House Battery Draw?

That is my fear, that it killed a $300 battery. Are 8D any different from the normal deep cycle batteries?

MM
8D's are really a dual purpose which can be used for both starting and deep cycle. Deep cycle means only to 10.5 volts which is about 60%DOD; however, they can deliver very high cold cranking amps and are common for starting engines. The little sister of the 8D is the Group 27 dual purpose. Three Group 27 batteries in parallel is about the same as one 8D.
 
8D's are really a dual purpose which can be used for both starting and deep cycle. Deep cycle means only to 10.5 volts which is about 60%DOD; however, they can deliver very high cold cranking amps and are common for starting engines. The little sister of the 8D is the Group 27 dual purpose. Three Group 27 batteries in parallel is about the same as one 8D.

I'll try to keep optimistic. Would you replace an 8D or get the 3 batteries?

MM
 
Personally I would use 3 group 31 agm's. Little more space but much easier to handle.
Cheaper too.
 
Can't get any cheaper than the Duracells at Walmart. Made by East Penn. Same as a Deka.
 
Can't get any cheaper than the Duracells at Walmart. Made by East Penn. Same as a Deka.
Walmart is known for contracting a "special" version of items so they can sell at a lower price. Are you 100% positive that they are made to the same specs as the actual Deka's? Or are you just aware that they are made by Deka? Which, by the way, that part is true - Duracells are made by Deka... but are ALL Duracells made by Deka?
 
On the Chesapeake Bay they have a great rep. I've been using them for years. Optima is good but don't have the ah capacity of a 31. Mine have been off the charger 4 weeks
And this was the voltage Sunday.
Screenshot_20181104-111536.jpg
 
So you are implying you would not swap out and would retain the 8D setup?

MM
I'm by no means a battery expert - but given what I know, if I were in your shoes I would stick with the 8D. It seems like the logical choice - unless someone can explain how (3) 27's are superior to the 8D... taking into account the added cost of the extra cabling and other "noteworthy" items.
 
Walmart is known for contracting a "special" version of items so they can sell at a lower price. Are you 100% positive that they are made to the same specs as the actual Deka's? Or are you just aware that they are made by Deka? Which, by the way, that part is true - Duracells are made by Deka... but are ALL Duracells made by Deka?

Many companies contract with East Penn for private label. My local Deka guy tells me they are the same. West Marine too. Geography may play a part also. East Penn is here in the East. Highly regarded by most.
The Duracell name was licensed to encompass Automotive/Marine markets. They could certainly contract Exide or Johnson controls at some point depending on price or region.
 
Many companies contract with East Penn for private label. My local Deka guy tells me they are the same. West Marine too. Geography may play a part also. East Penn is here in the East. Highly regarded by most.
The Duracell name was licensed to encompass Automotive/Marine markets. They could certainly contract Exide or Johnson controls at some point depending on price or region.
I believe the main plant is about a 1/2 hour from me. Maybe some day I'll be in the area and will stop by. It would probably be good to talk with someone directly at the plant - sort of the "horse's mouth", so to say. Thanks for the info!
 
unless someone can explain how (3) 27's are superior to the 8D.
Setting a brand debate aside. 3 individual batteries may be easier to haul in and out of an engine bay, then 1 large. 3 may be easier to find a spot in the engine bay then one large. So these are things that need to ba taken into consideration.

Ah wise, barring any issues above, the setup that offers the best Ah x $$, is the best setup. With that said, A group 29 or 31 have about the same footprint as a 27, but a little higher AH. So three 29 or 31 in parallel, could easily be better that 300 Ah.

The cabling to link 2 extra batteries, and the hold-downs, it negligible, unless you have to spread the the batteries out around the engine bay. But, in that case, it sounds like the 8D would not fit either.
 
My thoughts - If the boat is or was originally set up with 8D then that is probably the most economical path for replacement. As a note, I tend to not acquire batteries through shipping but rather purchase within driving distance; the reason - should you need to exercise a return you will be responsible for the shipping which can be the cost of the battery and you can be down for extended periods of time (message is read the fine print).
Rather than spend a lot of money on a premium batteries, focus on upgrading the charging system, modern battery switching/isolation, checking/cleaning/ replacing cables and terminals, and a plan to monitor and maintain the batteries. With modern battery maintenance systems there is no reason not to get eight years minimum out of a lead acid battery.
However, before running off with hair on fire to buy new, take your battery and get it tested at a qualified dealer/shop; you may be able to get another several years out of it.... The damage done by discharging too low will be reduced amp-hour availability and reduced service life.
 
Setting a brand debate aside. 3 individual batteries may be easier to haul in and out of an engine bay, then 1 large. 3 may be easier to find a spot in the engine bay then one large. So these are things that need to ba taken into consideration.

Ah wise, barring any issues above, the setup that offers the best Ah x $$, is the best setup. With that said, A group 29 or 31 have about the same footprint as a 27, but a little higher AH. So three 29 or 31 in parallel, could easily be better that 300 Ah.

The cabling to link 2 extra batteries, and the hold-downs, it negligible, unless you have to spread the the batteries out around the engine bay. But, in that case, it sounds like the 8D would not fit either.

Good points - here's a follow up that's a little more specific to Mike's case. He already has an 8D installed. If we get rid of the Ah variable and for sake of argument say his option is to install (3) DC's that equal the (1) 8D in terms of Ah... would there by any benefits from a "use" standpoint - forget about moving them around or space requirements for the extra 2 batteries. Which option, in day-to-use, would be best for him? To me, it seems like 1 battery keeps things simpler? And although the (3) batteries are basically one "bank", I gotta think that one battery still charges better than multiple individual batteries? I mean, in "theory", the 3 batteries should work/charge just as well... but in real-world use?
 
For me its all about capacity and convenience. 3 group 31's have 30% more capacity with a slightly larger footprint. Secondly, I can lift 31's with one hand if need be. Not gonna happen with a 8D. I personally have never had any charging issue with multi batts in parallel. I get the premise though. If its a straight swap and easy to get at nothing wrong with a 8D. It is better than 2 singles.
 

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