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#1
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Buying Boat Batteries - Check My Thinking
I've asked about boat batteries before but now we're planning to launch next weekend and it's time to buy them. So see if this makes sense or if I'm wrong anywhe SITUATION: The boat is a 22 foot 1958 Chris Craft (that we've been restoring for the past 2.5 years). Engine is a in-line / straight 6 cylinder 130 horsepower and 320 cubic inches. It has a generator with voltage regulator. The electrical setup I've created calls for two 12 volt batteries. They are on an A/B/ALL switch with a battery-combiner (BC) between them. Normally I plan to run with the switch in just the "A" or "B" position. So when the engine is running the BC will combine the batteries and both will be charged. When the engine stops and we are drawing current for light & such, only one battery will be supplying power. If that one got drained we could switch to the other to restart the boat. The items that might be drawing power on the boat a Small bulbs for bow & stern lights, Small bulbs and LED lights in the cockpit & cuddy/cabin areas, Instrument back-lighting, Depth Finder. Maybe something like a radio and/or GPS plugged into a 12 volt outlet. Also there are two 1100 GPH bilge pumps, but I don't expect them to run much. Use: We are in the Northeast and will probably trailer the boat, using is every other weekend or so. There could be times we're on vacation with it in a slip for a week at a time or possibly sleeping on the boat for a night while moored near some island or something. QUESTIONS: TYPE OF BATTERY: I know that Gel or Absorbent Glass Matt (AGM) are supposed to be better. But for this application where these is not much vibration, no need to mount the batteries in any position except "normal" and where the battery may not get 100% proper storage (ie no trickle charger all winter) I'm thinking the extra cost is not worth it. I'm thinking just use regular flooded batteries. SIZE will be group 24. I believe the space that I have for the batteries (under the passenger seat) will take two Group 24 batteries. CCA/MCA: I really don't know what size Cold Cranking Amps or Marine Cranking Amps is necessary/good to turn over the engine I have. I'm guessing that anything in around about 550 is fine. If I can get more for not much more $$ than that's what I'll do. RESERVE CAPACITY: I really don't have much draw on these batteries so pretty much whatever the RC rating is will be fine for my use. TYPE: I'm thinking that Dual-Purpose is the way to go. It is possible that I'd draw a batter down when occasionally sleeping on the boat overnight and Starting batteries don't like that very much. TWO OF THE SAME: Since they will be charging in tandem (together) it's best to have two of the same. Also, I'll sometimes have the switch on "A" and sometimes on "B" so both get approximately the same useage pattern. BUYING: + Check the date manufactured on the battery and try to get ones that are less than 3 months old. + Try to get them with a longer free-replacement period as this is a good sign of quality + Watch out because replacement are sometimes pro-rated and based on the LIST price, not retail. WHERE TO BUY: ?? CostCo ?? ?? Specific Brands to look for OR avoid ?? Thanks for reading and for any help or comments! Gary |
#2
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Buying Boat Batteries - Check My Thinking
SIZE will be group 24. I believe the space that I have
for the batteries (under the passenger seat) will take two Group 24 batteries. Make sure you allow sufficient room for battery boxes, and go with the largest batteries that will fit the space you describe. If you can use Group 27's, that would be better. TYPE: I'm thinking that Dual-Purpose is the way to go. It is possible that I'd draw a batter down when occasionally sleeping on the boat overnight and Starting batteries don't like that very much. Why not just go with deep cycle? That way you're more likely to get the heavy plates that will stand up to severe discharge. A deep cycle battery is "dual purpose", in so much as that if the CCA rating is sufficient for the engine you will do *no* harm to the deep cycle battery using it to power the starter. As you have already determined, you will damage a "starting" battery with a series of deep discharge cycles. WHERE TO BUY: ?? CostCo ?? ?? Specific Brands to look for OR avoid ?? I like my Rolls batteries a lot. Surette is the same battery, but made on the other side of the US/CAN border. Ten year warranty, with the first seven years non-prorated, full replacement. OTOH, you could afford to buy cheap batteries a few times for what you'd spend for Rolls or Surette. Pay now, or pay later.......but if you only intend to keep the boat a year or two before trading up the average quality cheapies are probably the way to go. |
#3
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Buying Boat Batteries - Check My Thinking
Gould, Thanks for the good comments. I will consider if Group 27 will fit. I'm a little confused by the deep-cycle vs. dual use. If deep-cycle will be OK for starting then why ever buy/make a dual-use? OTOH, you could afford to buy cheap batteries a few times for what you'd spend for Rolls or Surette. Pay now, or pay later.......but if you only intend to keep the boat a year or two before trading up the average quality cheapies are probably the way to go. We've worked 2.5 years on this boat. We've got more into her than they sell for. It was a labor of love and I expect that I'll keep that boat until I'm dead. The memories of my father shaping parts, the work he and I and my brother did, the support from the rest of our families & friends, well, it just wouldn't be the same on another boat. Not to say I wouldn't buy another boat TOO I guess I'm generally of the mind of keeping the batteries somewhat on the cheap side. Not that I want them to fail, but it seems batteries in boats go every couple years anyway. Probably because while I try to store them properly over the winter, I can't get down there to "top them off" and and I don't like the idea of a trickle charger being connected for weeks at a time without me stopping by to make sure everything is OK. Again, Thanks for the comments! Gary |
