Need a new battery

[MikeyL]

My in-laws have a membership to BJs and they have an exide dual purpose marine/rv battery for $75. For the price if I only get a couple years out of it that is fine. I also carry a battery pack with me for emergencies.

EXCELLENT choice (we really like our BJ's) .........my only suggestion is watch the CCA's of the unit you choose. GREAT price and Quality, however ! Good Luck to you, Mikey Lulejian - Lake Oconee, GA

 

[David Analog]

Personally I have had great experiences with Optima batteries from in the '90s to present day regardless of when and where they were produced, etc. etc.
When I have had issues it was because we absolutely made an error. And I have seen countless boat owners who wrongly blamed the battery, regardless of brand, for their bad usage, charging and maintenance habits.
Now one area where Optima gets a bad rap is the smaller & lighter group 34 Blue Top battery that is most commonly used. Call it a racing battery or whatever, but it's smaller with less capacity than a standard group 24. IMO, it's just not the best battery choice for a deep cycle boat application where you need to place a priority on greater reserves. But many still use these in multiples specifically for their lower height or the ability to side mount so they can relocate the batteries in order to create more storage space. If you can afford them and are making an informed decision, who can argue with that.
You are definitely not buying an AGM for the best amp/hours to cost ratio. You are investing more in an AGM for other quality attributes.

 

[David Analog]

If you are boating as a warm weather sport and you are not cranking big blocks then I would go the deep cycle route on both banks and compensate by going a battery size larger. In the simplist scenario with two symmetrical banks and a standard dual battery switch, you can alternate the bank function from weekend to weekend and extend the lifespan of both batteries. There is no perfect dual battery system that shares the same boat charging system. There are always contradictions. What is best for the boat's charging system may not be best for the batteries with the inverse also being true. But you can get much closer to ideal with the right scheme and the correct Smart shore charger.

 

[Evil Sports]

I struggled with this decision for a few weeks prior to getting my boat. In the end I went with standard lead deep cycles. Im the type to put it away wet and not use it for a week or more. One huge thing to keep in mind if you are not running a bunch of stuff off the battery, these are Jet SKI motors. How big 0f a battery do you see in Jet ski hulls?? It takes very little to start these motors, your not trying to light up NYC. For the extra $$ and weight I stayed with old school tech. Im going down to plug in my on board charger today, tried to do it once a month during the cold, we shall see.

 

[MikeyL]

I struggled with this decision for a few weeks prior to getting my boat. In the end I went with standard lead deep cycles. Im the type to put it away wet and not use it for a week or more. One huge thing to keep in mind if you are not running a bunch of stuff off the battery, these are Jet SKI motors. How big 0f a battery do you see in Jet ski hulls?? It takes very little to start these motors, your not trying to light up NYC. For the extra $$ and weight I stayed with old school tech. Im going down to plug in my on board charger today, tried to do it once a month during the cold, we shall see.

Extremely SANE advice for Cranking batteries !

 

[Evil Sports]

Al, you might consider a solar charger as a back up while your not using the boat. It MIGHT help you from losing that battery early.

 

[maboat]

This is not really a good/bad or "which battery is better" issue. It's a value proposition. AGM batteries are indeed very good and they are very expensive. I like good things and I'm willing to pay more if it makes sense. It doesn't make sense to pay 2-3 times as much for AGM. I would rather buy a new lead-acid battery every 3-4 years and spend less than buying 1 AGM and HOPE that it last 8 good years. Simple economics as far as I'm concerned

 

[txav8r]

This is not really a good/bad or "which battery is better" issue. It's a value proposition. AGM batteries are indeed very good and they are very expensive. I like good things and I'm willing to pay more if it makes sense. It doesn't make sense to pay 2-3 times as much for AGM. I would rather buy a new lead-acid battery every 3-4 years and spend less than buying 1 AGM and HOPE that it last 8 good years. Simple economics as far as I'm concerned

Economics are certainly a part of it Mark. But there is still an argument about spilling electrolyte, off gasing, and having to service that same electrolyte. Sometimes convenience and safety issues play a role in the decision process, and I liked the sealed battery vs one I had to keep track of fluid levels on. Anyone that hopes an AGM will go longer than a well cared for lead acid needs to look at reality...an AGM is just a battery like the standard flooded lead acid battery. It has glass mats separating the plates at optimum distance and resistance is less in an AGM, it can handle more amps during charging, and it will hold a more stable line during usage...but it is just a battery and it will not live longer than a standard. It costs more, just like you pointed out, and yes, economics may make the decision for you...but while your making the decision, take into consideration being able to charge your battery in closed and less vented conditions, and the cleanliness of your battery compartment long term. It is hard to service a battery without some spillage if you don't remove them to do so...never have to do that with an AGM. Is it a luxury? That will be up to your personal budget won't it? Some of us would never have a standard lead acid in a boat ever again. But I agree, economics say you can get by with a $10,000 Kia...so why do so many folks drive more expensive cars?

 

[maboat]

All true points @txav8r and well said as usual.

There is no single right choice for everybody. The only true answer is "it depends". Ive never had a problem with spilling battery fluid in my boats. I always remove my batteries for long-term storage. I always top off my batteries for short-term storage. For me and my usage, the benefits of AGM do not apply. And I suspect that's true for many other boaters too.

I am guilty of paying more for luxury cars when a Kia would do fine. But I don't consider my boat batteries much of a "luxury" item. Perhaps that's just me

 

[Tollus]

I'm doing a little research myself and have a question that is related. I have a dual battery set up with a voltage relay between the two. My starter battery always gets a charge and the second battery gets one when the start is fully charged.

