if there is no 110v source (no generator or shore power)

In this case, all that happens is the the inverter (if it is on) switches to inverting, with the internal switch disconnected from the transfer switch and charger (and thus the shore power and generator wiring). It internally connects it's inverted output to run the van.

It should all be very seamless and automatic, if things work the way I think they will.

If you connect anything ahead of the transfer switch, you will lose some of the functions. You might even want to consider moving your surge suppressor to the output of the transfer switch so both the shore and generator power can benefit from it.

[wincrasher]

OK, I follow. Most likely I'll go with the first scheme - wiring from the transfer switch to the input of the inverter.

Should there be a breaker between these two?

Also, where specifically should I run the power cable to the charger? To the AC input on the inverter along with the cable from the transfer switch? Should it not have it's own breaker?

The AC outputs on the inverter are all inverted - there are no dedicated pass-thru outputs.

[booster]

Originally Posted by wincrasher

OK, I follow. Most likely I'll go with the first scheme - wiring from the transfer switch to the input of the inverter.

Should there be a breaker between these two?

Also, where specifically should I run the power cable to the charger? To the AC input on the inverter along with the cable from the transfer switch? Should it not have it's own breaker?

The AC outputs on the inverter are all inverted - there are no dedicated pass-thru outputs.

Where you need breakers can be pretty weird and you will get a lot of different opinions, these are just mine.

The inverter has a 30 amp pass through, which is the same as you shore power inlet capacity, so as long as you use wiring capable of carrying the 30 amps from the transfer switch to the inverter, you should be good to go. The breaker on shore power source will protect to the 30 amp level, and the breaker in the generator will protect it when on generator. We will probably get some that will say that isn't enough, but that is there right.

Whether or not you need a breaker to the charger would depend on what the charger instructions say, and it appears that they are calling out 14ga wire which would indicate a 15 amp breaker. They also say 1050 watts, so that would reinforce that.

I think I would take a 10ga 110v cable from the transfer switch to a small breaker box. Connect straight through the box to the inverter, and use a 15 amp breaker in the box and run the output from that to the charger.

The specs and the manual both say it has a 30 amp transfer switch. Both the pass through and the inverted 110v come out of the inverter, but only one of them is actually inverter output, the pass through is just that, a closed relay to shore power.

[wincrasher]

Originally Posted by mojoman

I have the 1240 charger, I had to move mine to a well ventilated area as it would trip off from heat when operating at max after a period of time. Incorporate some cooling fans where ever you install them if confined or poor ventilation. It will make you equipment last longer too.

Were you running yours in "silent mode" with it cycling off the cooling fans?

Also, does yours have an on-off switch on the control panel? I was trying to figure out if it can be manually turned off, or if you have to switch off the breaker or unplug it.

[mojoman]

It tripped off a couple of times as I was testing it running it at maximum capacity inside a cabinet. I believe the fan was running. I moved to a open area and it didn't trip. Have the remote panel and installed a switched 120v outlet dedicated to the charger. The remote panel is exact same as the panel on the unit so it has the same functions, don't know if there is an off and on. I installed it as a shore power/generator back up charger incase the inverter charger craps out.

[wincrasher]

Well, I have all my parts ordered and got many of them delivered today. Waiting on my cable to arrive so I can get started.

I think I will also do a battery winterization project while I have everything torn apart.
I found heating pads that are used for heating motorcycle handle grips. https://www.amazon.com/gp/product/B0...?ie=UTF8&psc=1 They have two settings - high & low, with the high using 3 amps. With one kit on each battery, that would be 6 amps max.

My thoughts are to use a foil covered insulating board to cover these batteries. The heat pads under the board. I also got digital temp probes to install on each battery - I'll install those inside each battery casing.

In the coach I'll have a master control switch to select hi and lo heat, with two lcd readouts on battery temperature. All will be manual control, no thermo switch or anything complicated. I'm going to power all this off the 12v breaker box, not from the batteries themselves.

[Davydd]

With that heat on the battery are you planning on joining Mike Wendland's Winter Freezeout this coming January?

[wincrasher]

I hope it's not too hot against the plastic battery housing. Maybe I should put a metal plate in there to dissipate it a bit.

[wincrasher]

Sadly, I can't get to my project this weekend - issues at the jobsite keeping me from it.

One thing I've noticed in videos on prepping my cables, most all of them show crimping on the lugs plus adding solder.

I asked a contractor about these large cables and he indicated they never solder the larger ones - the crimp is good enough. Granted, to them 4/0 is small cable.

What does the group say?

[mojoman]

I used a hydraulic crimper from Amazon,good enough, follow with some marine heat shrink, the stuff with the sealant inside.

[booster]

Originally Posted by mojoman

I used a hydraulic crimper from Amazon,good enough, follow with some marine heat shrink, the stuff with the sealant inside.

I use a Molex hammer crimper with a 3 pound hammer on a solid steel surface. All very tight, all check zero resistance. As mentioned, be sure to use the good shrink tubing.

[mojoman]

Might suggest a shore breaker that has a safety feature to prevent wrong polarity. Two of my blue sea devices have them and show a green light when the power is good. Otherwise a simple $10 plug in voltage tester will work before plugging in to a RV site panel.