Mobile cart build

[OffGridForGood]

SOOOOOO - ya should have built two at once? (one to keep)

 

[EastTexCowboy]

SOOOOOO - ya should have built two at once? (one to keep)

I thought about that. But I figured I'd learn on this one then keep the 2.0 version for myself!

Seriously though, I don't know that I would do a lot differently. There are couple of things that bug me but I can't figure an easy way around them.
1. The 3KW only allows you to set the SOC "switch to grid" setting at a maximum of 50%. For this thing I'd like to set it higher or figure out some way to get it to charge at will to top it off. This is assuming no PV, which is probably how my daughter will use it. The only other alternative is a 48v charger or a chargeverter.
2. The inverter requires a minumum of 120v before it will start using solar. That's gonna be three panels that are in the 40v + range. For something that's only for emergency use that seems overkill. Didn't you say you hung one panel on the side a building and charge yours with it? Which inverter are you using?

 

[OffGridForGood]

I thought about that. But I figured I'd learn on this one then keep the 2.0 version for myself!

Seriously though, I don't know that I would do a lot differently. There are couple of things that bug me but I can't figure an easy way around them.

It looks good, I doubt you need to change anything!

1. The 3KW only allows you to set the SOC "switch to grid" setting at a maximum of 50%. For this thing I'd like to set it higher or figure out some way to get it to charge at will to top it off. This is assuming no PV, which is probably how my daughter will use it. The only other alternative is a 48v charger or a chargeverter.

I'm not sure about this model, but some of the MPP's have a setting for 'back to solar first' after charging to "FUL" ie fully charged. I have used this in the wost part of winter when I am charging off peak at night, and just want it to go to 100% then switch back to solar first for the next day -without me needing to touch anything, so I can set it and forget it. Check if you have a "FUL" option for return to solar after charging.

Edit: in the MPP 6048 setting #13 'Setting voltage back to battery mode' there is a list of voltages, and the last one is "FUL" which they define based on the battery charging voltages you set up for the inverter.

2. The inverter requires a minumum of 120v before it will start using solar. That's gonna be three panels that are in the 40v + range. For something that's only for emergency use that seems overkill. Didn't you say you hung one panel on the side a building and charge yours with it?

see below:

Which inverter are you using?

I use the MPP 2724 - bit less output than the 3k but will charge with just one 440 panel

 

[Shimmy]

2. The inverter requires a minumum of 120v before it will start using solar. That's gonna be three panels that are in the 40v + range. For something that's only for emergency use that seems overkill. Didn't you say you hung one panel on the side a building and charge yours with it? Which inverter are you using?

Yeah, these cart builds really need an AIO that can work closer to 70V IMO. You could concievably add a lip to hold ~8x100W panels which would add about 12" depth to the unit...

 

[OffGridForGood]

Here is the short brochure for the MPP 2724
It needs a few volts over the battery voltage to start charging, max 60VOC and max 750W
Some will not like the tiny wattage permitted, but for my application I loved it, one single 440 panel does what I need. Two in parallel would be 'over paneled' but would work well too.

 

[Shimmy]

Here is the short brochure for the MPP 2724
It needs a few volts over the battery voltage to start charging, max 60VOC and max 750W
Some will not like the tiny wattage permitted, but for my application I loved it, one single 440 panel does what I need. Two in parallel would be 'over paneled' but would work well too.

That is a great little inverter for an emergency cart! A little heavier than the EG4, but a few things that seem to make up for it like the built-in outlets.

https://watts247.com/manuals/mpp/PIP-LV-MR/PIP-LV-MR%203K%20manual-20200428.pdf?x46339

 

[EastTexCowboy]

Here is the short brochure for the MPP 2724
It needs a few volts over the battery voltage to start charging, max 60VOC and max 750W
Some will not like the tiny wattage permitted, but for my application I loved it, one single 440 panel does what I need. Two in parallel would be 'over paneled' but would work well too.

