2021 Tab 400 - Batteries, BMV-712 settings, MPPT 75/15 settings, and power monitor routing

TomCanada

Hi All,

I've preordered our BMV-712 battery monitor & Progressive HW30C (interior) power monitor for our Tab 400 (due to arrive this spring!), and had some questions I was hoping the experts here might be so kind as to help share their expertise on:

- What brand/model are the batteries in the 2021 Tab 400?
- What's the absorption voltage on your solar controller (MPPT 75/15) configured to?  It looks like 14.4V is the default, but there's flexibility to modify this via the Bluetooth app based on what our battery actually calls for.  I'm curious if nuCamp tweaked this for the batteries or left it at default?  And if they left at a default different than our batteries spec, did you update it?
- What did you set your BMV-712's 'charged voltage' to?  According to Victron (https://www.youtube.com/watch?v=4ReljfO3k6M) this should be set to 0.3V below absorption voltage for solar systems (14.4 minus 0.3 = 14.1V if we're using 14.4V as the absorption voltage in the MPPT 75/15).  Which is quite a bit higher than the 0.3V below float voltage specified for non-solar setups.
- Similar question on the BMV-712 - they also recommend leaving the tail current to 4% and the Peukert exponent to 1.25 for generic lead-acid (though if the spec sheet for the batteries used on the Tab 400 specify it more explicitly, we could update it..).  Ditto for charge efficiency factor (default is 95% but if battery specs provide a better #, we could use it..).  Have any of you played with this value?
- For installing an internal surge protector/power monitor, is the 30A 120V feed into the camper easily accessible under the bed (driver-side panel), where the Nautilus and Alde live?  I'm considering wiring the HW30C in this area and routing the readout panel to the Nautilus compartment for easy viewing from exterior during setup.  But I haven't seen any photos of where the power actually feeds into the trailer.  On the exterior it's just to the left of the Nautilus but I can't tell if it would enter under the bed or under the fridge(3-way)/wardrobe, and how it routes to the converter (under the kitchen cabinets on the other/passenger side) from there.  Maybe it would be easier to install the power monitor somewhere behind the converter?

Thank you for any/all advice!

rhyno

Power comes in under the fridge(3-way)/wardrobe. You can remove the drawer between it and the lower cubby to access the area to mount an inline EMS there. 

jenniferlzr

rhyno said:

Power comes in under the fridge(3-way)/wardrobe. You can remove the drawer between it and the lower cubby to access the area to mount an inline EMS there. 

I'm going to attempt to install the EMS in my 2021 400. The access is under the wardrobe? 

TomCanada

jenniferlzr said:

rhyno said:

Power comes in under the fridge(3-way)/wardrobe. You can remove the drawer between it and the lower cubby to access the area to mount an inline EMS there. 

I'm going to attempt to install the EMS in my 2021 400. The access is under the wardrobe? 

That's what it sounds like.  Do you have your Tab already and can check?  Would love to see photos of what you're able to do!  Also would like to understand how they route the power to the converter.  If they go under the floor, that doesn't help - but if they go around the front (through the Coolcat compartment under the drivers side dinette seat) there's a chance of patching in there instead.

crampshaw

I have the BMV-712 monitoring 2 GC2 6v lead acids 5 yrs old. I use charge efficiency 90%, tail current 1.5%, charged voltage 13.2, and leave Peukert at 1.25. I show 100% state of charge just about the same time my Victron solar controller goes into float. 

rhyno

Here's a good write-up showing a hardwired EMS w/ pics.

https://tab-rv.vanillacommunity.com/discussion/11078/hardwired-hughes-power-watchdog-in-2021-t-b-400

TomCanada

rhyno said:

Here's a good write-up showing a hardwired EMS w/ pics.

https://tab-rv.vanillacommunity.com/discussion/11078/hardwired-hughes-power-watchdog-in-2021-t-b-400

Thanks Rhyno - that's very helpful!  I also got a (super fast) response from nuCamp and they were kind enough to send along some photos - looks like the 30A/120V power (orange cable) runs along the side of the under-fridge/wardrobe cubby, across the front of the under-bed area, and then tucks under the kitchen cabinets to reach the converter.  Lots of potential places to tap into the feed.  I particularly like though how it was done in the link you provided - so that might be the way to go.  Thanks again!

TomCanada

crampshaw said:

I have the BMV-712 monitoring 2 GC2 6v lead acids 5 yrs old. I use charge efficiency 90%, tail current 1.5%, charged voltage 13.2, and leave Peukert at 1.25. I show 100% state of charge just about the same time my Victron solar controller goes into float. 

Thanks!  Did you come up with those numbers by trial & error, or did you base them on the battery's specs?  The Victron solar controller will be a good way to monitor when it goes to float - did you keep the default aborption/float values in the solar controller (14.4V for absorption, 13.8V for float)?

jenniferlzr

TomCanada said:

jenniferlzr said:

rhyno said:

Power comes in under the fridge(3-way)/wardrobe. You can remove the drawer between it and the lower cubby to access the area to mount an inline EMS there. 

I'm going to attempt to install the EMS in my 2021 400. The access is under the wardrobe? 

That's what it sounds like.  Do you have your Tab already and can check?  Would love to see photos of what you're able to do!  Also would like to understand how they route the power to the converter.  If they go under the floor, that doesn't help - but if they go around the front (through the Coolcat compartment under the drivers side dinette seat) there's a chance of patching in there instead.

I've looked under the bed where the power comes in (I'm assuming it's the orange-covered wires), behind the lower drawer, and in the middle compartment of the bed. This last space looks like the easiest place to connect the EMS. I need to make sure the orange cord is the right one to cut!

ChrisFix

jenniferlzr said:

TomCanada said:

jenniferlzr said:

rhyno said:

Power comes in under the fridge(3-way)/wardrobe. You can remove the drawer between it and the lower cubby to access the area to mount an inline EMS there. 

I'm going to attempt to install the EMS in my 2021 400. The access is under the wardrobe? 

That's what it sounds like.  Do you have your Tab already and can check?  Would love to see photos of what you're able to do!  Also would like to understand how they route the power to the converter.  If they go under the floor, that doesn't help - but if they go around the front (through the Coolcat compartment under the drivers side dinette seat) there's a chance of patching in there instead.

I've looked under the bed where the power comes in (I'm assuming it's the orange-covered wires), behind the lower drawer, and in the middle compartment of the bed. This last space looks like the easiest place to connect the EMS. I need to make sure the orange cord is the right one to cut!

@jenniferlzr
Check out my install:
https://tab-rv.vanillacommunity.com/discussion/11078/hardwired-hughes-power-watchdog-in-2021-t-b-400
Installing behind the drawer below the wardrobe closet is a great location too. I didn't cut any factory wires.
I disconnected the wire from the back of the 30A Plug on the outside of the 400, and used that for the load side of the EMS. 
I then used a new short piece of 10 gauge copper wire (orange covered wire same as the factory) from the plug to the line side of the EMS.
Can be restored to factory in about 5 mins, with nothing but a screwdriver.

Denny16

Jennifer, the orange wire looks like the one you need to cut, if installing under the bed, you can bolt the unit to the ply bulkhead.  Easy location to access, but you loose some storage space.
cheers