Lithium + Victron + Solar Install and questions

[howson]

bellis

Very well done video--suggest you give it a look:

[bellis]

bellis

Very well done video--suggest you give it a look:

Thanks - have watched that a couple of times. Are you suggesting I rely on the software limited to limit the multiplus to 30amps (setting may say 25A?) instead of putting in a CB after the EMS? Observations: He really focuses on a transfer switch or smart transfer switch and mostly on 50amp. I don't see a need for that in my build. He also wires his batteries up right, but less than ideal (parallel, but not to a bus bar).

howson gbkims - I was going to use the existing DC wiring (reverse it) when I removed the existing converter. IE from the multiplus to the Fuse distribution panel. I figure it goes from the DC side of the distribution panel to the current battery disconnect switch. Is this a mistake?

In his video he has a 2nd fuse after the first battery disconnect switch (50 amp diagram) and then another switch, and then his DC load on the breaker/distribution panel. Is that 2nd fuse really necessary? I see how a 2nd switch to cutoff the load could be nice.

Random FYI - Progressive tells me that a Circuit breaker after the EMS is not necessary. I have asked them for more details....hopefully they can explain it better for me. I guess it never hurts to put in even if not needed....It would give the ability to shut off shore power without unplugging.

[howson]

Are you suggesting I rely on the software limited to limit the multiplus to 30amps (setting may say 25A?) instead of putting in a CB after the EMS? Observations: He really focuses on a transfer switch or smart transfer switch and mostly on 50amp. I don't see a need for that in my build. He also wires his batteries up right, but less than ideal (parallel, but not to a bus bar).

I'm not sure what you're asking. The 3000/12 Multiplus is capable of generating 25A of 120vAC for an extended period of time--that's what it's made to do. (3000W/120V=25A) Your camper is wired to provide up to 30A from shore power. If you somehow duplicated trying to pull 30A from the Multiplus, it will only last a relatively short time until it goes into "overload". Anything above 30A will open the trailer's primary circuit breaker, assuming the load is after the power distribution panel. Below is a chart from Victron:

I was going to use the existing DC wiring (reverse it) when I removed the existing converter. IE from the multiplus to the Fuse distribution panel. I figure it goes from the DC side of the distribution panel to the current battery disconnect switch. Is this a mistake?

For the original camper DC circuits I used the original OEM wiring.

In his video he has a 2nd fuse after the first battery disconnect switch (50 amp diagram) and then another switch, and then his DC load on the breaker/distribution panel. Is that 2nd fuse really necessary? I see how a 2nd switch to cutoff the load could be nice.

The only thing I can think of with the second fuse is to protect the long run from the nose of the camper to his distribution panel. Perhaps he doesn't have the 30A self-resetting circuit breakers the GD units have in the nose? I don't know. The second fuse, IMO, is redundant if you retain the OEM circuit breakers.

[bellis]

Random FYI - Progressive tells me that a Circuit breaker after the EMS is not necessary. I have asked them for more details....hopefully they can explain it better for me. I guess it never hurts to put in even if not needed....It would give the ability to shut off shore power without unplugging.

Progressive says this is because the 30 amp breaker at the pedestal will provide protection to the wire. I am thinking about eliminating this CB after the EMS. Not trusting the pedestal power is one thing, but not trusting the CB? I could put it in...but that is probably duplicating effort and taking up space unnecessarily. Happy to hear thoughts though.

[bellis]

Most of my gear is in. Still waiting on 1 battery switch (which will be a load on off switch). I got (2 runs of 8 AWG and a couple pull strings pulled from the entertainment center to the pass through yesterday (I have done a number of cable pulls in life; this one was not the worst, but not the easiest either). I have a coat of poly dried on a backer board (for pass through) and currently waiting for stain to dry on battery shelving.

Anyway, here is the latest drawing. Not sure if I will switch to another product and draw AC/DC separately or not (time).


howson / gbkims / Guest / TucsonJim / Running from Gnats

Drawing Changes:
1. I put the solar + before the main battery disconnect switch. My thought is that if solar panels are connected, let them charge the battery? Is this a mistake? I have a CB on that line so I can turn solar only off.
2. Updated 150A CB to pic of suggested purchase.
3. Bought 2 more bus bars and put them in the drawing (shrank them on image to fit).
4. Moved 2nd Battery switch to only in front of Fusebox. Have cerbo and multiplus behind it. Multiplus can be turned off or charge only and I may want the Cerbo on if I connect a GPS module? (even if it drains the battery).
5. I stuck with the same brand battery disconnect switch, but had to upgrade it to a beefier model. Updated links on 2nd page.
6. Considering removing 30A Circuit Breaker to protect the wire between the EMS and the multiplus. Progressive says it is redundant and the pedestal CB should protect the wiring. Not sure I see a need to have an on/off after the EMS.

