Power Consumption Question.
- Thread starter Bad Obsession
- Start date
- Status
gps voltage reading
Rob The short answer is not very. Most people have multipe connections between the battery bank and gps power line which inherently have some loss, not to mention the cable runs themselves. Consequently, the gps will measure votage at it's input somewhat lower than the bank. To get a meaninful reading from your gps, simply compare the bank voltage with that read from the gps and you can subsequently use that difference to extrapolate actual battery condition from the gps.
Rob The short answer is not very. Most people have multipe connections between the battery bank and gps power line which inherently have some loss, not to mention the cable runs themselves. Consequently, the gps will measure votage at it's input somewhat lower than the bank. To get a meaninful reading from your gps, simply compare the bank voltage with that read from the gps and you can subsequently use that difference to extrapolate actual battery condition from the gps.
How many amp hours do you get out of a Group 27?
How many amp hours can you get out of a Group 27 battery? I have never seen any documentation that states how many amps a full battery holds. Then again, I am not that familiar with electrical applications. I know that the DC system is a 12 volt system but my knowledge doesn't go that much further than that. I can safely wire things up and I know how the fuses work. I guess the best system is to have a battery monitor and when the battery starts to show enough drain it is time to use the engine to charge the system.
How many amp hours can you get out of a Group 27 battery? I have never seen any documentation that states how many amps a full battery holds. Then again, I am not that familiar with electrical applications. I know that the DC system is a 12 volt system but my knowledge doesn't go that much further than that. I can safely wire things up and I know how the fuses work. I guess the best system is to have a battery monitor and when the battery starts to show enough drain it is time to use the engine to charge the system.
battery rating - generalized
Some common battery size codes used are: (ratings are approximate) U1 34 to 40 Amp hours 12 volts Group 24 70-85 Amp hours 12 volts Group 27 85-105 Amp hours 12 volts Group 31 95-125 Amp hours 12 volts 4-D 180-215 Amp hours 12 volts 8-D 225-255 Amp hours 12 volts Golf cart & T-105 180 to 220 Amp hours 6 volts L-16 340 to 415 Amp hours 6 volts
Some common battery size codes used are: (ratings are approximate) U1 34 to 40 Amp hours 12 volts Group 24 70-85 Amp hours 12 volts Group 27 85-105 Amp hours 12 volts Group 31 95-125 Amp hours 12 volts 4-D 180-215 Amp hours 12 volts 8-D 225-255 Amp hours 12 volts Golf cart & T-105 180 to 220 Amp hours 6 volts L-16 340 to 415 Amp hours 6 volts
West Marine Advisors, again
Go here: http://www.westmarine.com/webapp/wcs/stores/servlet/westadvisor/10001/-1/10001/Batteries-DeepCycle.htm Bad O, ya know, there's a lot to learn there. Go to www.westmarine.com, and put your pointer on "Product Advice" on the top banner. It'll come up with "West Advisors". Teach a man to fish...
Go here: http://www.westmarine.com/webapp/wcs/stores/servlet/westadvisor/10001/-1/10001/Batteries-DeepCycle.htm Bad O, ya know, there's a lot to learn there. Go to www.westmarine.com, and put your pointer on "Product Advice" on the top banner. It'll come up with "West Advisors". Teach a man to fish...
Thanks guys.....another question now.
Most of the electronics on my boat have been on there for a while and I don't have owner manuals for them. I am not sure what the draw is for these things. How do I figure out what each piece of equipment uses or is there a safe average? Navigation lights, bow and stern? GPS? Autohelm Raymarine S1 wheelpilot? (I know that it draws about .5 in standby but not what it draws when it is in use). Car Stereo?
Most of the electronics on my boat have been on there for a while and I don't have owner manuals for them. I am not sure what the draw is for these things. How do I figure out what each piece of equipment uses or is there a safe average? Navigation lights, bow and stern? GPS? Autohelm Raymarine S1 wheelpilot? (I know that it draws about .5 in standby but not what it draws when it is in use). Car Stereo?
Power usage
Most of your lights are probably use a 10 watt bulb. All the electronics should have a wattage usage on the tag on them. Your GPS doesn't draw much, unless it has a depth finder in it, then usage would go up. Not sure about the S1 autopilot, but would guess it should be under 5 amps tops, when in use and actually turning the wheel. The internet should provide answers if you don't find the wattage of each unit on the tag.