Wish I had looked at this inverter. But it's done now so it will just have to do. Not that the EG4 is bad, but this might be a better option for a cart. Of course if she decides she's just going to charge it off the grid it won't matter.

 

[OffGridForGood]

Wish I had looked at this inverter. But it's done now

AND version 2.0 is coming next!

From the postings everyone did during this build, I like the following: (and proper credit to all for the ideas)
- garden cart with four big tires to allow use all over the property, stable and can't fall over.
- welded in angle iron slots to hold one or two rack batteries, easily removalble to be deployed elsewhere, secure with the tabs.
- the idea of a small storage area for a cart or garden wagon using PV panels for the roof - sized to charge the moble unit.
I like the 2724 - been using this awhile and it will run a wire feed welder, start and run a wormdrive 8" skillsaw, a grinder, etc. (needs at least 150A output battery to do this, ie two 100A racks would work, I use a DIY 304Ah 8s).
The plugs are built right on the side of this AIO - four plugs (very handy) plus it has a few USB plugs for phone charging etc. The 2724 does not support parallel, and is limited to 750W charging. It would be a good option for a small trailer too.
In my use, the wagon has a parking spot beside a wall mounted 440W panel, and since it has MC-4's right on the AIO I just park and plug it in when not in use. Usually it has lots of time to charge before I need it again, if not there is the 120v input for faster charging.

 

[EastTexCowboy]

AND version 2.0 is coming next!

For the postings everyone did during this build, I like the following: (and proper credit to all for the ideas)
- garden cart with four big tires to allow use all over the property, stable and can't fall over.
- welded in angle iron slots to hold one or two rack batteries, easily removalble to be deployed elsewhere, secure with the tabs.
- the idea of a small storage area for a cart or garden wagon using PV panels for the roof - sized to charge the moble unit.
I like the 2724 - been using this awhile and it will run a wire feed welder, start and run a wormdrive 8" skillsaw, a grinder, etc. (needs at least 150A output battery to do this, ie two 100A racks would work, I use a DIY 304Ah 8s).
The plugs are built right on the side of this AIO - four plugs (very handy) plus it has a few USB plugs for phone charging etc. The 2724 does not support parallel, and is limited to 750W charging. It would be a good option for a small trailer too.
In my use, the wagon has a parking spot beside a wall mounted 440W panel, and since it has MC-4's right on the AIO I just park and plug it in when not in use. Usually it has lots of time to charge before I need it again, if not there is the 120v input for faster charging.

I may go back and do a garden wagon setup someday. Frankly, I don't know that I'd use it enough to justify it. I have cordless just about everything and a Miller Bobcat 250 I can put on the trailer if I really need to work out in the pastures. But they are just cool. I remember looking at the MPP inverter after thinking about it and I wanted to stay 48v just to be compatible with existing batteries. Another thought I've had is whenever I upgrade my existing system I'll have two MPP LV6548 inverters I'm going to need to repurpose. I might try to get creative with one or both of those. Agreed on all the great suggestions. This is one of the best places to collaborate and brainstorm.

 

[G00SE]

I hate this forum sometimes. ?

Just bought 2 SRNE 5k on sale so that I can do a couple of these builds.

 

[EastTexCowboy]

I'm not sure about this model, but some of the MPP's have a setting for 'back to solar first' after charging to "FUL" ie fully charged. I have used this in the wost part of winter when I am charging off peak at night, and just want it to go to 100% then switch back to solar first for the next day -without me needing to touch anything, so I can set it and forget it. Check if you have a "FUL" option for return to solar after charging.

Edit: in the MPP 6048 setting #13 'Setting voltage back to battery mode' there is a list of voltages, and the last one is "FUL" which they define based on the battery charging voltages you set up for the inverter.

Setting #13 on the 3KW has a FUL setting but it also has a note - This is ONLY for AGM and FLD battery types.

 

[OffGridForGood]

Yeah, these cart builds really need an AIO that can work closer to 70V IMO. You could concievably add a lip to hold ~8x100W panels which would add about 12" depth to the unit...

