watson1987
Well-known member
- Joined
- Jun 7, 2021
- Messages
- 428
- Fluid Motion Model
- R-31 S
- Hull Identification Number
- FMLT3119L718
- Vessel Name
- Clifford
- MMSI Number
- 368265640
Last spring I bought a new-to-me 2018 R31-S, and after 1 night on the hook, I quickly realized that the house bank was in desperate need for a refresh. The house bank registered 10.5V in the morning - thankfully the starter battery was enough to get us going - however, I learned that the starter and thruster batteries were shortly on their way out too. After some diagnosing to make sure it wasn't gremlins sucking back power, I decided to ditch AGM and go LifePO4.
I wanted to get some hours and nights on the boat before I shared my experience with this upgrade, and the approach I took, as I haven't seen anything quite like this before and didn't want to say it was working when it wasn't.
I created a wiring circuit that isolates the house battery bank when underway or when on shore power. The house bank is only drawn on in this case if for some reason the current draw is more than what is being supplied by either the alternator or inverter. This is handled by a few smart chargers from CTEK. The goal here was to allow charging to be truly turned off, while still providing house power, especially when so much time is spent on shore power. Besides the manual switch that I get into later, for normal operation I can simply unplug from shore power and not worry about the inverter drawing down my house bank. After the engine battery ACR switches off without the engine running, it can no longer provide power to the inverter, so it automatically turns off, but restarts if plugged back in to the store, or the engine turns on.
I had been using an older version of the D250SE on my truck for a camping fridge (secondary battery, plus solar charging) for 5 years, so I liked the performance and reliability of these devices.
https://smartercharger.com/products/ctek-smartpass-120s
https://smartercharger.com/collections/ ... tek-d250se
This was not a plug and play solution. In order to have a true separation of house loads, I had to run another 3/0 cable from the under-sink compartment back over to the port side battery locker, and re-do how the ACR wiring was done. The existing cable now supplies power to the house charging system from the engine, or supplies power back to this area so that the shore power can continue to charge both the engine and thruster batteries through the existing BlueSea ACRs. The new cable run supplies power from the house bank to the original house bank switch.
Each CTEK 120S provides input/outputs that allow 120amps of fast charging, but also 'pass through' current, which is where the isolation comes into play. Since the house bank can draw more than 120amps, I used 3 of these in parallel, which is more than the house bank breakers allow. The CTEK 250SE provides the intelligent charging at 20 amps for the LiFEPo4 batteries, only 1 is used in the system. The 250SE and 120S are designed to work in tandem as I have done, just typically three 120S are not required for such large house loads. I also removed the solar charging that was in the system and now run the solar panel directly into the CTEK 250SE. The problem with the old solar system, despite being dual bank, was that once the voltage increases on the ACRs, everything would open up anyway, making this functionality useless. Solar charging is now prioritized to the house bank, and the CTEK 250SE will also back trickle to the starter battery (and in turn the thruster) once the house bank is charged. Isolation of the house bank helps keep the house bank fully charged, as it is more efficient to use the solar immediately than to run off a battery and then charge back to full.
The three CTEK 120S can provide over 1000 amps of current (350amps each for 30 seconds) to the engine battery if it detects the need during starting. This prevents the need for a manual battery switch, while there is a small LED light that tells you this happened, it could mean you don't know your engine battery is dying, a benefit of knowing when you switch on the parallel switch of the original system.
Another downside of this system is that in order to run the inverter while on anchor, a manual switch is needed, as the CTEK system will not provide current back to the inverter from the input side (besides the jump start situation). The original on/off switch in the port side lazarette has been replaced when an on/off/on. While motoring, the inverter will run off alternator current. In addition, if this switch is not turned back, when connecting back to shore power the house bank will not be charged. In practice this has not been an issue, the odd time I need to use the microwave on anchor, I flip the switch, use it, and flip it off.
Rough diagram of the system. The shunt is a Victron Energy SmartShunt 500. What isn't pictured in this diagram is the extra 250amp fuse I added to the house loads. Both the fuses to the house load and the house bank are 250amp, I did this so I didn't have to carry any different spares compared to the ones for the thrusters. The solar charger input on the D250SE is also not pictured.
Getting it roughed in, everything was installed of a Starboard Plastics panel from TAP Plastics in Seattle (highly recommend this place). The on/off/on switch was not yet replaced in this photo.
