Adding a new battery

May 3, 2020
11
Hunter 33 Houston
Hey guys,
I have a '05 33 which currently has two batteries and a xantrex inverter. One battery is a marine deep cycle starting battery and the other is a 100ah battery (house) they are tied into a 1,2 selector.

My question is, how would I add capacity onto the house side? If i put an additional battery in parallel to the house battery would that cause any issues? Would my wiring be straight from the house battery to the new additional battery?
I am overall just not too sure how the inverter/charger comes into play and what it may limit and or how i do things different.

Thanks!
 
Apr 8, 2011
768
Hunter 40 Deale, MD
How old is the house battery, and what kind (e.g. lead acid, AGM, etc.)? What's the charging capacity of your shore charger and your alternator?
 
Jan 4, 2006
6,444
Hunter 310 West Vancouver, B.C.
Wire your new battery in parallel with the original house battery and then treat the combination as if it were a single house battery. This assumes that the two baterries are the same and of similar age.
 
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Likes: Ward H
May 3, 2020
11
Hunter 33 Houston
How old is the house battery, and what kind (e.g. lead acid, AGM, etc.)? What's the charging capacity of your shore charger and your alternator?
Its a flooded battery currently. Its a few years old and I plan to replace it. Just seeing if possible if I grab two to increase my capacity.

My inverter/charger is a Xantrex Marine 10

 

HMT2

.
Mar 20, 2014
899
Hunter 31 828 Shoreacres, TX
Wire your new battery in parallel with the original house battery and then treat the combination as if it were a single house battery. This assumes that the two baterries are the same and of similar age.
What Ralph said, but I would start with two new identical batteries for my hous batt. Also, some care is needed in how you wire them in parallel so that they truly function as one battery. Mainsail talks about it in this article under the heading “Charger Feed Wiring” . Installing a Marine Battery Charger - Marine How To
 
Apr 8, 2011
768
Hunter 40 Deale, MD
+1 on all above. This is definitely something you can do yourself. But do the research on wiring in parallel correctly. HMT2 provided an excellent link.
 
May 3, 2020
11
Hunter 33 Houston
What Ralph said, but I would start with two new identical batteries for my hous batt. Also, some care is needed in how you wire them in parallel so that they truly function as one battery. Mainsail talks about it in this article under the heading “Charger Feed Wiring” . Installing a Marine Battery Charger - Marine How To
Thanks for the link!

Seems the main thing is that the positive and negative from the charger go on separate batteries. I will read up on the article also as I have experience with 12v but once throwing inverter/charger in there, I have no experience
 
May 24, 2004
7,129
CC 30 South Florida
Like Ralph J indicates just wire the new battery in parallel to the House battery. Match the type and size of the new battery to the one you currently have. Failing to match the age and condition of the battery may or may not be of consequence. I never have a problem gambling on the life expectancy of a new battery that costs @ $100 but a mismatch could bring consequences to the life of the battery charger and alternator. If once you add the new battery you see that the charger is working too long to get full charge or boiling the electrolyte water on the batteries I would replace the old battery with another new one. But no need to cross that bridge until you get to it. The usual negative is that the useful life of the new battery will be shortened somewhat. A mismatch is quite common and you can find it in almost every bank even if the batteries bear the same Born Date. The hard part is finding the space for the new battery. Good luck.
 
Jan 5, 2017
143
Hunter 356 SF Bay / Delta
This is what I did... put both of your new batteries on the "1" side of your battery switch. My suggestion would be to consider this your "primary" bank and leave it selected all the time. Keep the starting battery as "2" on your battery switch and think of it as a "reserve" bank.

If you're away from shore power for long periods, you may want to add an ACR with this configuration to keep both banks charged.

Its a flooded battery currently. Its a few years old and I plan to replace it. Just seeing if possible if I grab two to increase my capacity.
 
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Jan 21, 2018
78
Hunter P42 Ft Lauderdale
If you have the room, you may want to consider replacing the house battery with a pair of GC2 golf cart deep cycle batteries. About 220 amp hours and $95 at Costco.
 
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Likes: Ward H
Jan 21, 2018
78
Hunter P42 Ft Lauderdale
Just check the dimensions. The GC2’s are taller than most 12v batteries and weigh 60 pounds each. We use four of these in boat and the RV.
 
Jan 21, 2018
78
Hunter P42 Ft Lauderdale
Sorry for all the posts. This IOS app needs work

Connect the two 6v GC2’s in series: charger + to + on one battery, charger - to - on other battery, and a 2 gauge jumper connecting the remaining two posts (+ & -).
 
May 3, 2020
11
Hunter 33 Houston
Sorry for all the posts. This IOS app needs work

Connect the two 6v GC2’s in series: charger + to + on one battery, charger - to - on other battery, and a 2 gauge jumper connecting the remaining two posts (+ & -).
Thanks ill checkout our space. seems like a reasonable idea given that the other battery on other bank is a 'starting battery'
 
Jan 21, 2018
78
Hunter P42 Ft Lauderdale
Sorry for all the posts. This IOS app needs work

Connect the two 6v GC2’s in series: charger + to + on one battery, charger - to - on other battery, and a 2 gauge jumper connecting the remaining two posts (+ & -).
Thanks ill checkout our space. seems like a reasonable idea given that the other battery on other bank is a 'starting battery'
If you are replacing one battery with two you will want to keep an eye out for a discarded battery to turn in to avoid the second core charge. At Costco and Sams Club there is one core charge (~$15 i think) regardless of battery type/size. At least this has been my experience. Talking to NAPA i discovered their core charge (and refund) varies with the size. A regular 12v is $18 and a GC2 is $27. I imagine a 4D and 8D might be even more.
 
May 3, 2020
11
Hunter 33 Houston
Sorry for all the posts. This IOS app needs work

Connect the two 6v GC2’s in series: charger + to + on one battery, charger - to - on other battery, and a 2 gauge jumper connecting the remaining two posts (+ & -).
what do you get to hold these batteries ?
 

buddy0

.
Sep 17, 2014
48
Hunter 33 Oriental, NC
I recently went through the analysis for upgrading my house bank on my 05 Hunter 33. My first choice was the 6v golf cart batteries, but after much time measuring, I concluded that the height was just too tight to fit safely.

In the end I installed two size 31 true deep cycle batteries for the house bank and nothing for the start bank. I use the house bank to start my Yanmar. For emergencies I have a separate portable start/jump battery pack.

My local Costco doesn't carry the size 31 true deep cycle batteries. I got a similar price at Batteries Plus on Duracell SLI31MDC with a rebate.
This gives me 210 ah for about $230.
 
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Jan 7, 2011
4,723
Oday 322 East Chicago, IN
I recently went through the analysis for upgrading my house bank on my 05 Hunter 33. My first choice was the 6v golf cart batteries, but after much time measuring, I concluded that the height was just too tight to fit safely.

In the end I installed two size 31 true deep cycle batteries for the house bank and nothing for the start bank. I use the house bank to start my Yanmar. For emergencies I have a separate portable start/jump battery pack.

My local Costco doesn't carry the size 31 true deep cycle batteries. I got a similar price at Batteries Plus on Duracell SLI31MDC with a rebate.
This gives me 210 ah for about $230.
Are they wired as 1 bank?

Greg
 

buddy0

.
Sep 17, 2014
48
Hunter 33 Oriental, NC
Hi Greg. Yes I wired them as one bank.
I have nothing on #2 bank now.
I also have solar panels wired into that bank.
 

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