Most of your lights are probably use a 10 watt bulb. All the electronics should have a wattage usage on the tag on them. Your GPS doesn't draw much, unless it has a depth finder in it, then usage would go up. Not sure about the S1 autopilot, but would guess it should be under 5 amps tops, when in use and actually turning the wheel. The internet should provide answers if you don't find the wattage of each unit on the tag.
Rob..
Quote: "***My question is how reliable is the voltage feature is on a GPS?***" In my experience IT'S NOT accurate at all! I have two Garmin plotters a GPS Map-176 and a 182C. Both can be connected at my helm and they both read about .3 - .5 volts apart! My Xantrex XBM lines up perfectly with both my Fluke and my UEI multi-meters.. Use the GPS as a very rough guide only... The BEST money you can spend on a 12V system is a Xantrex Link 10 or XBM battery monitor...
Quote: "***My question is how reliable is the voltage feature is on a GPS?***" In my experience IT'S NOT accurate at all! I have two Garmin plotters a GPS Map-176 and a 182C. Both can be connected at my helm and they both read about .3 - .5 volts apart! My Xantrex XBM lines up perfectly with both my Fluke and my UEI multi-meters.. Use the GPS as a very rough guide only... The BEST money you can spend on a 12V system is a Xantrex Link 10 or XBM battery monitor...
Bad..
Quote: "Most of the electronics on my boat have been on there for a while and I don't have owner manuals for them. I am not sure what the draw is for these things. How do I figure out what each piece of equipment uses or is there a safe average?" I know this has been said before but a Xantrex Link 10 or Xantrex XBM is the best way to monitor consumption, current draw or state of charge. It can measure any item or a group of items. In general these things are a fuel gauge for your battery bank!! It is one of the best pieces of equipment I have ever purchased for the boat. Fry or drastically shorten the life of one bank, by NOT using one, and it will have paid for itself! http://www.xantrex.com/web/id/96/p/1/pt/7/product.asp You can also measure these items individually with a multi meter that can measure DC amps but there is no way for it to keep a running tally on amp hours consumed like a true battery monitor can. This is especially tough to figure out on variable draw devices like a VHF, stereo or auto-pilot. A battery monitor will measure total ah's consumed and give you a nice read out of it. As you charge the battery it tells you how many amps your restoring and how far away from 100% of charge you are..
Quote: "Most of the electronics on my boat have been on there for a while and I don't have owner manuals for them. I am not sure what the draw is for these things. How do I figure out what each piece of equipment uses or is there a safe average?" I know this has been said before but a Xantrex Link 10 or Xantrex XBM is the best way to monitor consumption, current draw or state of charge. It can measure any item or a group of items. In general these things are a fuel gauge for your battery bank!! It is one of the best pieces of equipment I have ever purchased for the boat. Fry or drastically shorten the life of one bank, by NOT using one, and it will have paid for itself! http://www.xantrex.com/web/id/96/p/1/pt/7/product.asp You can also measure these items individually with a multi meter that can measure DC amps but there is no way for it to keep a running tally on amp hours consumed like a true battery monitor can. This is especially tough to figure out on variable draw devices like a VHF, stereo or auto-pilot. A battery monitor will measure total ah's consumed and give you a nice read out of it. As you charge the battery it tells you how many amps your restoring and how far away from 100% of charge you are..
Thanks Mainesail and Don
Thanks for the input. I love the Link 20 advise, but hate the price. Another question, can I buy a Link 10 single bank moniter and put in a A-B switch to lower the cost? Rob
Thanks for the input. I love the Link 20 advise, but hate the price. Another question, can I buy a Link 10 single bank moniter and put in a A-B switch to lower the cost? Rob
Thanks Guys
This has been a very informative and interesting post. It is nice to have such a depth in knowledge to draw from. The battery monitor is a great idea and it takes a lot of the guess work out of the system. I never realized how much though goes into the whole battery issue. Now that I have heard a lot of this advice, I really wish that Catalina had made a larger battery storage area. How could I go about putting the two group 27s in a series for the house battery and adding the third starting battery to a different area? What would I need to buy and would I need to change my battery selector switch? I definately have room in the area under my quarter berth but I am a little nervous about putting a battery in the same genereal area as the fuel tank. I will have to think on that one.
