JDCAVE
Guru
- Joined
- Apr 3, 2011
- Messages
- 2,907
- Location
- Canada
- Vessel Name
- Phoenix Hunter
- Vessel Make
- Kadey Krogen 42 (1985)
I will need to replace my 10 year old house and starter banks prior to the boating season this year. In an earlier post (Electrical Systems 101) I received a lot of good information and cautions from people and as per advice, I have read through Calder's book on the subject. Being a bit dense, I have read and re-read the battery and electrical systems several times and I think I have a much better feel for electrical systems and stuff I have done wrong!
My house bank consists of 10 Trojan 105's wired as a 12 volt system. The starter bank consists of 2 Trojan 105's, also wired as a 12 volt system. I am thinking of replacing the starter batteries with two D31's. I haven't yet made up my mind if I stay with the T-105's or to a cheaper 6 volt deep cycle alternative.
The alternator is a Amptech S125E. I tested it yesterday and it is putting out at 14.5 volts when charging. I have a Balmar Max Charge MC612 multi-stage marine regulator which charges the house bank. The starter bank charging process is regulated with the Balmar Digital Duo Charge, which puts out a DC-DC charge, i.e. the starter bank is charged from the house bank when voltages on the house bank exceed 13 volts, and provides up to 30 amps charging. Below 13V, the Max Charge is in sleep mode.
As per Calder's recommendation, I have determined the power consumption of the following electrical loads and the estimated daily power requirements of each. I did this by going off grid and shutting off the charger and turning on the individual loads one by one and monitoring the amperage of these load from the Heart Interface Link 2000 monitor. I presume that the "Background" power draw includes loads from monitor itself as well as various background LEDs about the boat....
The background draw is calculated first. This must subtracted off in order to calculate each load uniquely, otherwise these loads would be overestimated.
A couple of things jump right out. The fridge and freezer are real pigs on power. I still have to make these more efficient (venting the warm air from under the watch berth, where these units are situated). I also have something called a "Circumvent" which I have left on all the time. The PO installed this to replace the air in the bilge in order to control humidity on the boat and condensation in the bilge, but it seems that I should review whether this needs to be on all the time. It might be more important in the winter.
So I'm looking at the total requirement of 187 amp-hours and estimate that I need about a 1250 amp-hour bank for two days of use. This assumes the bank is cycled from 80% SOC to 50% SOC. The current bank is 1,125 amp-hours. If I stay with the current size of bank, it would be prudent to fire up the generator after 36 hour or so.
Note that I have not yet estimated the consumption of the Webasto Hydronic system. This would be additive to requirements in cold weather. Also I need to follow up on how the Thruster bank is charged. The Thruster unit is a Wesmar 24VDC with a Victron Centaur 12-40 charger. The thruster batteries are AGM. I am not sure how charging of these is regulated when the alternator is charging the other banks.
Comments?
Jim
My house bank consists of 10 Trojan 105's wired as a 12 volt system. The starter bank consists of 2 Trojan 105's, also wired as a 12 volt system. I am thinking of replacing the starter batteries with two D31's. I haven't yet made up my mind if I stay with the T-105's or to a cheaper 6 volt deep cycle alternative.
The alternator is a Amptech S125E. I tested it yesterday and it is putting out at 14.5 volts when charging. I have a Balmar Max Charge MC612 multi-stage marine regulator which charges the house bank. The starter bank charging process is regulated with the Balmar Digital Duo Charge, which puts out a DC-DC charge, i.e. the starter bank is charged from the house bank when voltages on the house bank exceed 13 volts, and provides up to 30 amps charging. Below 13V, the Max Charge is in sleep mode.
As per Calder's recommendation, I have determined the power consumption of the following electrical loads and the estimated daily power requirements of each. I did this by going off grid and shutting off the charger and turning on the individual loads one by one and monitoring the amperage of these load from the Heart Interface Link 2000 monitor. I presume that the "Background" power draw includes loads from monitor itself as well as various background LEDs about the boat....
The background draw is calculated first. This must subtracted off in order to calculate each load uniquely, otherwise these loads would be overestimated.
A couple of things jump right out. The fridge and freezer are real pigs on power. I still have to make these more efficient (venting the warm air from under the watch berth, where these units are situated). I also have something called a "Circumvent" which I have left on all the time. The PO installed this to replace the air in the bilge in order to control humidity on the boat and condensation in the bilge, but it seems that I should review whether this needs to be on all the time. It might be more important in the winter.
So I'm looking at the total requirement of 187 amp-hours and estimate that I need about a 1250 amp-hour bank for two days of use. This assumes the bank is cycled from 80% SOC to 50% SOC. The current bank is 1,125 amp-hours. If I stay with the current size of bank, it would be prudent to fire up the generator after 36 hour or so.
Note that I have not yet estimated the consumption of the Webasto Hydronic system. This would be additive to requirements in cold weather. Also I need to follow up on how the Thruster bank is charged. The Thruster unit is a Wesmar 24VDC with a Victron Centaur 12-40 charger. The thruster batteries are AGM. I am not sure how charging of these is regulated when the alternator is charging the other banks.
Comments?
Jim
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