Notes: I still have an un-purchased battery disconnect on the solar wiring side...but solar wiring is not complete. Trying to figure out if I am going to run parallel / series or both (which will change wire size required).

Thanks for all the input so far...check out the latest drawing.

[gbkims]

Most of my gear is in. Still waiting on 1 battery switch (which will be a load on off switch). I got (2 runs of 8 AWG and a couple pull strings pulled from the entertainment center to the pass through yesterday (I have done a number of cable pulls in life; this one was not the worst, but not the easiest either). I have a coat of poly dried on a backer board (for pass through) and currently waiting for stain to dry on battery shelving.

Anyway, here is the latest drawing. Not sure if I will switch to another product and draw AC/DC separately or not (time).


howson / gbkims / Guest / TucsonJim / Running from Gnats

Drawing Changes:
1. I put the solar + before the main battery disconnect switch. My thought is that if solar panels are connected, let them charge the battery? Is this a mistake? I have a CB on that line so I can turn solar only off.
2. Updated 150A CB to pic of suggested purchase.
3. Bought 2 more bus bars and put them in the drawing (shrank them on image to fit).
4. Moved 2nd Battery switch to only in front of Fusebox. Have cerbo and multiplus behind it. Multiplus can be turned off or charge only and I may want the Cerbo on if I connect a GPS module? (even if it drains the battery).
5. I stuck with the same brand battery disconnect switch, but had to upgrade it to a beefier model. Updated links on 2nd page.
6. Considering removing 30A Circuit Breaker to protect the wire between the EMS and the multiplus. Progressive says it is redundant and the pedestal CB should protect the wiring. Not sure I see a need to have an on/off after the EMS.

Notes: I still have an un-purchased battery disconnect on the solar wiring side...but solar wiring is not complete. Trying to figure out if I am going to run parallel / series or both (which will change wire size required).

Thanks for all the input so far...check out the latest drawing.

I'd skip the 30A CB since it does get the protection from the RV pedestal, and skip the On/Off switch after EMS since this is an RV with power cord you can disconnect easily.

What drawing program are you using?
I just started using SmartDraw and like it so far. It can do some things easier than 2D CAD software.

[howson]

1. I put the solar + before the main battery disconnect switch. My thought is that if solar panels are connected, let them charge the battery? Is this a mistake? I have a CB on that line so I can turn solar only off.

"Mistake" implies something will go "sizzle" if you leave it this way. So it's not a mistake. It's a choice and your system will work accordingly. In my system, that first cutoff switch is meant to electrically isolate the batteries from everything, so the solar + is on the other side of the switch than what you've chosen. Neither is "right" or "wrong" IMO.

Remember you'll have two different scenarios with "OEM" DC wiring. One wire will be after the OEM shutoff (the majority of the DC circuits in the camper) and the other OEM DC circuit is not affected by the OEM shutoff (emergency brakes, front power jack, propane detector, etc.) Unless I missed it I don't see where you are connecting the items not controlled by the OEM's shutoff.

If you look closely at my schematic, the connection for the items I am referencing is the input of the second cutoff switch (so the items are only turned off if I disconnect at shutoff 1). If I turn off shutoff 1 it will be a very deliberate act that I know will disconnect everything in the camper. I would not tow in that condition--ever.

[bellis]

"Mistake" implies something will go "sizzle" if you leave it this way. So it's not a mistake. It's a choice and your system will work accordingly. In my system, that first cutoff switch is meant to electrically isolate the batteries from everything, so the solar + is on the other side of the switch than what you've chosen. Neither is "right" or "wrong" IMO.

Remember you'll have two different scenarios with "OEM" DC wiring. One wire will be after the OEM shutoff (the majority of the DC circuits in the camper) and the other OEM DC circuit is not affected by the OEM shutoff (emergency brakes, front power jack, propane detector, etc.) Unless I missed it I don't see where you are connecting the items not controlled by the OEM's shutoff.

If you look closely at my schematic, the connection for the items I am referencing is the input of the second cutoff switch (so the items are only turned off if I disconnect at shutoff 1). If I turn off shutoff 1 it will be a very deliberate act that I know will disconnect everything in the camper. I would not tow in that condition--ever.

Thanks Howson that and the drawing are incredibly helpful. I have not drawn this part of the DC side on my trailer in part, because I am not sure how it comes together. I am aware of all the parts...just not aware of where it comes together. I have looked under the frame and I see it...but am not 100% confident where each wire leads etc.

So, the above with the solar change is not a mistake....but would you recommend one way or the other? Like you said, it really is a choice...just trying to weigh the pros/cons.

[howson]

Like you said, it really is a choice...just trying to weigh the pros/cons.

