Before we traded the old rig, I yanked out the batteries, battery monitor, inverter, and related accouterments (battery disconnect, catastrophic fuse, and circuit breaker).
The old setup was fairly simple:
To use the inverter, I would run an extension cord and backfeed the camper by plugging it into the shore power receptacle (with an adapter).
The new camper has a built-in generator and an automatic transfer switch. I have a few goals in mind with the new setup:
The idea is that I can parallel the batteries using bussbars for positive and negative. This will aid in better charging of each battery. I'll put a fuse onto each battery in order to protect each one and to be able to pull the fuses in order to isolate individual batteries.
I'll use either the Xantrex 15amp Automatic Transfer Switches or the KISAE 15amp Automatic Transfer switches.
For the future 12v loads, I'll introduce a fuse block that I'll be able to add and protect new 12v needs.
Click for full-size
My specific questions:
The old setup was fairly simple:
- wired 4 batteries in parallel
- added the battery monitor + inverter
- and tied into the camper's 12v system
To use the inverter, I would run an extension cord and backfeed the camper by plugging it into the shore power receptacle (with an adapter).
The new camper has a built-in generator and an automatic transfer switch. I have a few goals in mind with the new setup:
- get rid of the hokey extension cord + backfeeding of camper
- be able to provide power to most outlets in the camper
- better protect each individual battery
- be able to isolate down to a single battery (for yearly charge maintenance)
- provide an upgrade path for the future:
- adding solar charging
- adding a larger inverter
- make it easier to add additional 12v loads (TPMS repeater, basement lights, and USB outlets to the living room slide are on my immediate "to do" list)
- adding a subpanel for inverted vs. not inverted breakers
- adding solar charging
The idea is that I can parallel the batteries using bussbars for positive and negative. This will aid in better charging of each battery. I'll put a fuse onto each battery in order to protect each one and to be able to pull the fuses in order to isolate individual batteries.
I'll use either the Xantrex 15amp Automatic Transfer Switches or the KISAE 15amp Automatic Transfer switches.
For the future 12v loads, I'll introduce a fuse block that I'll be able to add and protect new 12v needs.
Click for full-size
My specific questions:
- are there specific recommendations you would make with all of this design?
- for the battery fuses, how many amps should they be?
- I previously opted for 1/0 between the batteries, 2/0 between the rest of the components, and 2awg to the inverter (just because it came w/ the inverter). Are these wire sizes sufficient for now and the future?
ependydad wrote:
Ok, I've revised the diagram with a couple of updates:
- I noticed my charger was bypassing the battery disconnect and worse was also bypassing the shunt so it wouldn't be counted.
- I tried to add clarity to the 15amp transfer switches
- I tried moving the charging points so they would more equally balance the batteries
Click for full-size
1. battery disconnect is in the preferred place, if you place it in the positive line the battery positive terminals are still hot and a wrench from a terminal to chassis will result in fireworks.
the automotive industry worked this out a long time ago which is why they tell you to disconnect the negative side first.
2. there should be a strap from the shunt to chassis at one point only, either at the shunt or the negative buss bar as drawn or at the campers distribution panel. one and one only.
3. power takeoff. as you are using lithium drop-ins, you will not have the issues lead acid suffer from in parallel. as drawn the positive take off should be on the bottom battery terminal and the negative should be on the top battery terminal.
4. fuse to the inverter is on the small size. inverters are at best 90% efficient so at full load you will have approx ( 1000 * 1.1 ) / 12 = 91.6 Amps.. your 80 A breaker will most likely trip.
5. there is no fuse in the converter positive line, hopefully there is one inside the converter itself.
ependydad wrote:I hope you don't mind but I see a few things that could be changed--I'd suggest to locate your shunt between (-) bus bar and frame. I'd also move the disconnect to the (+) polarity but that's just me.
Ok, I've revised the diagram with a couple of updates:
- I noticed my charger was bypassing the battery disconnect and worse was also bypassing the shunt so it wouldn't be counted.
- I tried to add clarity to the 15amp transfer switches
- I tried moving the charging points so they would more equally balance the batteries
Click for full-size
Between the devices and 12V supply there should be circuit protection.
Ok, I've revised the diagram with a couple of updates:
Click for full-size
- I noticed my charger was bypassing the battery disconnect and worse was also bypassing the shunt so it wouldn't be counted.
- I tried to add clarity to the 15amp transfer switches
- I tried moving the charging points so they would more equally balance the batteries
Click for full-size
time2roll wrote:ependydad wrote:
Do you have any recommendations for bussbars to buy?
https://www.bluesea.com/products/2126/MaxiBus_250A_BusBar_-_Six_5_16in-18_Studs
Unless you need 600 amp rating....
Honestly, I have no idea what amp rating I need. How do I figure that out?
Each battery is 100amp hours paralleled to remain at 12v and the inverter is 1000W.
ependydad wrote:
Do you have any recommendations for bussbars to buy?
https://www.bluesea.com/products/2126/MaxiBus_250A_BusBar_-_Six_5_16in-18_Studs
Unless you need 600 amp rating....