I thought about making an even smaller one, using the MPP 1012, but decided to go with the 2724 for running some bigger stuff like corded tools and a small pump at my cabin. I think with the 1012 and a small battery I could make a back-pack one, put a small alum frame on it so it will stand up on the ground once you get where your going with it. Would be a cool unit for camping, provide lights and some power for a night or two on a fully charged battery. Really no limit to what you can do with these AIO units.

 

[OffGridForGood]

Another thought I've had is whenever I upgrade my existing system I'll have two MPP LV6548 inverters I'm going to need to repurpose. I might try to get creative with one or both of those. Agreed on all the great suggestions. This is one of the best places to collaborate and brainstorm.

I am thinking the same way, in a couple of years (maybe less!) upgrading my current inverters to a couple of 12k or 15k, then repurpose the MPP's I have now for more portable type of 'moble generator' set up.
I sure like the idea of a closed in twin axel trailer, with maybe 6 panels on the top, and 6 down one side that can tilt up at the destination, the side lifts up to make a covered outside work area, and the ones on the roof tilt up about 30-degrees to catch the sun in summer. That would be 12 panels, about 6kW of collection. Stick one inverter inside and some batteries in a sealed case that slides under the floor between the trailer rails. That could be very workable set up. Heck put a shore power plug on the side, and an EV charger adapter so you can fast charge the trailer battery at those free public charging stations LOL.

 

[G00SE]

I sure like the idea of a closed in twin axel trailer, with maybe 6 panels on the top, and 6 down one side that can tilt up at the destination, the side lifts up to make a covered outside work area, and the ones on the roof tilt up about 30-degrees to catch the sun in summer. That would be 12 panels, about 6kW of collection. Stick one inverter inside and some batteries in a sealed case that slides under the floor between the trailer rails. That could be very workable set up. Heck put a shore power plug on the side, and an EV charger adapter so you can fast charge the trailer battery at those free public charging stations LOL.

? I like the way you think. If you do a 24ft box you can fit 8 on top and 8 on side if you lay them 2x2 (providing they are 60/120 panels) can get by with 7ft wide unless you prefer 8. I can only do 4 and 4 on mine with a 14ft box. Wish mine was 18ft so I could fit 6 like you reference. Cost me more to buy another trailer than just make do
Then just run a mini split up front to keep the batteries happy and call it a day

 

[OffGridForGood]

? I like the way you think. If you do a 24ft box you can fit 8 on top and 8 on side if you lay them 2x2 (providing they are 60/120 panels) can get by with 7ft wide unless you prefer 8. I can only do 4 and 4 on mine with a 14ft box. Wish mine was 18ft so I could fit 6 like you reference. Cost me more to buy another trailer than just make do
Then just run a mini split up front to keep the batteries happy and call it a day

I have the trailer already, and yup 18-foot, and it is about 7 feet wide on the roof, so this would work well I think. The trailer is the taller version (so lights can be attached down the middle without bumping your head) and I think this added height will allow the side fold-up section I am dreaming about to be high enough, even with a slope for the sun angle, and still be tall enough when standing on the ground beside the trailer.
I was thinking to make the folding section in two parts, three panels each, so they are not as heavy for lifting up. I ordered a couple of linear actuators to try out, see if these can lift the side panel. Darn linear actuators are 12v DC (I couldn't find any 48-volt ones) so I would need to install a buck inverter to get the proper voltage for the lifts. not the end of the world I suppose.

And for me, no A/C needed, maybe a diesel heater thou!

 

[EastTexCowboy]

I have the trailer already, and yup 18-foot, and it is about 7 feet wide on the roof, so this would work well I think. The trailer is the taller version (so lights can be attached down the middle without bumping your head) and I think this added height will allow the side fold-up section I am dreaming about to be high enough, even with a slope for the sun angle, and still be tall enough when standing on the ground beside the trailer.
I was thinking to make the folding section in two parts, three panels each, so they are not as heavy for lifting up. I ordered a couple of linear actuators to try out, see if these can lift the side panel. Darn linear actuators are 12v DC (I couldn't find any 48-volt ones) so I would need to install a buck inverter to get the proper voltage for the lifts. not the end of the world I suppose.

