8D Battery Recommendations

[kowal_53]

Just like my 2006 28, my 31 has decided it needs a new battery. I have 2 8Ds, and one 31. Both of these lead acid batteries look like they are originals. So they did last a very long time. (Boat was built in 2
late 2007)?

Does anyone have any brads they prefer, or one they recommend they stay away from.

[Jeremyvmd]

Honestly depending on what you want to spend, if I had to replace an 8d and had the scratch I would get a northstar modular 8d. Northstar makes killer batts and their modular 8d is a sweet peice of kit

[Pitou]

Just like my 2006 28, my 31 has decided it needs a new battery. I have 2 8Ds, and one 31. Both of these lead acid batteries look like they are originals. So they did last a very long time. (Boat was built in 2
late 2007)?

Does anyone have any brads they prefer, or one they recommend they stay away from.

Some food for thought ...

I've had modular Rolls batteries in the past, but their prices have skyrocketed. It was nice to be able to lug them in and out small pieces.

As you, I have 2 - 8D's, but a Group 27 for the Northern Lights generator starting battery. I inherited all these batteries from the previous owner when I took possession in 2013. The batteries are all stamped 2012. Both 8D's are "Dual Purpose" (Start & Deep Cycle & weigh in at 130 lbs. each). They are wired to the Start and House switches. One as #1 on the Start switch and the other as #2. They are wired opposite on the House switch.

Lugging 8D's is not my idea of joy and when the time comes to change these out I'm planning on changing the start battery to a Heavy Duty Commercial Service Deka starting battery and the house system to 4 and if I can make the room 6 - Interstate Heavy Duty 6 volt golf cart batteries (GC2-XHD) wired in in series and parallel. I've had great success with both of these in the past and know of others that have them in use. Remember, the QSC 500 requires a minimum of 1250 CCA or 1562 MCA. My current 8D's are 1750 MCA or roughly 1400 CCA. I'm going to lighten my struggle by utilizing 2- 55 lb. Group 31's wired in parallel for the start battery which will take up the same footprint, weigh less and give me the same “plus” CCA rating that I have now. 2 Deka 31’s at 750CCA each. Attached are PDF brochures from Deka & Interstate.

I'm in the midst of the planning stages for a battery makeover on my 2006 31 TE with the same QSC power plant as you. The main push is that the original plywood battery tray provided by Albin that the battery boxes sit on is beginning to rot and degrade. I ordered a piece of 3/4" X 16 1/2" X 62 1/2" piece of starboard from Boatoutfitters.com and am in the process of laying this out. Dyno makes battery boxes for 2 to 4 golf cart batteries and are available at Fisheries Supply. These work well and I used them for my 2 bank golf cart house bank on my 28 when I replaced my Rolls 4-D. Once those 8D’s come out they are not going back!

Deka Brochure.pdf

InterstateNon-AutomotiveUS-1.pdf

[catalina_mike]

Great post here about the Trojans I would go with.
viewtopic.php?f=20&t=5251&p=30991&hilit=Trojan#p30991

[djpeewee]

For house batteries it's Trojan T105's all the way! You should be able to fit 4 of these in series/parallel in place of the 8Ds. You can't kill these batteries. We had a set last 8 years of a lot of dry camping in our RV. They were still going strong when we sold it.

For the starting batteries, check out the Deka 24M7. It's a marine group 24 (small) start battery with 1000 MCA. I have one, that starts the Volvo KAMD300A in our boat fine. It is a lot of battery in a small, light package. 2 of them would definitely do the job for you.

My house batteries are the Interstate 4Ds. Definitely WILL NOT be replacing these with the same. Will definitely go with 4x Trojans.

[kowal_53]

Pitou

I see that your batteries are crossed start verses house. You said "One as #1 on the Start switch and the other as #2. They are wired opposite on the House switch" Mine are wired the same. I was ready to put a big 1 and 2 on my batteries so I know what goes where. Now I am confused a tad wondering what the logic behind this cross wiring is.

Any thoughts anyone?

[Pitou]

Pitou

I see that your batteries are crossed start verses house. You said "One as #1 on the Start switch and the other as #2. They are wired opposite on the House switch" Mine are wired the same. I was ready to put a big 1 and 2 on my batteries so I know what goes where. Now I am confused a tad wondering what the logic behind this cross wiring is.

Any thoughts anyone?

Kowal - I hope the following helps -

I've learned the following using a digital volt meter on the batteries while running the engine and testing the start and house batteries while turning the Engine battery switch through the three On positions.

If your swtches are the same as mine (Blue Seas 9001E switches)Two reasons for the house bank also being wired to the the Engine/Start switch:
1). In order for the House bank to charge from the alternator the Engine switch must be turned to 2 or Both/1+2 or if turned to 1 only the Engine battery will charge from the alternator and on 2 only the House battery will charge from the alternator. I generally start the engine on 1 and then switch to Both. Sometimes for simplicity I start on Both.

2). Having the House battery on the Engine/Start Switch allows for a backup if the Engine/Start battery were weak.

Having this same wiring arrangement on the House switch simply allows for a backup to run House systems off of your engine battery if the house battery were to discharge.

If you have the Blue seas switch described above, remember, this switch does not have Alternator Feed Disconnect. Meaning, never turn the Engine switch to the Off position or you will fry your alternator.

Attached is the spec. sheet on the alternator sheet.

Blue Seas Selector Switch 9001E.pdf

20151123_141955.jpg

[kowal_53]

I have been trying to start the engine on the battery switch position 2. Lots of clicking so there is obviously to little power there. I pulled the battery switch panel down and found that the start switch 2 position goes to the number 1 generator battery switch position. (The generator 31 battery does not have enough juice to start the engine) If I want to get to the house number 1 I must select both on the generator switch. (This means I will get both the house 8D and Generator 31) I can get both 8Ds by selecting both on both on the house and start battery switches.

So I guess the number one position is reserved for the dedicated battery for each battery switch. This is true for all of my switches. The number two is there to do something else, but not what you might assume. It does work for the generator, since number 2 position is hook to the house 8D. The house switch can pick up the start battery by selecting number 2 on the house selector switch. The engine start switch require what I described above.

Thanks to Pitou, charging is a bit different. if I want to charge both 8Ds I have to put the start with on 1 and the house switch on both. If I put the engine and house on both, I can charge both 8Ds, and the generator provide either 1 or 2 or both is selected. There are a few other positions that can do various other ways, but it is enough to boggle the mind.

So I think I will continue to operate with the house and start switch on both. Then all batteries are on charge. If I suspect one particular battery is weak, I can let all of the charge to go to the one in question.

The picture is upside down. Click on it and it will come up correctly with the house on left/generator/engine or start

[Pedro]

I guess I'm just a low tech guy because an 8d lead acid deep cycle from defender cost me $240, and gives me tons of amp hours and 1600cca to add to the starting bank in a pinch, (plus they are made in CT,) so I can drop it off if it ever fails and get a free replacement ,I feel like lead acids are still a good value and keeps everything simple and inexpensive, Pete

[crowra]

Throwing this out there for the cruisers -- Firefly Oasis AGM batteries can be discharged to 80%! With more cycle times than regular lead acid deep cycle. But they come with a hefty price tag ($486). Here's a good article if interested: http://www.panbo.com/archives/2016/05/g ... tails.html

[kowal_53]

I was able to start the boat on engine/start position 2. I guess sometimes you need to know how it is wired before you assume something.