replace 8 8 volt batteries for 50' Convertible w/ 8v92TI

If possible I would like to hear from anyone familiar with replacing the Rolls or comparable large 8 volt battery banks on 50' sport fish. I have heard golf cart batteries can work, but are they not deep cycle? and not capable of starting the 92's? Any info, suggestions, view points etc will be much appreciated andf thanks in advance

The standard flooded 19", 8V battery is no longer made by any mfg.
They still make the flooded 23" battery. If 8 of these will fit, problem solved in a most cost reduced purchase.

Once your heart starts beating normally from that cost estimate and still want to spend more money on maybe better quality batteries, then just go with the Rolls.

On a warm day, I would think 700 CCA per starter would be a good spec to start shopping with.

This post should be in the tech section but I used US. Batteries great service made in USA and a family owned company. They are made to compete with the Rolls only a lot less money and more available

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Originally Posted by Captain Ralph

The standard flooded 19", 8V battery is no longer made by any mfg.
They still make the flooded 23" battery. If 8 of these will fit, problem solved in a most cost reduced purchase.

Once your heart starts beating normally from that cost estimate and still want to spend more money on maybe better quality batteries, then just go with the Rolls.

On a warm day, I would think 700 CCA per starter would be a good spec to start shopping with.

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The cost for eight 8v batteries is high enough that they should include a defibrillator at no extra charge.

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Originally Posted by jim rosenthal

The cost for eight 8v batteries is high enough that they should include a defibrillator at no extra charge.

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You get that when you cross the wires. Lol

I think Fisheries Supply sells the US Battery but they are branded DYNO. If I recall, the battery factory is just down the street from them.

Their M13 provides 1000CCA.

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Originally Posted by jim rosenthal

The cost for eight 8v batteries is high enough that they should include a defibrillator at no extra charge.

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Originally Posted by SEVEN

You get that when you cross the wires. Lol

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You kids have been here before.

I usually start off numb (86 min proof) before I sign the credit card.
Then a pile of stuff from the wife for a while.

So far, my Frankenstein battery experiment (stage two) has been working. Some hick-ups but positive. More on this later when stage three is implemented later this year.
PM me if anybody wants any more details on these ideas.

Check my post in the Tech Talk Forum on Full River 8 V AGM batteries. I just did this on an LRC and did quite a bit of research.

I would recommend calling DC Batteries in Miami, they were a GREAT resource for me.

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Originally Posted by JD5652

Check my post in the Tech Talk Forum on Full River 8 V AGM batteries. I just did this on an LRC and did quite a bit of research.

I would recommend calling DC Batteries in Miami, they were a GREAT resource for me.

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Do they have big flag terminals on them like the Rolls, US Battery, and Dyno? If not, you risk melting the terminals with the high amp loads of starting.

Anyone have experience with these:

https://www.fisheriessupply.com/dyno-battery-m5t-commercial-marine-battery-8-volt/m5t

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Originally Posted by zigzag930

Anyone have experience with these:

https://www.fisheriessupply.com/dyno-battery-m5t-commercial-marine-battery-8-volt/m5t

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That would be the 19" battery of choice for many.

Note that the ad states Special Order Only.
Must be an old ad, 19" batteries have not been made by anybody for a lil while now.

For fun, I just sent them a query note asking about availability. I'll update all if/when I get a reply.

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Originally Posted by Captain Ralph

That would be the 19" battery of choice for many.

Note that the ad states Special Order Only.
Must be an old ad, 19" batteries have not been made by anybody for a lil while now.

For fun, I just sent them a query note asking about availability. I'll update all if/when I get a reply.

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Its not old. They use a battery plant in Seattle. All sizes are special order. The plant makes them as you order them.

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Originally Posted by zigzag930

Anyone have experience with these:

https://www.fisheriessupply.com/dyno-battery-m5t-commercial-marine-battery-8-volt/m5t

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At that price would it be better / longer lasting / less maintenance / less battery acid vapor in the er.. to go with an AGM golf cart battery?

https://advantagebatteries.com/shop/trojan-t875-agm/

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Originally Posted by rustybucket

At that price would it be better / longer lasting / less maintenance / less battery acid vapor in the er.. to go with an AGM golf cart battery?

https://advantagebatteries.com/shop/trojan-t875-agm/

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For a house battery, maybe yes, for an engine starting battery, probably not.
Please note NO CCA data available on this battery.

Does the Trojan web site have any CCA information available on this 8v AGM?

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Originally Posted by jim rosenthal

Does the Trojan web site have any CCA information available on this 8v AGM?

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I was looking over the weekend and could not find it. The only 8v AGM I’ve been able to find CCA specs on is the Full River brand and it was quite stout at 1150 CCA.



.

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Originally Posted by jim rosenthal

Does the Trojan web site have any CCA information available on this 8v AGM?

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They do not, but many are using the 8v golf cart lead acid batteries (myself included) with success. I hate the fumes from lead acid batteries (like we need more help creating corrosion), so always want to go with agm's wherever possible.

This is very interesting
Anybody want to dig deeper into the original sized 19", 8v battery?

Jeremy Makin (Fisheries Supply Customer Service) Feb 5, 2024, 1:33 PM PST This special order battery is available. Lead time can be 2-3 weeks as they are built to order at the manufacturer. This is an 8 Volt DC battery and is not commonly used hence the special order status and longer lead time. Jeremy

Ralph Feb 3, 2024, 6:53 AM PST Product Question; Is this 19" battery still available? Thx Ralph https://www.cognitoforms.com/Fisheri...68UNI_9NOClc$*

I replaced mine with deka. I did Four one year and four the next to lessen the pain. At the end of last season one of the newer took a crap and drained the other three on the only weekend I was out of town. I was able to bring them all back but my season ended so I need to see how they held up over the winter. I always isolate each battery in both banks prior to storage.