And for me, no A/C needed, maybe a diesel heater thou!

Since we're throwing all our ideas out there I'll add this one. I've thought about building something on, for lack of a better term, a pallet. Something I could pick up with the forks and take it wherever I needed it. Out in the pasture, beside the shop or the house, or set it on a trailer and go on the road. With any substantial amount of batteries these things get heavy. Even this little cart is more than I would want to try to load by myself at somewhere around 150 lbs. I try to get stuff on pallets whenever I can or I'll take an empty pallet with me when I go to pick up heavy stuff so I can offload with one of the tractors and pallet forks. This kind of setup would let me have a pretty robust battery bank.

But it's not gonna happen until I get my home system upgraded so maybe in a couple of years if I'm still as crazy as now.

 

[OffGridForGood]

Setting #13 on the 3KW has a FUL setting but it also has a note - This is ONLY for AGM and FLD battery types.

Well, We Tried!

Since we're throwing all our ideas out there I'll add this one. I've thought about building something on, for lack of a better term, a pallet. Something I could pick up with the forks and take it wherever I needed it. Out in the pasture, beside the shop or the house, or set it on a trailer and go on the road. With any substantial amount of batteries these things get heavy. Even this little cart is more than I would want to try to load by myself at somewhere around 150 lbs. I try to get stuff on pallets whenever I can or I'll take an empty pallet with me when I go to pick up heavy stuff so I can offload with one of the tractors and pallet forks. This kind of setup would let me have a pretty robust battery bank.

But it's not gonna happen until I get my home system upgraded so maybe in a couple of years if I'm still as crazy as now.

That is a great idea, fork lift pockets or a pallet for the base. make sure it will fit in the truck box, and you got power to go anywhere you can drive the truck or the tractor!
See even you caught the bug from your own build!
I keep thinking of ways to make a mobile unit more waterproof, my wagon is not at all water proof and this has lead to a few 'close calls' ie going to have a bite of lunch with the cart out in the pasture, is that rain I hear...brb! yeah, so I toss a tarp over it sometimes now. Something a bit more like a roof - solar panel roof? lol set on a pallet is a great idea. stable and easy to pick up with equipment.
now ya got my mind going again Damn you ETC!

 

[EastTexCowboy]

Well, We Tried!

That is a great idea, fork lift pockets or a pallet for the base. make sure it will fit in the truck box, and you got power to go anywhere you can drive the truck or the tractor!
See even you caught the bug from your own build!
I keep thinking of ways to make a mobile unit more waterproof, my wagon is not at all water proof and this has lead to a few 'close calls' ie going to have a bite of lunch with the cart out in the pasture, is that rain I hear...brb! yeah, so I toss a tarp over it sometimes now. Something a bit more like a roof - solar panel roof? lol set on a pallet is a great idea. stable and easy to pick up with equipment.
now ya got my mind going again Damn you ETC!

If we could get @timselectric onboard, we might even come up with a way to make it self-propelled ... just sayin'

 

[OffGridForGood]

If we could get @timselectric onboard, we might even come up with a way to make it self-propelled ... just sayin'

I can just about see it...
1-ton dually EV-conversion with built in on board 120-240 inverters and 200kWh pack...with a solar roof!

 

[BuffaloTrace]

Here is the short brochure for the MPP 2724
It needs a few volts over the battery voltage to start charging, max 60VOC and max 750W
Some will not like the tiny wattage permitted, but for my application I loved it, one single 440 panel does what I need. Two in parallel would be 'over paneled' but would work well too.

I used free dumpster 2 x 220w 52voc panels in parallel and works great. I've really enjoyed using this mpp2748 and homebuilt lifepo4. If it hadn't worked out so well I probably would not be designing, and slowly acquiring bargains for a larger build.