HRowland
Well-known member
- Joined
- Feb 28, 2011
- Messages
- 463
- Fluid Motion Model
- C-24 C
- Non-Fluid Motion Model
- 2008 Nordic Tug 37
- Vessel Name
- Catnip
- MMSI Number
- 368024230
As delivered by Ranger Tugs my R27 has 3 group 27 deep cycle batteries (Centennial DC27MF, 90AH). Two were connected in parallel for the House bank, the third was the Thruster/Windlass bank. The engine start battery is a group 27 marine starting type (Centennial 27SM-8MF). The factory installation provided 180AH for the house bank.
As an Electrical Engineer it bothered me that an additional 90AH capacity was sitting unused most of the time, except for a number of seconds of thruster use and a few minutes of windlass use. I researched this and learned that modern thinking is to combine separate banks (except for the engine start battery) into a single large bank when possible. Nigel Calder is an advocate of this, as are many ABYC certified marine electricians. An exception would be for very large bow thrusters which require a large battery bank located next to the thruster, in many cases this would also be 24V. In our case we have a small thruster with a nominal current draw of 195A per Imtra specification, which allows the thruster battery to be remote and connected via 1G cable. In a multi battery bank is is also important to balance the current in/out of the batteries for best lifetime and efficiency. There are several methods to do this, I chose to use individual cables to each battery rather than "daisy chaining" them. This allowed me to use 1G cable everywhere and still handle the current used by the thrusters with minimal voltage drop or cable heating.
I also wanted to install a smart battery monitor that would provide a more accurate "gas gauge" than a simple volt meter. I selected the Victron BMV600S which can monitor up to 500A and provides data on AH consumed, battery state of charge as a percentage, voltage, and much more. It has audible and visual alarms that can be set to specified discharge level and/or voltage. It includes a 500A shunt which monitors current in/out of the monitored bank so it can compute AH in and out.
The battery charger (ProMariner ProNautic 1220P) is a smart multi bank charger that has a remote temperature probe to compensate the voltages used during the various charge phases, but the cable length only allowed this to reach the engine start battery. This battery typically requires the least amount of charging. It would be better to monitor the temperature of a house battery. In practice this is probably a minor point, the batteries probably stay at nearly identical temperatures unless the house bank is used at high discharge or charge rates. The Automatic Charge Relay negates the multi bank feature of the charger, more on this later.
After this research I decided to combine the house and thruster banks to have a single 270AH bank for the house, thrusters, windlass, etc.- everything except engine start. This required reconfiguration of the battery connections, installation of larger bus bars, and connection of the Victron battery monitor. To allow the battery charger temp sense probe to be on a house battery I moved the engine start battery to a different location in the battery compartment. I had to move the engine fuse forward a bit to allow the cables to reach the new position.
I needed to make heavy duty cables, using mostly 1G marine grade Red and Yellow battery cable. More research pointed me to the right direction on this and I found an excellent tutorial on crimping battery lugs. The proper crimp tool costs more than a cheap Ancor hammer crimper but does a significantly better job. I also learned there are different grades of battery cable lugs, I chose to use heavy duty lugs, not the typical Ancor lugs that you see everywere. See http://www.pbase.com/mainecruising/battery_cables for a great tutorial.
FTZ Heavy Duty lug crimp tool that I used. The handles are about 2 feet long to allow easy crimping. The rotating dies allow crimping lugs for wire sizes 6G to 4/0G. It makes a diamond shaped crimp and actually reduces the diameter of the lug to compress against the wire. A tip that I learned is to repeat each crimp after rotating the lug 90 degrees. This smooths a sharp edge left on two of the points left by the crimp tool.
FTZ Heavy Duty lugs, these are very thick walled, tin plated copper. When crimped properly the battery cable cold forms to the lug for an air tight connection. I obtained these from Fisheries Supply. The lugs are labled and have a color code that matches a table on the crimp tool so you can select the proper dies.