#4
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Buying Boat Batteries - Check My Thinking
Thanks for the good comments. I will consider if Group 27 will fit. I'm a
little confused by the deep-cycle vs. dual use. If deep-cycle will be OK for starting then why ever buy/make a dual-use? You might compare the CCA and the scale weight of a dual purpose battery with both a starting battery and a deep cycle. I haven't done so, but the comparison might be interesting. Starting batteries use thinner plates to create a greater area of exposure to electrolytes. This results in a greater number of CCA in a given battery size. Downside, those thin plates disintegrate faster during severe discharge/recharge cycles.. Deep cycle batteries use heavier plates, at the expense of some CCA. The heavier plates will withstand serious recharging with less damage than the lighter plates in starting batteries. Dual purpose could be anything. A starting battery with such a short warranty or high margin that the mfg figures he can afford to replace a few under warranty. A "medium duty" battery slightly heavier than a starting battery but not as rugged as a deep cycle. A genuine deep cycle battery labeled "dual purpose" to rake in a few sales from folks who think they have to have a different battery technology for starting the engine than for running DC loads. Who knows? |
#5
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Buying Boat Batteries - Check My Thinking
Gary Warner wrote:
The electrical setup I've created calls for two 12 volt batteries. They are on an A/B/ALL switch with a battery-combiner (BC) between them. It would be simpler, cheaper, and more foolproof to simply have each battery on a key switch. The A/B/Both/Off switches create all sorts of problems from dead batteries to fried alternators. Normally I plan to run with the switch in just the "A" or "B" position. So when the engine is running the BC will combine the batteries and both will be charged. When the engine stops and we are drawing current for light & such, only one battery will be supplying power. If that one got drained we could switch to the other to restart the boat. Exactly! QUESTIONS: TYPE OF BATTERY: I know that Gel or Absorbent Glass Matt (AGM) are supposed to be better. But for this application where these is not much vibration, no need to mount the batteries in any position except "normal" and where the battery may not get 100% proper storage (ie no trickle charger all winter) I'm thinking the extra cost is not worth it. I'm thinking just use regular flooded batteries. Agree. I don't see enough advantage in your usage to get AGMs, unless the boatteries are in an inaccessible place and will be difficult to service. Also, you don't mention it but are you putting in a hard wired charger? Definitely get & use a 3-stage smart charger no matter how you rig it. SIZE will be group 24. I believe the space that I have for the batteries (under the passenger seat) will take two Group 24 batteries. Might be too small. If you're using 2 dual purpose instead a starting & a deep cycle, then you're getting less cranking amps and less amp-hours capacity. http://www.cs.ucf.edu/~matt/leadacid/guide.html CCA/MCA: I really don't know what size Cold Cranking Amps or Marine Cranking Amps is necessary/good to turn over the engine I have. I'm guessing that anything in around about 550 is fine. If I can get more for not much more $$ than that's what I'll do. Agreed. This is one case where more is better. RESERVE CAPACITY: I really don't have much draw on these batteries so pretty much whatever the RC rating is will be fine for my use. TYPE: I'm thinking that Dual-Purpose is the way to go. It is possible that I'd draw a batter down when occasionally sleeping on the boat overnight and Starting batteries don't like that very much. neither do dual purpose, for that matter deep cycle batteries get rather upset if you discharge them past 50% TWO OF THE SAME: Since they will be charging in tandem (together) it's best to have two of the same. Also, I'll sometimes have the switch on "A" and sometimes on "B" so both get approximately the same useage pattern. If you were oversizing the batteries so that there wasn't risk of damaging or hard sulfating them starting the engine, I'd say fine. But since you're limited in size I'd suggest getting a starting battery and a deep cycle and marking the switches as such. You might also consider getting two dual purpose batteries and then finding a place for two golf cart batteries somewhere else for house loads. BUYING: + Check the date manufactured on the battery and try to get ones that are less than 3 months old. + Try to get them with a longer free-replacement period as this is a good sign of quality + Watch out because replacement are sometimes pro-rated and based on the LIST price, not retail. Good. I bought two Exide Gr-31 batteries that were approx 6 months on the slef and they are not really satisfactory. If you can buy dry batteries and have the vendor fill & charge them, that'd be better too. Only a battery store will do this though. Fair Skies Doug King |
#6
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Buying Boat Batteries - Check My Thinking
Thanks Doug & John H for your comments & thoughts! |
#7
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Buying Boat Batteries - Check My Thinking
Got mine at walmart, wired in parallel.
