What are the draw backs of using daisy chained 6 volts? Can I use my Guest shore power charger? It seems like the way to go considering space and amp hours.. Thanks in advance Ron
- Status
6 volt is the way to go
I have two golf cart batteries I purchaed at Rural King for $54 each on my ODay 25. With the two batteries I get the same amp hrs I would get with three group 24 batteries. They have a similar foot print to a group 24. The 6 volt batteries are taller so you need to make sure you have room. The biggest drawback in my mind is the fact that they are around 15 pounds heavier than a group 24. Also if you want to have a two battery system, isolating each battery, you can't do that (unless you get 4 6 volt batteries). What I do is run everything off the one bank including engine starting (my 9.9 OB doesnt require that much and golf cart batteries are designed to take the abuse). I keep one of those AGM car jumping things on board for emergencies(I chose AGM because of the low self discharge rate). My feeling is that when it comes to pounds or $'s per amp hour these six volt batteries are hard to beat. Hope this helps, Jim
I have two golf cart batteries I purchaed at Rural King for $54 each on my ODay 25. With the two batteries I get the same amp hrs I would get with three group 24 batteries. They have a similar foot print to a group 24. The 6 volt batteries are taller so you need to make sure you have room. The biggest drawback in my mind is the fact that they are around 15 pounds heavier than a group 24. Also if you want to have a two battery system, isolating each battery, you can't do that (unless you get 4 6 volt batteries). What I do is run everything off the one bank including engine starting (my 9.9 OB doesnt require that much and golf cart batteries are designed to take the abuse). I keep one of those AGM car jumping things on board for emergencies(I chose AGM because of the low self discharge rate). My feeling is that when it comes to pounds or $'s per amp hour these six volt batteries are hard to beat. Hope this helps, Jim
Ron,
Last year I instaled 6 6V batteries in my boat. 4 replaced 3 group 31s. The other 2 were more for ballast than amp hours. You can get them at Sams for around $60.00 each. I have a guy on another dock with 2 that are 9 years old. As far as I can tell there are no drawbacks to going 6V. Pat McCartin
Last year I instaled 6 6V batteries in my boat. 4 replaced 3 group 31s. The other 2 were more for ballast than amp hours. You can get them at Sams for around $60.00 each. I have a guy on another dock with 2 that are 9 years old. As far as I can tell there are no drawbacks to going 6V. Pat McCartin
Disadvantage of series 6V
Disadvantage of (2) Series Connected 6V Batteries: When a cell fails in a Series connected 6-Volt Battery, both batteries are out of commission. When a cell fails in a Parallel connected 12-Volt battery, only that battery is out of commission - the other can be maintained in service. The risk is the same - but the consequences are NOT. Picture 2 Series connected 6V batteries. Lose 1 battery due to bad cell - you're left /w 1 good, but useless, 6V battery. Picture 2 parallel connected 12V batteries. Lose 1 battery to a bad cell - you're left with 1 good, & useful, 12V battery. You can only 'jump' a bad cell, when you have cellular access [
]. You cannot access individual cells on a "battery". That said, my house bank consisted of 2 parallel pairs of seies connected 6-V Trojan T105's. Gord
Disadvantage of (2) Series Connected 6V Batteries: When a cell fails in a Series connected 6-Volt Battery, both batteries are out of commission. When a cell fails in a Parallel connected 12-Volt battery, only that battery is out of commission - the other can be maintained in service. The risk is the same - but the consequences are NOT. Picture 2 Series connected 6V batteries. Lose 1 battery due to bad cell - you're left /w 1 good, but useless, 6V battery. Picture 2 parallel connected 12V batteries. Lose 1 battery to a bad cell - you're left with 1 good, & useful, 12V battery. You can only 'jump' a bad cell, when you have cellular access [
]. You cannot access individual cells on a "battery". That said, my house bank consisted of 2 parallel pairs of seies connected 6-V Trojan T105's. GordDead cell risk is the same...