Example of a completed battery cable end. The heavy duty adhesive lined heat shrink tubing seals the lug and the end of the cable. I used a Brother P-touch to make the labels and protected this with clear heat shrink. The battery lug and cable has a lot of mass and is slow to heat. I found that I got the best adhesive melting on the lug side by pre-heating the lug before sliding the tubing over it and then shrinking. You want to see some the adhesive melting and flowing slightly out the ends of the tubing. I found that Gregs Marine Wire Supply is a good source for quality marine wire, http://gregsmarinewiresupply.com/Zen/.
All of the house/thruster +12V connections are on a 600A 4 position Blue Sea bus bar. Connections are the alternator, one side of the Automatic Charge Relay, Genset, Thruster feed to switch, House feed to switch, Inverter, 3 batteries, and +12V to the Victron circuit board on the shunt. To balance the current between the three batteries I used a seperate 1G jumper for each one. A Blue Sea protective cover prevents accidental shorting to the +12V.
House/Thruster 600A 4 position +12V battery bus bar
The Victron 500A shunt is mounted to a piece of starboard. The starboard is bonded to the hull in the battery compartment. One side has 3 1G cables to the batteries (to keep the current balanced), the other has a pair of 1G jumpers to the ground bus bar. I used two 1G in parallel to handle the high current if both thrusters are used together, this was easier and cheaper since I purchased a length of 1G wire and packages of 1G lugs. A Cat5 cable connects the shunt electronics to the display. The small red wire is the +12V sense/power connection for the Victron monitor.
I changed the ground bus bar to a Blue Sea 8 position 600A bus bar. The original was a 250A 4 position bar. All grounds are connected to this. The two 1G jumpers from the shunt are also connected to this. The original bus bar had 5/16" posts, the new has 3/8". I had to reterminate the existing cables to fit on the larger posts. Some of the ground connections that were directly on the batteries would not reach the bus bar (rear thruster ground and safety ground for the inverter). I added a heavy duty Blue Sea power post in the battery compartment for these and connected a short 1G jumper to the ground bus bar. The original ground bus bar was relocated to a different location in the genset compartment, I used this for all of the green bonding wire grounds. A 6G jumper connects this to the new ground bus bar.
The battery switch above the bar is for the genset. I added this to allow a complete disconnect of the genset power as a safety measure. I also added an ANL fuse to the genset power connection. The fuse holder is in the battery compartment next to the house +12V bus bar.
The Victron BMV600S battery monitor display installed below the Genset control panel. I also installed a LED next to the display to monitor the ACR state. (not visible in this picture)
Since I now have two battery banks I removed one of the ACRs, it is no longer needed and has become a spare. I also discovered that the ACRs are not connected properly by Ranger, they feed +12V directly to the remote LED connection, this is not needed or even recomended by Blue Sea. The minimum connection for the ACR to function is the two batteries and a ground. The additional connections are for a remote status LED and start lockout. I rewired mine and ran a cable forward to have a remote status LED visible from the helm. The start lockout is not used.
I am pleased with this modification, it is working very well. I programmed the Victron for a bank capacity 270AH so it can provide state of charge as a percentage. It takes Peukert's Law into account to improve accuracy for very high or low currents (Available battery capacity is reduced for high currents and increased for low currents, the nominal point is a 20 hour discharge rate). The thrusters actually work better, if both are used together (although I rarely do this) they have more power than before. With both thrusters active the house bank voltage is still well over 12V, the Victron indicates about a 300A drain. The engine alternator is helping to provide current so the actual current to the thrusters is higher. I also learned that the alternator is capable of very impressive current at idle, after engine start I can see 100A or more initial charge current. This is more than I expected at idle and was a pleasant surprise.
I have some additional changes planned. I will add a relay to disable the ACR when AC power is applied to the battery charger. The ProMariner has independant multi stage charge control for up to three battery banks, the ACR ties the banks together and eliminates this advantage.
I also need to increase battery charge capacity, the ProMariner is only 20A. It takes hours to replace even a moderate discharge on the house bank. I will install a seperate high capacity charger (probably 40 to 60A range) to use with the genset to more quickly replace AH used while on a mooring or on the hook.
I can also easily determine the current drawn by various items on the boat. For example, the inverter idling (powered on but no load) draws about 1.5A.