This has been a very informative and interesting post. It is nice to have such a depth in knowledge to draw from. The battery monitor is a great idea and it takes a lot of the guess work out of the system. I never realized how much though goes into the whole battery issue. Now that I have heard a lot of this advice, I really wish that Catalina had made a larger battery storage area. How could I go about putting the two group 27s in a series for the house battery and adding the third starting battery to a different area? What would I need to buy and would I need to change my battery selector switch? I definately have room in the area under my quarter berth but I am a little nervous about putting a battery in the same genereal area as the fuel tank. I will have to think on that one.
There...
Rob, There really is NO need for monitoring a start bank! Each start will draw less than about 1.5 total amp hours that's it. The amps consumed are then very, very easily replaced in a relatively short time. Why waste the money to monitor this kind of use if in fact you ever even physicall use your starting bank at all? I've argued for years that a start battery should be called an "emergency" battery. I NEVER use my start bank to start my boat and always use my house bank. My start battery is charged via a charging relay so I know it's always topped up. About once every month or so I vacuum my boat using the inverter and my start battery to "exercise" it and give it a little draw. Once I'm done "exercising" my start/emergency battery I switch right back to my house bank where it stays and my solar panel top my start bank back up! A link 10 or XBM connected to the house bank is all you need! Unless of course you have money to throw out the window on a Link 20...
Rob, There really is NO need for monitoring a start bank! Each start will draw less than about 1.5 total amp hours that's it. The amps consumed are then very, very easily replaced in a relatively short time. Why waste the money to monitor this kind of use if in fact you ever even physicall use your starting bank at all? I've argued for years that a start battery should be called an "emergency" battery. I NEVER use my start bank to start my boat and always use my house bank. My start battery is charged via a charging relay so I know it's always topped up. About once every month or so I vacuum my boat using the inverter and my start battery to "exercise" it and give it a little draw. Once I'm done "exercising" my start/emergency battery I switch right back to my house bank where it stays and my solar panel top my start bank back up! A link 10 or XBM connected to the house bank is all you need! Unless of course you have money to throw out the window on a Link 20...
Mainesail
Mainesail- I do not have a starting battery. I have a manual start outboard that just yesterday I bought the charging kit to be installed this spring. I have two group 27's that when I rewired my boat last spring I split up the various 12v items I have onboard. Radio/cd, Sirius Tuner, auto-pilot, GPS, Depth/speed log meter, Wind Instruments, lights (nav, anchor,steaming/deck light), fans, 12v power points, compass, bilge pumps, wash down pump, and faucet. These are the 12v items that I have on my boat. I use a portable inverter for the DVD player and laptop. I like and use these gadgets frequently. I have gotten used to using the autopilot alot. I believe that this is my largest consumer of electricity. I have never run down my batteries while sailing around on my lake, but I trailer to Lake Michigan and Superior for a week at a time and have had problems. I have always carried a 1000k generater to put some life back into them. This year with the charging system and a solar panel I want to get away from hauling the generater. When putting the 12v power points on each battery my goal was to have a known state of charge. I'm not sure if I care about some of the other features the Link's have to offer. I am doing a little research on them as we speak. I know a cheap voltmeter will offer me the knowledge that I am seeking, but my battery location is not user friendly. I like the abililty to get an accurate read out with a push of a button. Thanks for your time. Regards- Rob Hessenius
Mainesail- I do not have a starting battery. I have a manual start outboard that just yesterday I bought the charging kit to be installed this spring. I have two group 27's that when I rewired my boat last spring I split up the various 12v items I have onboard. Radio/cd, Sirius Tuner, auto-pilot, GPS, Depth/speed log meter, Wind Instruments, lights (nav, anchor,steaming/deck light), fans, 12v power points, compass, bilge pumps, wash down pump, and faucet. These are the 12v items that I have on my boat. I use a portable inverter for the DVD player and laptop. I like and use these gadgets frequently. I have gotten used to using the autopilot alot. I believe that this is my largest consumer of electricity. I have never run down my batteries while sailing around on my lake, but I trailer to Lake Michigan and Superior for a week at a time and have had problems. I have always carried a 1000k generater to put some life back into them. This year with the charging system and a solar panel I want to get away from hauling the generater. When putting the 12v power points on each battery my goal was to have a known state of charge. I'm not sure if I care about some of the other features the Link's have to offer. I am doing a little research on them as we speak. I know a cheap voltmeter will offer me the knowledge that I am seeking, but my battery location is not user friendly. I like the abililty to get an accurate read out with a push of a button. Thanks for your time. Regards- Rob Hessenius
You wouldn't want..
