Jack
Senior Member
Edited after follow-on postings - thanks everyone. Most pictures have disappeared - I'll try and get them back in.
I installed a DC-DC Charger in our 2015 Fleet front dinette for two reasons: 1. The 2019 Ford Ranger alternator is “smart”. 2. I will soon switch to a Lithium battery and my Iota can’t be reconfigured for Lithium and replacing the Iota would be a nightmare.
A smart alternator is voltage controlled by the ECU, which, after charging the truck battery, usually keeps the voltage in the range of about 12.5 to 13.5. This is fine for normal loads which demand current and don’t care much about voltage as long as it’s reasonable. The load of a charging battery, however, varies with voltage.
There’s a good explanation at: https://www.redarc.com.au/alternator-vs-fixed-alternator.
The Iota outputs 13.6 V except when bulk charging. This is fine for AGM batteries, but Lithium batteries want a higher voltage to reach full charge in a reasonable amount of time. This is somewhat battery dependent. The LifeBlue batteries, according to their manufacturer, needs 13.8 V for reasonable charging. I want more than 150 Ah and only the LifeBlue (200 Ah) and the Renogy (170 Ah) lithium have a form factor that will fit in the front dinette battery compartment.
I chose the Victron DC-DC 30 A Charger over the Redarc and the Renogy. The Redarc unit includes an MPPT Charge Controller but it is 25 A and does not have remote temperature sensing (I couldn’t find it, anyway). The separate Redarc display only shows voltages. You would be better off with a simple V-A display unit from Amazon – or what’s really the best is a true battery monitor (go with the Victron). The Victron DC-DC Charger is 30 A and is monitored and controlled over a very reliable and robust Bluetooth Since I already have the Victron MPPT Charge Controller only the Renogy would be cheaper, by about $30. The two Victron 30 A units will set you back about $420 (+$40 for remote sense). Add $25 for a display for the Victron or Renogy. The Redarc, without display, is about $380.The Victron units are microprocessor controlled and also get over-the-air updates. The MPPT charge controller has the remote temperature and voltage sense (a separate Bluetooth unit) and this is planned for the DC-DC Charger. It will simply be an OTA update. Since everything you might want to know about the MPPT and the DC-DC are availbale via Bluetooth and my old Clipper Battery Monitor gives a quick status view of voltage and current.
The Victron DC-DC Charger and MPPT Charge Controller are much more capable than the Redarc and Renogy – you can even use 12 gauge wire to the battery on the MPPT Charge Controller since it has remote voltage sense and will adjust the voltage output to compensate for the varying voltage drop on whatever gauge wire you have.
The killer reason to go with the Victron DC-DC Charger – no need for an engine-running sense wire from the camper to the truck. Both the Redarc and the Renogy appear to need one. On the Victron, you set voltage levels (a hysteresis for on and off) to detect engine-running.
One caution on the Victron units. You need to be comfortable setting them up with the Victron App on your cell phone or tablet (iPhone or Android). As shipped from the factory, you will need to configure a number of settings.
Other notes on the Victrons. I went with 30 A. They are large – the case is the same as the 50 A units. The 20 A units are much smaller (and cheaper).
Wiring the DC-DC From the Truck:
Most recent campers should have similar wiring. I strongly recommend a circuit breaker for you battery such as https://www.amazon.com/gp/product/B07PBGMMNZ/ref=ppx_yo_dt_b_search_asin_title?ie=UTF8&psc=1 . This also acts as a convenient disconnect switch.
My Iota is AGM only, so I wired it to the DC-DC Charger as well. When I switch to a Lithium battery, the Iota will still do the job.
With equipment that I might need to get to (and who knows what changes I might want to make later), I have connectorized all of the wiring to the front panel. This included terminal strips to cleanup the ground and 12 V wiring connections. I also replaced the screw with a nut and bolt on the drawer track so the track can be installed after attaching the panel. When the camper was new, I used a piece of thin aluminum flashing to wedge the drawer end of the panel past the weather stripping around the door. Over time, this became much easier. The drawer track, on the other hand was always a PIA.