Gord's correct in his statement about losing efficiency on a whole (2 x 6V) bank if you have one bad cell in one of the 6V batteries...but that's no different that having one or more banks, each consisting of one 12V battery, and losing a cell in the 12V battery. My sense is that the 'bad cell' odds are actually a little great with a 12V battery than the 6V batteries (due to construction?), altho' I can't offer any stats on that assertion. My impression stems from hearing about occasional bad cells on cruising boats, who are typically hardest on their battery banks. I do remember a time when a bad cell was just jumped out of the circuit with little loss of battery performance...but that's when we had 256 cells, each weighing more than a ton, on our submarine.<g> Jack
Gord's correct in his statement about losing efficiency on a whole (2 x 6V) bank if you have one bad cell in one of the 6V batteries...but that's no different that having one or more banks, each consisting of one 12V battery, and losing a cell in the 12V battery. My sense is that the 'bad cell' odds are actually a little great with a 12V battery than the 6V batteries (due to construction?), altho' I can't offer any stats on that assertion. My impression stems from hearing about occasional bad cells on cruising boats, who are typically hardest on their battery banks. I do remember a time when a bad cell was just jumped out of the circuit with little loss of battery performance...but that's when we had 256 cells, each weighing more than a ton, on our submarine.<g> Jack
Gord, me too
I'm going to add another bank to mine next spring. My plan, should a cell fail would be to not take the whole 12 volts off line, but to wire up the good left over 6 volt battery to the good bank and make a 18 volt bank. It would be wired that way only in an emergency, to get the last drop of power if broken down at sea. But hey, battery failure at sea? Never happen. :{ My bank is shown on photo #53.
I'm going to add another bank to mine next spring. My plan, should a cell fail would be to not take the whole 12 volts off line, but to wire up the good left over 6 volt battery to the good bank and make a 18 volt bank. It would be wired that way only in an emergency, to get the last drop of power if broken down at sea. But hey, battery failure at sea? Never happen. :{ My bank is shown on photo #53.
6 Volt gives you most bang for your buck!
I've been using two banks of 2 parallel 6 V Trojan batteries for five years now and they're still going strong. I wouldn't worry about the dead cell issue with two banks. If you have only one bank (or two) and worry about the dead cell issue, carry one of these compact powerful emergency starting batteries. I've cruised over 8000 miles with refigeration and full electronics system and never had a dead cell yet. If you monitor your bank voltage after charging you normally can anticipate a battery failure.
I've been using two banks of 2 parallel 6 V Trojan batteries for five years now and they're still going strong. I wouldn't worry about the dead cell issue with two banks. If you have only one bank (or two) and worry about the dead cell issue, carry one of these compact powerful emergency starting batteries. I've cruised over 8000 miles with refigeration and full electronics system and never had a dead cell yet. If you monitor your bank voltage after charging you normally can anticipate a battery failure.
Buy them at the same time...
Ron, Never mix old batteries with new. They will hold as much charge as the lesser battery is capable of holding. That goes for 12 or 6 volt combinations. The chance of some type of failure is greater than with two equal age batteries. Yes your Guest shore power charger will still work. If it is a 6 amp charger, and the batteries are down 50 amp hours, it will take about 9 hours to bring it back to about 90%. Remember that if you keep them charged and try not to discharge them more than 50%, they will last for more than 5 years. If you don't, they may only make it 2 years. I know a guy that fried his brand new battery in less than three months with his solar panel with no controler. r.w.landau
Ron, Never mix old batteries with new. They will hold as much charge as the lesser battery is capable of holding. That goes for 12 or 6 volt combinations. The chance of some type of failure is greater than with two equal age batteries. Yes your Guest shore power charger will still work. If it is a 6 amp charger, and the batteries are down 50 amp hours, it will take about 9 hours to bring it back to about 90%. Remember that if you keep them charged and try not to discharge them more than 50%, they will last for more than 5 years. If you don't, they may only make it 2 years. I know a guy that fried his brand new battery in less than three months with his solar panel with no controler. r.w.landau
Thanks to all GREAT INFO
Muchas Gracias fellow boaters. I will deffinatly use the info as my damaged battery gave up the goast and blew the cap off the positive side last night. Ron
Muchas Gracias fellow boaters. I will deffinatly use the info as my damaged battery gave up the goast and blew the cap off the positive side last night. Ron
- Status