"Gary Warner" wrote in message ... I've asked about boat batteries before but now we're planning to launch next weekend and it's time to buy them. So see if this makes sense or if I'm wrong anywhe SITUATION: The boat is a 22 foot 1958 Chris Craft (that we've been restoring for the past 2.5 years). Engine is a in-line / straight 6 cylinder 130 horsepower and 320 cubic inches. It has a generator with voltage regulator. The electrical setup I've created calls for two 12 volt batteries. They are on an A/B/ALL switch with a battery-combiner (BC) between them. Normally I plan to run with the switch in just the "A" or "B" position. So when the engine is running the BC will combine the batteries and both will be charged. When the engine stops and we are drawing current for light & such, only one battery will be supplying power. If that one got drained we could switch to the other to restart the boat. The items that might be drawing power on the boat a Small bulbs for bow & stern lights, Small bulbs and LED lights in the cockpit & cuddy/cabin areas, Instrument back-lighting, Depth Finder. Maybe something like a radio and/or GPS plugged into a 12 volt outlet. Also there are two 1100 GPH bilge pumps, but I don't expect them to run much. Use: We are in the Northeast and will probably trailer the boat, using is every other weekend or so. There could be times we're on vacation with it in a slip for a week at a time or possibly sleeping on the boat for a night while moored near some island or something. QUESTIONS: TYPE OF BATTERY: I know that Gel or Absorbent Glass Matt (AGM) are supposed to be better. But for this application where these is not much vibration, no need to mount the batteries in any position except "normal" and where the battery may not get 100% proper storage (ie no trickle charger all winter) I'm thinking the extra cost is not worth it. I'm thinking just use regular flooded batteries. SIZE will be group 24. I believe the space that I have for the batteries (under the passenger seat) will take two Group 24 batteries. CCA/MCA: I really don't know what size Cold Cranking Amps or Marine Cranking Amps is necessary/good to turn over the engine I have. I'm guessing that anything in around about 550 is fine. If I can get more for not much more $$ than that's what I'll do. RESERVE CAPACITY: I really don't have much draw on these batteries so pretty much whatever the RC rating is will be fine for my use. TYPE: I'm thinking that Dual-Purpose is the way to go. It is possible that I'd draw a batter down when occasionally sleeping on the boat overnight and Starting batteries don't like that very much. TWO OF THE SAME: Since they will be charging in tandem (together) it's best to have two of the same. Also, I'll sometimes have the switch on "A" and sometimes on "B" so both get approximately the same useage pattern. BUYING: + Check the date manufactured on the battery and try to get ones that are less than 3 months old. + Try to get them with a longer free-replacement period as this is a good sign of quality + Watch out because replacement are sometimes pro-rated and based on the LIST price, not retail. WHERE TO BUY: ?? CostCo ?? ?? Specific Brands to look for OR avoid ?? Thanks for reading and for any help or comments! Gary |
#8
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Buying Boat Batteries - Check My Thinking
"DSK" wrote in message .. . Gary Warner wrote: The electrical setup I've created calls for two 12 volt batteries. They are on an A/B/ALL switch with a battery-combiner (BC) between them. It would be simpler, cheaper, and more foolproof to simply have each battery on a key switch. The A/B/Both/Off switches create all sorts of problems from dead batteries to fried alternators. Normally I plan to run with the switch in just the "A" or "B" position. So when the engine is running the BC will combine the batteries and both will be charged. When the engine stops and we are drawing current for light & such, only one battery will be supplying power. If that one got drained we could switch to the other to restart the boat. Exactly! QUESTIONS: TYPE OF BATTERY: I know that Gel or Absorbent Glass Matt (AGM) are supposed to be better. But for this application where these is not much vibration, no need to mount the batteries in any position except "normal" and where the battery may not get 100% proper storage (ie no trickle charger all winter) I'm thinking the extra cost is not worth it. I'm thinking just use regular flooded batteries. Agree. I don't see enough advantage in your usage to get AGMs, unless the boatteries are in an inaccessible place and will be difficult to service. Also, you don't mention it but are you putting in a hard wired charger? Definitely get & use a 3-stage smart charger no matter how you rig it. SIZE will be group 24. I believe the space that I have for the batteries (under the passenger