It is interesting to note that the deep cycle batteries are actually capable of very high current. There are some that believe an engine start battery is needed for thrusters, however Imtra-Sidepower does not specify a battery type. They only specify a minimum CCA rating, for the SE30 this is 200 CCA. The Centennial group 27 deep cycle batteries are rated 700 CCA, the start battery is rated at 800 CCA- not that much different!
Howard
As an Electrical Engineer it bothered me that an additional 90AH capacity was sitting unused most of the time, except for a number of seconds of thruster use and a few minutes of windlass use. I researched this and learned that modern thinking is to combine separate banks (except for the engine start battery) into a single large bank when possible. Nigel Calder is an advocate of this, as are many ABYC certified marine electricians. An exception would be for very large bow thrusters which require a large battery bank located next to the thruster, in many cases this would also be 24V. In our case we have a small thruster with a nominal current draw of 195A per Imtra specification, which allows the thruster battery to be remote and connected via 1G cable. In a multi battery bank is is also important to balance the current in/out of the batteries for best lifetime and efficiency. There are several methods to do this, I chose to use individual cables to each battery rather than "daisy chaining" them. This allowed me to use 1G cable everywhere and still handle the current used by the thrusters with minimal voltage drop or cable heating.
I also wanted to install a smart battery monitor that would provide a more accurate "gas gauge" than a simple volt meter. I selected the Victron BMV600S which can monitor up to 500A and provides data on AH consumed, battery state of charge as a percentage, voltage, and much more. It has audible and visual alarms that can be set to specified discharge level and/or voltage. It includes a 500A shunt which monitors current in/out of the monitored bank so it can compute AH in and out.
The battery charger (ProMariner ProNautic 1220P) is a smart multi bank charger that has a remote temperature probe to compensate the voltages used during the various charge phases, but the cable length only allowed this to reach the engine start battery. This battery typically requires the least amount of charging. It would be better to monitor the temperature of a house battery. In practice this is probably a minor point, the batteries probably stay at nearly identical temperatures unless the house bank is used at high discharge or charge rates. The Automatic Charge Relay negates the multi bank feature of the charger, more on this later.
After this research I decided to combine the house and thruster banks to have a single 270AH bank for the house, thrusters, windlass, etc.- everything except engine start. This required reconfiguration of the battery connections, installation of larger bus bars, and connection of the Victron battery monitor. To allow the battery charger temp sense probe to be on a house battery I moved the engine start battery to a different location in the battery compartment. I had to move the engine fuse forward a bit to allow the cables to reach the new position.
I needed to make heavy duty cables, using mostly 1G marine grade Red and Yellow battery cable. More research pointed me to the right direction on this and I found an excellent tutorial on crimping battery lugs. The proper crimp tool costs more than a cheap Ancor hammer crimper but does a significantly better job. I also learned there are different grades of battery cable lugs, I chose to use heavy duty lugs, not the typical Ancor lugs that you see everywere. See http://www.pbase.com/mainecruising/battery_cables for a great tutorial.
FTZ Heavy Duty lug crimp tool that I used. The handles are about 2 feet long to allow easy crimping. The rotating dies allow crimping lugs for wire sizes 6G to 4/0G. It makes a diamond shaped crimp and actually reduces the diameter of the lug to compress against the wire. A tip that I learned is to repeat each crimp after rotating the lug 90 degrees. This smooths a sharp edge left on two of the points left by the crimp tool.
FTZ Heavy Duty lugs, these are very thick walled, tin plated copper. When crimped properly the battery cable cold forms to the lug for an air tight connection. I obtained these from Fisheries Supply. The lugs are labled and have a color code that matches a table on the crimp tool so you can select the proper dies.
Example of a completed battery cable end. The heavy duty adhesive lined heat shrink tubing seals the lug and the end of the cable. I used a Brother P-touch to make the labels and protected this with clear heat shrink. The battery lug and cable has a lot of mass and is slow to heat. I found that I got the best adhesive melting on the lug side by pre-heating the lug before sliding the tubing over it and then shrinking. You want to see some the adhesive melting and flowing slightly out the ends of the tubing. I found that Gregs Marine Wire Supply is a good source for quality marine wire, http://gregsmarinewiresupply.com/Zen/.