Bad, Quote: "How could I go about putting the two group 27s in a series for the house battery and adding the third starting battery to a different area? What would I need to buy and would I need to change my battery selector switch?" First, unless you have a 24 volt system DO NOT wire two 12v batteries in series. You'll want to wire them in parallel. What do you need: 1) A short pair of "jumper wires" one black (negative) and one red (positive) to create your parallel house bank. You'll want 1/0 or 2/0 tinned marine grade wire for this. At a minimum you'll need 1 AWG. 1/0 is larger than 1 AWG and 2/0 is larger than 1/0... 2) You'll need a length of battery cable to go from the #2 position (unless you decide #2 is your house bank) on your battery switch to the new start battery and one negative cable to reach your negative buss location. 3) You'll need a new start battery at the least and possibly two new house bank batteries. 4) You'll need battery boxes and tie downs 5) While not 100% necessary, although it is now an ABYC requirement for new boats, ALL boats SHOULD have a LARGE fuse at the positive battery post or within 12" of each bank! If a battery cable shorted and there was no fuse at the battery it could mean disaster...!! ANL style fuse blocks work great! ANL Fuse Block Link: http://www.defender.com/product.jsp?path=-1|328|296553|823931&id=823876 If you plan on making cables your self you'll need adhesive lined heat shrink, battery lugs to fit the size wire you have, a heat gun to melt the adhesive line heat shrink and a battery lug crimper such as the one made by Anchor and sold at West Marine. Crimper: http://www.defender.com/product.jsp?path=-1|328|49758|319689&id=127477
Bad, Quote: "How could I go about putting the two group 27s in a series for the house battery and adding the third starting battery to a different area? What would I need to buy and would I need to change my battery selector switch?" First, unless you have a 24 volt system DO NOT wire two 12v batteries in series. You'll want to wire them in parallel. What do you need: 1) A short pair of "jumper wires" one black (negative) and one red (positive) to create your parallel house bank. You'll want 1/0 or 2/0 tinned marine grade wire for this. At a minimum you'll need 1 AWG. 1/0 is larger than 1 AWG and 2/0 is larger than 1/0... 2) You'll need a length of battery cable to go from the #2 position (unless you decide #2 is your house bank) on your battery switch to the new start battery and one negative cable to reach your negative buss location. 3) You'll need a new start battery at the least and possibly two new house bank batteries. 4) You'll need battery boxes and tie downs 5) While not 100% necessary, although it is now an ABYC requirement for new boats, ALL boats SHOULD have a LARGE fuse at the positive battery post or within 12" of each bank! If a battery cable shorted and there was no fuse at the battery it could mean disaster...!! ANL style fuse blocks work great! ANL Fuse Block Link: http://www.defender.com/product.jsp?path=-1|328|296553|823931&id=823876 If you plan on making cables your self you'll need adhesive lined heat shrink, battery lugs to fit the size wire you have, a heat gun to melt the adhesive line heat shrink and a battery lug crimper such as the one made by Anchor and sold at West Marine. Crimper: http://www.defender.com/product.jsp?path=-1|328|49758|319689&id=127477
Rod
You might want to go a simpler but almost as informative route which would allow you to monitor voltage on either battery and not do any rewiring. The option would be to purchase an analog DC voltmeter you can mount anywhere convenient with a simple switch to each battery such that switching will allow you to see the voltage on either battery. The switch need not be anything heavy duty as no large current would be present and an analog meter goes for $15 or so. Not as elegant or expensive as the Link10 but should serve your stated purpose fine.
You might want to go a simpler but almost as informative route which would allow you to monitor voltage on either battery and not do any rewiring. The option would be to purchase an analog DC voltmeter you can mount anywhere convenient with a simple switch to each battery such that switching will allow you to see the voltage on either battery. The switch need not be anything heavy duty as no large current would be present and an analog meter goes for $15 or so. Not as elegant or expensive as the Link10 but should serve your stated purpose fine.
If Your Batteries are Isolated...
...via a 1,2,Both Switch, then you shouldn't have a problem. Just switch the good one out of the loop to eliminate it from the battery draw. Or, you could always charge your batteries part way through your trip by running the engine in "charge" mode (Run it in nuetral at a higher RPM) while you sail. Look the the usage labels on your GPS, Running Light Bulbs and Autohelm to calculate how long you can use then versus the amp-hours of the house battery. P.S. Carry the jumper "just in case". I usually keep mine on board during the summer and move it to the car in the winter. Although, I have never had to use it to start the boat (knock wood) or the car.