All I can tell you is I have no regrets or desire to rewire my circuit after many months of usage. I like the ability to completely disconnect everything "downstream" from the batteries with one switch if needed. (It is important--very important--to remember that the solar panels MUST be disconnected from the MPPT first THEN the battery power from the MPPT. Re-powering is the reverse. Battery power to the MPPT THEN panel power. Did I mention this is very important???)

I know exactly where you're at--I laid awake at night thinking about the DC wiring, knowing I didn't have a complete grasp of how it all fit together. I spent a lot of time crawling under the camper and tracing wires until I knew exactly what-went-where-and-why.

[Guest]

bellis ,

Keep in mind if the solar system is directly connected to the batteries you will be exercising them if there is any draw on the system. I do not have roof top solar panels but I would prefer to completely isolate the battery(s) and store it at 50% SOC for longer life. Lithium batteries age faster if kept at their extremes. This would be discharged as well as fully charged.
Every persons needs are different so this approach may not be for everyone.

Jim

[bellis]

bellis ,

Keep in mind if the solar system is directly connected to the batteries you will be exercising them if there is any draw on the system. I do not have roof top solar panels but I would prefer to completely isolate the battery(s) and store it at 50% SOC for longer life. Lithium batteries age faster if kept at their extremes. This would be discharged as well as fully charged.
Every persons needs are different so this approach may not be for everyone.

Jim

I thought Battleborn recommending topping the batteries off prior to storage?

[sanjoserob]

Great thread! Thank you so much for the info. I'm pretty much copying your chosen setup myself.

-My original post and questions were moved to their own thread.

[Guest]

I thought Battleborn recommending topping the batteries off prior to storage?

bellis,

Battleborn has some recommendations that really do not follow the common strategies for lithium care and operation, where most likely they do this for convenience. But the facts are, lithium batteries will last longer if stored close to their midpoint. I've also seen recommendations to not charge lithium batteries at freezing which is generally accurate. However this does not mean you can hammer the battery at a 1C charge at 33F and have no charge at 32F. It does not work this way as an example. The best way to charge a lithium battery is to have a charger that can customize the charge profile based on temperature. Since most chargers do not offer this capability, its best to charge at a lower rate at around 0.5C and to keep the battery in a heated or semi heated space to keep the battery above 40F. A battery heating pad can also be used to keep the battery temperature at a reasonable level. Trojan does the best job in illustrating a proper charge profile based on battery temperature in their manual that I've included here.
So in my case, the lithium battery is located in the passthrough where its in a semi heated space. The battery temperature is monitored with the Victron BMV712 where I will be alerted when the battery hits 45F.

Some with solar panels also will store their rigs and let the panels keep the battery(s) topped off. If there is a load on the system, the batteries will be exercised which will also shorten their life. Right now, my battery has been at a 50% SOC for a couple months where with no load on the system, it will remain in this state for a very long time.

Jim

[eodenc]

I got (2 runs of 8 AWG and a couple pull strings pulled from the entertainment center to the pass through yesterday (I have done a number of cable pulls in life; this one was not the worst, but not the easiest either).

I just got batteries and trying to determine my best option much of which depends on space and new wire runs. I've looked at where wiring is currently but no idea how hard it would be to run additional wire. Any tips would be appreciated.

[bellis]

bellis,

Battleborn has some recommendations that really do not follow the common strategies for lithium care and operation, where most likely they do this for convenience. But the facts are, lithium batteries will last longer if stored close to their midpoint. I've also seen recommendations to not charge lithium batteries at freezing which is generally accurate. However this does not mean you can hammer the battery at a 1C charge at 33F and have no charge at 32F. It does not work this way as an example. The best way to charge a lithium battery is to have a charger that can customize the charge profile based on temperature. Since most chargers do not offer this capability, its best to charge at a lower rate at around 0.5C and to keep the battery in a heated or semi heated space to keep the battery above 40F. A battery heating pad can also be used to keep the battery temperature at a reasonable level. Trojan does the best job in illustrating a proper charge profile based on battery temperature in their manual that I've included here.
So in my case, the lithium battery is located in the passthrough where its in a semi heated space. The battery temperature is monitored with the Victron BMV712 where I will be alerted when the battery hits 45F.

Some with solar panels also will store their rigs and let the panels keep the battery(s) topped off. If there is a load on the system, the batteries will be exercised which will also shorten their life. Right now, my battery has been at a 50% SOC for a couple months where with no load on the system, it will remain in this state for a very long time.

Jim

Jim:

That makes a lot of sense. My smartshunt and temp. monitor were just installed....as well as my multiplus. I believe (my stuff is all victron and BB) that the victron gear will adapt charging on both the multiplus and the solar charge controller to the ideal rate of charge. My batteries and gear are also in the pass through....so semi heated. Although with the weather we are having right now (been in the 90s every day) a cold battery is not a concern.

I need to post an update and some pics.