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Originally Posted by Captain Ralph

This is very interesting
Anybody want to dig deeper into the original sized 19", 8v battery?

Jeremy Makin (Fisheries Supply Customer Service) Feb 5, 2024, 1:33 PM PST This special order battery is available. Lead time can be 2-3 weeks as they are built to order at the manufacturer. This is an 8 Volt DC battery and is not commonly used hence the special order status and longer lead time. Jeremy

Ralph Feb 3, 2024, 6:53 AM PST Product Question; Is this 19" battery still available? Thx Ralph https://www.cognitoforms.com/Fisheri...68UNI_9NOClc$*

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Ralph,
If you want to know about these Dyno Batteries, just call Fisheries. My buddy just did that and found a bunch of information about all of the 8v batteries that they have sourced. He is going to order a set of the longer M15's as those are the size of his Rolls. He found that they are made to order from the plant in Seattle. I don't know why everone wants to find out all of their information online. Many times it's just better to call and speak to someone.

Exactly so. Phone is still the best way to ask questions and get answers.

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Originally Posted by MadHatter53

I replaced mine with deka. I did Four one year and four the next to lessen the pain. At the end of last season one of the newer took a crap and drained the other three on the only weekend I was out of town. I was able to bring them all back but my season ended so I need to see how they held up over the winter. I always isolate each battery in both banks prior to storage.

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Deka hasn’t made them in years and they were junk when they did.

FWIW, I got 8 of the Rolls 8-HHG-25P Oct. 2023. Took about 18 weeks to get after we ordered them. They were a new build from Rolls, came with all new cables with tinned ends & heat shrink. Right at $4,300 including shipping. I ordered them through our local Northern Battery distributor, they delivered them to the marina.

There they set on a pallet under the boat in a heated building until just before launch this spring. I think I'm going to have some young bucks lug them in and out.

Randy

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Originally Posted by jim rosenthal

Exactly so. Phone is still the best way to ask questions and get answers.

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I'm guessing this was meant for me.

I got my answer fine.

Please review post #11.

I'm not shopping for 8v batteries.
I'm in no hurry for replies to my queries when I send an off hour request to a vendors web site.

Contrary to my understanding; no more 19" batteries.
Seems some company will custom build 19" / 8v batteries.
I was trying to help point those in need with a good credit card to a source to help.

To everyone who offered information on replacing the large 8v 1000 cca batteries on my 50 sport fish I contacted Dyno factory directly The replacement model were close to $400 each and shipping was reasonable Whole deal less than 4k which is not cheap but they turned the ‘92s over and started at the turn of the key Thanks to all that got involved on this discussion I just could not find a less expensive way out mike

I called Dyno directly yesterday. Prices for there M15 are excellent and very close to the Deka 8V's that are onboard now. Shipping to SW Florida was pricey, but even factoring that into the equation - about $400/battery, delivered.

Still collecting info on US Battery (looks like the exact same as the Dyno), but my local dealer is trying to get prices and delivery times as these are special order and may take 2-4 weeks.

The Rolls 8HHG21P look nice as well, but it is a "dual purpose" battery and not sure how that relates to it's TRUE suitability for starting the Detroits.

I'll also take a look at the FullRivers. I've used them in the past on another boat and had very good experience with them.

I think my biggest issue will be locating some muscle to help me offload the old and install new batteries. My mind is slowly coming around to the fact that my body isn't as young as I think it is, LOL

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Originally Posted by zigzag930

I called Dyno directly yesterday. Prices for there M15 are excellent and very close to the Deka 8V's that are onboard now. Shipping to SW Florida was pricey, but even factoring that into the equation - about $400/battery, delivered.

Still collecting info on US Battery (looks like the exact same as the Dyno), but my local dealer is trying to get prices and delivery times as these are special order and may take 2-4 weeks.

The Rolls 8HHG21P look nice as well, but it is a "dual purpose" battery and not sure how that relates to it's TRUE suitability for starting the Detroits.

I'll also take a look at the FullRivers. I've used them in the past on another boat and had very good experience with them.

I think my biggest issue will be locating some muscle to help me offload the old and install new batteries. My mind is slowly coming around to the fact that my body isn't as young as I think it is, LOL

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Zig -

My Full River 8V AGM's are working very nicely. They spin up the 671s with no issue whatsoever.

FYI, I bought a hydraulic table from Harbor Freight to make my removal and install a LOT easier. I'll post up some pics when I get on the ground (currently at 36,000 feet on way back from Whistler).

Two of us old guys were able to handle the removal and install pretty easy without much back pain the next day. The key to me was lifting the batteries onto my battery shelf. Not sure how yours is set up, but mine are on a shelf on the aft wall of the ER. Shelf is about 28 inches high from ER floor.

You are welcome to borrow the hydraulic table if you want to go that route. I might could even be talked into helping if the timing is right.

JD, Thanks for the offer. Will keep you posted and would love to see your battery removal process photos.

In the meantime, I plan to unplug the boat from dock power this weekend and monitor the batteries again. Will be interesting if my EQ process has corrected the batteries.

Here you go...

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Nice way to do it. Thanks for the photos.