Question is, I'd like to upgrade my house battery to a group 27 since it's a little bigger and maybe do a deep cycle only on that battery and keep my starter battery a 24 marine starter battery. That will save a little since the 27s are a bit more expensive.

Are there any issues with using different sizes? They're both 12 volts, so I can's see how it would matter, but wanted to check.

Second question, any issues using a starter with a deep cycle? only difference here is the thickness of the plates....but they still are 12 volts and charge with a 12 volt charger.

Thanks,
Jeff

 

[Evil Sports]

I am guilty of paying more for luxury cars when a Kia would do fine. But I don't consider my boat batteries much of a "luxury" item. Perhaps that's just me

I agree and I have 3 on board, 2 for my 24V trolling mtr

 

[maboat]

Second question, any issues using a starter with a deep cycle?

I get to use my favorite expression ... "it depends"

Big engines, and high-compression engines (e.g. Diesel) need high starting current. Also cold weather starting for some engines can be a concern... BUT...

For most of the uses here on this forum, we're talking about small gas engines which are rarely used in frigid temps and typically can be started with small motorcycle/pwc batteries. For us, starting with a deep cycle is not a concern.

I have only deep cycle batteries in my boat.

 

[Magic]

A lot of interesting thought has gone into this thread! Interesting points for both AGM and "normal" batteries..... We have used the lead/acid batteries from Costco as stated, but we also keep the "Battery Tender" on the batteries. Its seems to work for us. Friends with the same batteries purchased at the same time who do not have a continuous charger get about 2 years or so out of theirs. We just replaced ours at the 4 year mark. They are warrantied for longer so we got some credit towards the new batteries as well.....

 

[David Analog]

I'm doing a little research myself and have a question that is related. I have a dual battery set up with a voltage relay between the two. My starter battery always gets a charge and the second battery gets one when the start is fully charged.

Question is, I'd like to upgrade my house battery to a group 27 since it's a little bigger and maybe do a deep cycle only on that battery and keep my starter battery a 24 marine starter battery. That will save a little since the 27s are a bit more expensive.

Are there any issues with using different sizes? They're both 12 volts, so I can's see how it would matter, but wanted to check.

Second question, any issues using a starter with a deep cycle? only difference here is the thickness of the plates....but they still are 12 volts and charge with a 12 volt charger.

Thanks,
Jeff

I like to keep the type of batteries the same whether lead acid or AGM.
Past that, the two banks are used and discharged very differently and recharged very differently, so there is no justification in keeping the two banks the same in either size or cranking vs deep cycle. If they began as identical batteries they would not be identical batteries for long.
Your ACR/VSR determines that the starting battery is unlikely to be discharged below a safe level for a cranking type battery. However, those with a manual dual battery switch are more likely to run down a cranking battery when combined with a deeply discharged deep cycle battery. So in that application, I like using deep cycle batteries in both banks. But a size difference still will not matter.
In contrast, two batteries within the same bank should be identical in chemistry, size and type, and even production/purchase date, because they are used in parallel from moment one. Idenitcal batteries when used in parallel will last longer than disimilar batteries.
The above recommendations would be the most ideal. But again, you cannot achieve perfection in any dual bank system sharing the same boat charging. You try and come as close as possible. Beyond this, I believe it is extremely important to use the correct AC shore charger that fits your particular batteries and your unique usage habits. Following the advice of, "buy this or that brand or model of charger because I use it" is flawed. One size does not fit all.

 

[dan144k]

Many battery chargers will tell you bad battery if the voltage drops below 6volts (my extreme pulsetech intelligent charger will).
To get around this
1. Use an old fashion amp type charger
2. you can jumper cable to a good battery and charge both together, and then charge each individually.

Also make sure you have a battery switch installed or disconnect the battery cables when not in use for more than a week or two.
Many of the Yamaha's will slowly discharge the battery, even if you have turned everything off (made me nuts)
After a month in the driveway the battery would be dead, dealer was unable to locate voltage drain.(thanks for the help Yamaha)

I installed a basic battery switch (off,1,2,both) and 2nd battery. Keep on charger now in driveway too.
I kept the original factory battery as my 2nd battery for emergency (had drained 3-5times/did not trust for main battery anymore) and wired directly to my 2nd bilge pump, for if/when boat left in water overnight.
New battery was a sears group31 marine, and used as main battery for starting and stock stereo.

 

[bronze_10]

Reviving an old thread... the batteries I have in my boat are from 2008... they seem to be working fine but at that age I feel like I am on borrowed time.. both I have now are group 24 Batts and they have done fine for us. We have added some electronics to the boat... better radio, plotter, vhf, led light rings... we don't have music amps and stuff so no major draw... therefor I don't think group 31 are required.. I don't want crappie Batts but I don't want the max out the mod budget either.. I was thinking either 27 or 29 would be an upgrade without breaking the bank..
Any advice would be great.. !

 

[davel501]

Reviving an old thread... the batteries I have in my boat are from 2008... they seem to be working fine but at that age I feel like I am on borrowed time.. both I have now are group 24 Batts and they have done fine for us. We have added some electronics to the boat... better radio, plotter, vhf, led light rings... we don't have music amps and stuff so no major draw... therefor I don't think group 31 are required.. I don't want crappie Batts but I don't want the max out the mod budget either.. I was thinking either 27 or 29 would be an upgrade without breaking the bank..
Any advice would be great.. !

If everything is good I would vote for replacing with new versions of what you have. The other path leads to new battery trays and wiring changes, etc.