...via a 1,2,Both Switch, then you shouldn't have a problem. Just switch the good one out of the loop to eliminate it from the battery draw. Or, you could always charge your batteries part way through your trip by running the engine in "charge" mode (Run it in nuetral at a higher RPM) while you sail. Look the the usage labels on your GPS, Running Light Bulbs and Autohelm to calculate how long you can use then versus the amp-hours of the house battery. P.S. Carry the jumper "just in case". I usually keep mine on board during the summer and move it to the car in the winter. Although, I have never had to use it to start the boat (knock wood) or the car.
MaineSail
I agree -= was only providing another option which might work given the simplicity of his system and it's draw. Even an analog meter can provide some useful info when used properly. Unless I'm mistaken, if he used the Link et al on the wiring described and routinely switched batteries (i.e., banks), the battery history info would be lost making some of the info these shunt-fed meters provide meaningless. Nevertheless, I have the Xantrex version of the system monitor and a redundant metering system specifically for the inverter draw, either of which would be preferable to the analog setup which only goes to show there are "hundreds" of variations of the theme.
I agree -= was only providing another option which might work given the simplicity of his system and it's draw. Even an analog meter can provide some useful info when used properly. Unless I'm mistaken, if he used the Link et al on the wiring described and routinely switched batteries (i.e., banks), the battery history info would be lost making some of the info these shunt-fed meters provide meaningless. Nevertheless, I have the Xantrex version of the system monitor and a redundant metering system specifically for the inverter draw, either of which would be preferable to the analog setup which only goes to show there are "hundreds" of variations of the theme.
Battery switch
Blue Sea systems makes the best battery switch http://bluesea.com/products/5511e You won't accidentally conbined two batteries to drain the good one. Add a Balmar digital dual charge, there's nothing to remember. http://www.balmar.net/page20-Duocharge.html When on shore power I disconnect the house bank from the charger (another switch) and use a 120AC to 12V power supply. The shore power charger will kill your house bank battery if you use enough DC power. The charger senses current draw and will raise the voltage. The battery just cook. Solar panel and LED are great improvements.
Blue Sea systems makes the best battery switch http://bluesea.com/products/5511e You won't accidentally conbined two batteries to drain the good one. Add a Balmar digital dual charge, there's nothing to remember. http://www.balmar.net/page20-Duocharge.html When on shore power I disconnect the house bank from the charger (another switch) and use a 120AC to 12V power supply. The shore power charger will kill your house bank battery if you use enough DC power. The charger senses current draw and will raise the voltage. The battery just cook. Solar panel and LED are great improvements.
Thanks
Guys- My batteries are isolated from each other. I replaced the (off-1-2-both) battery switch with two (on/off) Blue Seas battery switches. I added a Blue Seas ANL fuse block to each battery. I also fused everything other than the lights(used the existing DC AGC/glass switch panel) with a BS ATC fuse block. The guy who helped me rewire my boat is a certified aviation electrician. His wiring is gorgeous, perfect. The boat was wired to ABYC requirements. I did some serious studing yesterday and realized that the way I wanted to use the Link 10 would not work. The Link 20 is a beautiful piece of equipment, but a little more $ than I want to spend at this time. The analog voltmeter way, was what I thought I would eliminate by using the GPS and its separate power points. Thanks Rob
Guys- My batteries are isolated from each other. I replaced the (off-1-2-both) battery switch with two (on/off) Blue Seas battery switches. I added a Blue Seas ANL fuse block to each battery. I also fused everything other than the lights(used the existing DC AGC/glass switch panel) with a BS ATC fuse block. The guy who helped me rewire my boat is a certified aviation electrician. His wiring is gorgeous, perfect. The boat was wired to ABYC requirements. I did some serious studing yesterday and realized that the way I wanted to use the Link 10 would not work. The Link 20 is a beautiful piece of equipment, but a little more $ than I want to spend at this time. The analog voltmeter way, was what I thought I would eliminate by using the GPS and its separate power points. Thanks Rob
The reason for large, not divided, house banks