All of the house/thruster +12V connections are on a 600A 4 position Blue Sea bus bar. Connections are the alternator, one side of the Automatic Charge Relay, Genset, Thruster feed to switch, House feed to switch, Inverter, 3 batteries, and +12V to the Victron circuit board on the shunt. To balance the current between the three batteries I used a seperate 1G jumper for each one. A Blue Sea protective cover prevents accidental shorting to the +12V.
House/Thruster 600A 4 position +12V battery bus bar
The Victron 500A shunt is mounted to a piece of starboard. The starboard is bonded to the hull in the battery compartment. One side has 3 1G cables to the batteries (to keep the current balanced), the other has a pair of 1G jumpers to the ground bus bar. I used two 1G in parallel to handle the high current if both thrusters are used together, this was easier and cheaper since I purchased a length of 1G wire and packages of 1G lugs. A Cat5 cable connects the shunt electronics to the display. The small red wire is the +12V sense/power connection for the Victron monitor.
I changed the ground bus bar to a Blue Sea 8 position 600A bus bar. The original was a 250A 4 position bar. All grounds are connected to this. The two 1G jumpers from the shunt are also connected to this. The original bus bar had 5/16" posts, the new has 3/8". I had to reterminate the existing cables to fit on the larger posts. Some of the ground connections that were directly on the batteries would not reach the bus bar (rear thruster ground and safety ground for the inverter). I added a heavy duty Blue Sea power post in the battery compartment for these and connected a short 1G jumper to the ground bus bar. The original ground bus bar was relocated to a different location in the genset compartment, I used this for all of the green bonding wire grounds. A 6G jumper connects this to the new ground bus bar.
The battery switch above the bar is for the genset. I added this to allow a complete disconnect of the genset power as a safety measure. I also added an ANL fuse to the genset power connection. The fuse holder is in the battery compartment next to the house +12V bus bar.
The Victron BMV600S battery monitor display installed below the Genset control panel. I also installed a LED next to the display to monitor the ACR state. (not visible in this picture)
Since I now have two battery banks I removed one of the ACRs, it is no longer needed and has become a spare. I also discovered that the ACRs are not connected properly by Ranger, they feed +12V directly to the remote LED connection, this is not needed or even recomended by Blue Sea. The minimum connection for the ACR to function is the two batteries and a ground. The additional connections are for a remote status LED and start lockout. I rewired mine and ran a cable forward to have a remote status LED visible from the helm. The start lockout is not used.
I am pleased with this modification, it is working very well. I programmed the Victron for a bank capacity 270AH so it can provide state of charge as a percentage. It takes Peukert's Law into account to improve accuracy for very high or low currents (Available battery capacity is reduced for high currents and increased for low currents, the nominal point is a 20 hour discharge rate). The thrusters actually work better, if both are used together (although I rarely do this) they have more power than before. With both thrusters active the house bank voltage is still well over 12V, the Victron indicates about a 300A drain. The engine alternator is helping to provide current so the actual current to the thrusters is higher. I also learned that the alternator is capable of very impressive current at idle, after engine start I can see 100A or more initial charge current. This is more than I expected at idle and was a pleasant surprise.
I have some additional changes planned. I will add a relay to disable the ACR when AC power is applied to the battery charger. The ProMariner has independant multi stage charge control for up to three battery banks, the ACR ties the banks together and eliminates this advantage.
I also need to increase battery charge capacity, the ProMariner is only 20A. It takes hours to replace even a moderate discharge on the house bank. I will install a seperate high capacity charger (probably 40 to 60A range) to use with the genset to more quickly replace AH used while on a mooring or on the hook.
I can also easily determine the current drawn by various items on the boat. For example, the inverter idling (powered on but no load) draws about 1.5A.
It is interesting to note that the deep cycle batteries are actually capable of very high current. There are some that believe an engine start battery is needed for thrusters, however Imtra-Sidepower does not specify a battery type. They only specify a minimum CCA rating, for the SE30 this is 200 CCA. The Centennial group 27 deep cycle batteries are rated 700 CCA, the start battery is rated at 800 CCA- not that much different!
Howard