I installed a DC-DC Charger in our 2015 Fleet front dinette for two reasons: 1. The 2019 Ford Ranger alternator is “smart”. 2. I will soon switch to a Lithium battery and my Iota can’t be reconfigured for Lithium and replacing the Iota would be a nightmare.
A smart alternator is voltage controlled by the ECU, which, after charging the truck battery, usually keeps the voltage in the range of about 12.5 to 13.5. This is fine for normal loads which demand current and don’t care much about voltage as long as it’s reasonable. The load of a charging battery, however, varies with voltage.
There’s a good explanation at: https://www.redarc.com.au/alternator-vs-fixed-alternator.
The Iota outputs 13.6 V except when bulk charging. This is fine for AGM batteries, but Lithium batteries want a higher voltage to reach full charge in a reasonable amount of time. This is somewhat battery dependent. The LifeBlue batteries, according to their manufacturer, needs 13.8 V for reasonable charging. I want more than 150 Ah and only the LifeBlue (200 Ah) and the Renogy (170 Ah) lithium have a form factor that will fit in the front dinette battery compartment.
I chose the Victron DC-DC 30 A Charger over the Redarc and the Renogy. The Redarc unit includes an MPPT Charge Controller but it is 25 A and does not have remote temperature sensing (I couldn’t find it, anyway). The separate Redarc display only shows voltages. You would be better off with a simple V-A display unit from Amazon – or what’s really the best is a true battery monitor (go with the Victron). The Victron DC-DC Charger is 30 A and is monitored and controlled over a very reliable and robust Bluetooth Since I already have the Victron MPPT Charge Controller only the Renogy would be cheaper, by about $30. The two Victron 30 A units will set you back about $420 (+$40 for remote sense). Add $25 for a display for the Victron or Renogy. The Redarc, without display, is about $380.The Victron units are microprocessor controlled and also get over-the-air updates. The MPPT charge controller has the remote temperature and voltage sense (a separate Bluetooth unit) and this is planned for the DC-DC Charger. It will simply be an OTA update. Since everything you might want to know about the MPPT and the DC-DC are availbale via Bluetooth and my old Clipper Battery Monitor gives a quick status view of voltage and current.
The Victron DC-DC Charger and MPPT Charge Controller are much more capable than the Redarc and Renogy – you can even use 12 gauge wire to the battery on the MPPT Charge Controller since it has remote voltage sense and will adjust the voltage output to compensate for the varying voltage drop on whatever gauge wire you have.
The killer reason to go with the Victron DC-DC Charger – no need for an engine-running sense wire from the camper to the truck. Both the Redarc and the Renogy appear to need one. On the Victron, you set voltage levels (a hysteresis for on and off) to detect engine-running.
One caution on the Victron units. You need to be comfortable setting them up with the Victron App on your cell phone or tablet (iPhone or Android). As shipped from the factory, you will need to configure a number of settings.
Other notes on the Victrons. I went with 30 A. They are large – the case is the same as the 50 A units. The 20 A units are much smaller (and cheaper).
Wiring the DC-DC From the Truck:
Most recent campers should have similar wiring. I strongly recommend a circuit breaker for you battery such as https://www.amazon.com/gp/product/B07PBGMMNZ/ref=ppx_yo_dt_b_search_asin_title?ie=UTF8&psc=1 . This also acts as a convenient disconnect switch.
- For the Victron, download the VictronConnect App for your phone.
- Replace the 30 A thermal breaker near your truck battery and depending on the wiring to the camper, with a 40 A (10 gauge wire) or 50 A (8 gauge).
- Check the voltage on the “Main Bat” terminal of your battery separator – it should be the truck battery voltage. If not, stop here and troubleshoot or get help. Label the wires connected to the battery separator with tape (“Aux” and “Main”). in case you have to troubleshoot.