IS IT BETTER TO HAVE ONE OR TWO BATTERY BANKS FOR HOUSE USE? (By Nigel Calder - I DIDN’T write this!!!) The popular arrangement of having two house banks alternated in use needs scrutiny before I go any further. LIFE CYCLES: As we have seen, the life expectancy of a battery in cycling service is directly related to the depth to which it is discharged at each cycle - the greater the depth of discharge, the shorter the battery’s life. This relationship between depth of discharge and battery life is NOT linear. As the depth of discharge increases, a battery’s life expectancy is disproportionately shortened. A given battery may cycle through 10% of its capacity 2,000 times, 50% of its capacity 300 times and 100% of its capacity around 100 times. Let’s say, for arguments sake, that a boat has two 200-ah battery banks, alternated from day to day, with a daily load of 80 Ah. Each bank will be discharged by 40% (80 Ah of one of the two 200 Ah banks) of its capacity before being recharged. The batteries will fail after 380 cycles, which is 760 days (since each is used every other day). If the two banks had been wired in parallel, to make a single 400 Ah battery bank, this bank would have been discharged by 20% of capacity every day, with a life expectancy of 800 days, a 5% increase in life expectancy using exactly the same batteries! But now let’s double the capacity of the batteries, so that the boat has either two 400 Ah banks, or a single 800 Ah bank, but with the same 80 Ah daily load. The two separate banks will be cycling through 20% of capacity every other day, resulting in a total life expectancy of 1,600 days. Doubling the size of the battery banks in relation to the load has produced a 210% increase in life expectancy. The single 800 Ah bank will be cycling through 10% of capacity every day, resulting in a life expectancy of 2,000 days - a 25% increase in life expectancy over the two (400 Ah) banks, and a 250% increase in life expectancy over the single 400 Ah battery bank! There are two immediate conclusions to be drawn from these figures: 1. For a given total battery capacity, wiring the (house) batteries into a single high capacity bank, rather than having them divided into two alternating banks, will result in a longer overall life expectancy for the batteries. 2. All other things being equal, any increase in the overall capacity of a battery bank will produce a disproportionate increase in its life expectancy (through reducing the depth of discharge at each cycle). FOR BATTERY LONGEVITY, A SINGLE LARGE (HOUSE) BANK, THE LARGER THE BETTER, IS PREFERABLE TO DIVIDED (HOUSE) BANKS.
IS IT BETTER TO HAVE ONE OR TWO BATTERY BANKS FOR HOUSE USE? (By Nigel Calder - I DIDN’T write this!!!) The popular arrangement of having two house banks alternated in use needs scrutiny before I go any further. LIFE CYCLES: As we have seen, the life expectancy of a battery in cycling service is directly related to the depth to which it is discharged at each cycle - the greater the depth of discharge, the shorter the battery’s life. This relationship between depth of discharge and battery life is NOT linear. As the depth of discharge increases, a battery’s life expectancy is disproportionately shortened. A given battery may cycle through 10% of its capacity 2,000 times, 50% of its capacity 300 times and 100% of its capacity around 100 times. Let’s say, for arguments sake, that a boat has two 200-ah battery banks, alternated from day to day, with a daily load of 80 Ah. Each bank will be discharged by 40% (80 Ah of one of the two 200 Ah banks) of its capacity before being recharged. The batteries will fail after 380 cycles, which is 760 days (since each is used every other day). If the two banks had been wired in parallel, to make a single 400 Ah battery bank, this bank would have been discharged by 20% of capacity every day, with a life expectancy of 800 days, a 5% increase in life expectancy using exactly the same batteries! But now let’s double the capacity of the batteries, so that the boat has either two 400 Ah banks, or a single 800 Ah bank, but with the same 80 Ah daily load. The two separate banks will be cycling through 20% of capacity every other day, resulting in a total life expectancy of 1,600 days. Doubling the size of the battery banks in relation to the load has produced a 210% increase in life expectancy. The single 800 Ah bank will be cycling through 10% of capacity every day, resulting in a life expectancy of 2,000 days - a 25% increase in life expectancy over the two (400 Ah) banks, and a 250% increase in life expectancy over the single 400 Ah battery bank! There are two immediate conclusions to be drawn from these figures: 1. For a given total battery capacity, wiring the (house) batteries into a single high capacity bank, rather than having them divided into two alternating banks, will result in a longer overall life expectancy for the batteries. 2. All other things being equal, any increase in the overall capacity of a battery bank will produce a disproportionate increase in its life expectancy (through reducing the depth of discharge at each cycle). FOR BATTERY LONGEVITY, A SINGLE LARGE (HOUSE) BANK, THE LARGER THE BETTER, IS PREFERABLE TO DIVIDED (HOUSE) BANKS.
- Status