Final install, the 4 batteries I used were Ampere Time LiFePO4 Deep Cycle Battery 12V 100Ah from Amazon.
As I mentioned, I had to replace the original engine and thruster battery, for reference I used NorthStar NSB-AGM31M for both of those
I wanted to get some hours and nights on the boat before I shared my experience with this upgrade, and the approach I took, as I haven't seen anything quite like this before and didn't want to say it was working when it wasn't.
I created a wiring circuit that isolates the house battery bank when underway or when on shore power. The house bank is only drawn on in this case if for some reason the current draw is more than what is being supplied by either the alternator or inverter. This is handled by a few smart chargers from CTEK. The goal here was to allow charging to be truly turned off, while still providing house power, especially when so much time is spent on shore power. Besides the manual switch that I get into later, for normal operation I can simply unplug from shore power and not worry about the inverter drawing down my house bank. After the engine battery ACR switches off without the engine running, it can no longer provide power to the inverter, so it automatically turns off, but restarts if plugged back in to the store, or the engine turns on.
I had been using an older version of the D250SE on my truck for a camping fridge (secondary battery, plus solar charging) for 5 years, so I liked the performance and reliability of these devices.
https://smartercharger.com/products/ctek-smartpass-120s
https://smartercharger.com/collections/ ... tek-d250se
This was not a plug and play solution. In order to have a true separation of house loads, I had to run another 3/0 cable from the under-sink compartment back over to the port side battery locker, and re-do how the ACR wiring was done. The existing cable now supplies power to the house charging system from the engine, or supplies power back to this area so that the shore power can continue to charge both the engine and thruster batteries through the existing BlueSea ACRs. The new cable run supplies power from the house bank to the original house bank switch.
Each CTEK 120S provides input/outputs that allow 120amps of fast charging, but also 'pass through' current, which is where the isolation comes into play. Since the house bank can draw more than 120amps, I used 3 of these in parallel, which is more than the house bank breakers allow. The CTEK 250SE provides the intelligent charging at 20 amps for the LiFEPo4 batteries, only 1 is used in the system. The 250SE and 120S are designed to work in tandem as I have done, just typically three 120S are not required for such large house loads. I also removed the solar charging that was in the system and now run the solar panel directly into the CTEK 250SE. The problem with the old solar system, despite being dual bank, was that once the voltage increases on the ACRs, everything would open up anyway, making this functionality useless. Solar charging is now prioritized to the house bank, and the CTEK 250SE will also back trickle to the starter battery (and in turn the thruster) once the house bank is charged. Isolation of the house bank helps keep the house bank fully charged, as it is more efficient to use the solar immediately than to run off a battery and then charge back to full.
The three CTEK 120S can provide over 1000 amps of current (350amps each for 30 seconds) to the engine battery if it detects the need during starting. This prevents the need for a manual battery switch, while there is a small LED light that tells you this happened, it could mean you don't know your engine battery is dying, a benefit of knowing when you switch on the parallel switch of the original system.
Another downside of this system is that in order to run the inverter while on anchor, a manual switch is needed, as the CTEK system will not provide current back to the inverter from the input side (besides the jump start situation). The original on/off switch in the port side lazarette has been replaced when an on/off/on. While motoring, the inverter will run off alternator current. In addition, if this switch is not turned back, when connecting back to shore power the house bank will not be charged. In practice this has not been an issue, the odd time I need to use the microwave on anchor, I flip the switch, use it, and flip it off.
Rough diagram of the system. The shunt is a Victron Energy SmartShunt 500. What isn't pictured in this diagram is the extra 250amp fuse I added to the house loads. Both the fuses to the house load and the house bank are 250amp, I did this so I didn't have to carry any different spares compared to the ones for the thrusters. The solar charger input on the D250SE is also not pictured.
Getting it roughed in, everything was installed of a Starboard Plastics panel from TAP Plastics in Seattle (highly recommend this place). The on/off/on switch was not yet replaced in this photo.
Final install, the 4 batteries I used were Ampere Time LiFePO4 Deep Cycle Battery 12V 100Ah from Amazon.
As I mentioned, I had to replace the original engine and thruster battery, for reference I used NorthStar NSB-AGM31M for both of those