- Unplug the camper from the truck or disconnect the positive wire to the camper from the truck battery (or from the auto-reset fuse). Open the circuit breaker or disconnect the wire from positive terminal of the camper battery and tape the end. If you have solar, disconnect the panels. You may be able to unplug the panel(s) on the roof, or disconnect the positive wire from the charge controller and tape the end so it can’t short out accidentally.
- Find a location to mount you DC-DC Charger. Unless the DC-DC has remote voltage sense or adjustable charge voltages, the closer to the battery or the thicker the wire gauge, the better. If you can do the math to adjust the voltages, you can use 10 or even 12 gauge wire with the Victron. NOTE: The Victron can get hot, so make sure it has air flow.
(needed to modify this panel)
- Disconnect the wire from the “Main Bat” terminal of the battery separator. Connect this wire (or an extension to it) to the input on your DC-DC charger.
- If there are two wires connected to “Aux Bat” post on the battery separator, disconnect them from the battery separator and connect them together. One should go to a 30 A auto-reset fuse – you can leave the fuse in the circuit or remove it. Be sure to tape the connection. If there is only one wire, disconnect and tape it. The Eaton 1341A battery separator has a black wire connected to a spade post. Disconnect it and tape the end.
Sorry, forgot to take before pictures.
- Connect the output of the DC-DC Charger to your battery. If the DC-DC is not isolated(most likely), connect the single common ground terminal to the battery. If there are two ground terminals on the DC-DC, connect them together and then to the battery.
- Reconnect the camper to the truck (or connect the camper wire to the truck battery). Verify that you see the truck battery voltage on the input to the DC-DC controller. If not, check your wiring – trace the voltages from the truck to find the problem.
- For the Victron, with the engine running, open the App and set your parameters for battery type and engine running levels. The default Bluetooth pin is 000000. (The Victron website has detailed instructions on setting up and using the App.) You can change the Pin now or later. For a new Pin, choose something easy to remember – like your birth date in 6 digits. Write the Pin on a label and stick it on the controller. Also write the PUK number on the DC-DC Charger on the label as well. The PUK resets the Pin code to 000000.
- If you don’t already have a circuit breaker now is the time to add it. Close the circuit or connect the wire back to the positive terminal of the battery.
- Measure the battery voltage. Start your truck again, and verify that the voltage at the battery is greater. With the Victron, just check your App to verify the DC-DC Charger is charging the battery.
My Iota is AGM only, so I wired it to the DC-DC Charger as well. When I switch to a Lithium battery, the Iota will still do the job.
- Open the circuit breaker or disconnect the wire from positive terminal of the camper battery and tape the end so it can’t short out accidentally.
- The positive wire from the Iota went straight to the fuse block. On my Fleet, I could, with some difficult peering into the warren of wires at the bottom of the cabinet, trace it to the fuse block. (Unscrew the fuse block and pull it partway out to see behind it.) It was the lower of the two white wires coming into the input of the fuse block. See pictures.
- Disconnect this wire. Connect the camper to shore power and verify that you have 13.6 V on this wire (make sure the 120 V circuit breakers closed). Disconnect shore power
(Bottom wire already removed).
- Add an extension to this wire to reach the DC-DC Charger. Connect it to the positive terminal, along with the wire from the truck alternator. Note that when connected in parallel, the Iota will also be charging your truck battery at 13.6 V. I actually wired the two inputs to a relay activated by the Iota. It’s not needed, but it was, easy, cheap and accommodated my sensibilities.
- Close the circuit breaker at the battery or connect the wire to the positive terminal.
- Measure the battery voltage. Connect the camper to shore power and verify that the voltage at the battery is greater. With the Victron, just check your App to verify the DC-DC Charger is charging the battery.
With equipment that I might need to get to (and who knows what changes I might want to make later), I have connectorized all of the wiring to the front panel. This included terminal strips to cleanup the ground and 12 V wiring connections. I also replaced the screw with a nut and bolt on the drawer track so the track can be installed after attaching the panel. When the camper was new, I used a piece of thin aluminum flashing to wedge the drawer end of the panel past the weather stripping around the door. Over time, this became much easier. The drawer track, on the other hand was always a PIA.