seat) will take two Group 24 batteries. Might be too small. If you're using 2 dual purpose instead a starting & a deep cycle, then you're getting less cranking amps and less amp-hours capacity. http://www.cs.ucf.edu/~matt/leadacid/guide.html CCA/MCA: I really don't know what size Cold Cranking Amps or Marine Cranking Amps is necessary/good to turn over the engine I have. I'm guessing that anything in around about 550 is fine. If I can get more for not much more $$ than that's what I'll do. Agreed. This is one case where more is better. RESERVE CAPACITY: I really don't have much draw on these batteries so pretty much whatever the RC rating is will be fine for my use. TYPE: I'm thinking that Dual-Purpose is the way to go. It is possible that I'd draw a batter down when occasionally sleeping on the boat overnight and Starting batteries don't like that very much. neither do dual purpose, for that matter deep cycle batteries get rather upset if you discharge them past 50% TWO OF THE SAME: Since they will be charging in tandem (together) it's best to have two of the same. Also, I'll sometimes have the switch on "A" and sometimes on "B" so both get approximately the same useage pattern. If you were oversizing the batteries so that there wasn't risk of damaging or hard sulfating them starting the engine, I'd say fine. But since you're limited in size I'd suggest getting a starting battery and a deep cycle and marking the switches as such. You might also consider getting two dual purpose batteries and then finding a place for two golf cart batteries somewhere else for house loads. BUYING: + Check the date manufactured on the battery and try to get ones that are less than 3 months old. + Try to get them with a longer free-replacement period as this is a good sign of quality + Watch out because replacement are sometimes pro-rated and based on the LIST price, not retail. Good. I bought two Exide Gr-31 batteries that were approx 6 months on the slef and they are not really satisfactory. If you can buy dry batteries and have the vendor fill & charge them, that'd be better too. Only a battery store will do this though. Fair Skies Doug King Hard to get a nice setup with just the key switches. And my alternator has survived since 1991 with a Guest 1/2/off switch. 351W Ford motor. I run 2 batteries and use a starting battery in #1 and a dual purpose in #2. Run the electronics off #2 with a key switch to shut off power to the electronics and a battery combiner from West Marine to charge the #2 battery. Then I just run the dual battery switch to #1 and turn on the other switch to run the electronics. If #1 is bad, I can then switch to #2 for starting. Just did this 2 weeks ago, as #2 battery was bad, and only had $2.69 of warranty left. Running the electronics off their own battery prevents a couple of problems. Running down the starting battery, the electronics do not cycle from low power when starting, and the EMF kickback from the starter / solenoid is isolated from the the electronics, and saves them. Bill |
#9
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Buying Boat Batteries - Check My Thinking
And my alternator has survived since 1991 with a Guest 1/2/off switch. My understanding is that what can kill an alternator is if the Alt is putting out power and you switch from, say, #1 to #2. At that moment when you switch there is no battery connected to the charging system to take the power thus creating a momentary surge in power. Some switches are "make-before-break" so they make the connection to the #2 battery BEFORE breaking the connections to the #1. (or whichever way you are switching). But these better type switches can look exactly like the cheaper type. You have to check the part number (or study it's design and operation) to determine which type you have. |
#10
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Buying Boat Batteries - Check My Thinking
"DSK" wrote in message .. . Also, you don't mention it but are you putting in a hard wired charger? Definitely get & use a 3-stage smart charger no matter how you rig it. On such a smally boat with such low electrical draw and only weekend use do I really need/want a charger? Won't my generator take care of charging up the batteries? Other question: I do have a good home based battery charger. It has both a full charge & trickle charge setting. But I see that trickly charging all winter is going to kill the battery. So are my choices are basically as follows ?? A: Charge it when taking it out, then leave it all winter B: Go to the shop every 2 or 4 weeks and charge it for a while C: Buy a "smart" or "float" charger and leave that running And is it really OK to leave a smart charger running and connected to a battery for weeks at a time without checking on it? The thought of that just makes me a little nervous. |
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