Mix 6v and 12v batteries?????

PGIJon

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Mar 3, 2012
856
Hunter 34 Punta Gorda
Is it a problem to use 4 6v flooded Golf cart batteries for the house and a single 12v flooded starting battery? I have a 20A Xantrax Battery charger, which I may upgrade. Thanks. Jon
 
Jan 22, 2008
1,661
Hunter 34 Alameda CA
That's exactly what I have been using for years. Works great. I recommend getting the Profill automatic watering system as well.

We have very low power consumption with only an ElectoScan sanitation device, an led tv and all led lights. We can go almost 4 days without needing any charging. I just got the Balmer Smart gauge to monitor consumption. It is teaching me that the stock alternator doesn't put much back in very quickly.

Allan
 
Jun 4, 2004
1,087
Mainship Piliot 34 Punta Gorda
Yep, that's what I have as well Jon. I recommend a Magnum charger/inverter.
 
Feb 10, 2004
4,096
Hunter 40.5 Warwick, RI
I use 4 golf cart batteries for my house bank and a single 12v starting battery. Never a problem. Just be sure that they are all the same technology - flooded cells.
 
Feb 6, 1998
11,701
Canadian Sailcraft 36T Casco Bay, ME
Provided the charge voltages are the same, or similar, this will not be an issue. It is done all the time..
 
May 7, 2012
1,522
Hunter e33 Maple Bay, BC
Provided the charge voltages are the same, or similar, this will not be an issue. It is done all the time..
I have the identical battery banks ( 4 x 6V + 1 x 12V, all wet cell) with a ProTech1230iPLUS charger. Not high tech nor smart although it claims "Advanced Electronic Fully Automatic, 4-Stage On-Board Battery Charger". The charger has outputs for 3 banks but is wired (jumper) for the 2 banks I have. Here is my concern.

The charger has dip switches to set/program the "Absorption/Conditioning Stage" time for 1,2, 3 or 4 hours. The manual's recommended settings are determined by size and number of batteries, for example 1 - Group 24 = 1 hour, multiple Group 8Ds = 4 hour. The mechanic set the charger for 4 hours during the initial install of the batteries for the new boat (2.5 years ago) . In our case, we have 4 golf cart batteries connected to 1 o/p and 1 Group 24 connected to the 2nd o/p. I expect that both o/p will receive the Absorption Stage for 4 hours. Would that cause any problems for the single Group 24 starter battery? And if yes, then how do you work around the vastly different size battery banks?
 

PGIJon

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Mar 3, 2012
856
Hunter 34 Punta Gorda
Thanks guys! Sounds like the 4 6's and the 1 12 is a plan! I'm also going to go with the Profill automatic watering system.

Hope you are all having a great Thanksgiving! We had some great sailing down here the day before TG! Thanks again!
 
Dec 19, 2006
5,818
Hunter 36 Punta Gorda
Automatic ?????

OK I have to ask and I see the Profill for 2 batteries is around $55 and that is using a hand pump to do the filling so is that the system we are talking about
or something am I missing.
I have had Trojan's T-105"s 4-6 volt and 1 -12 volt since 2011 and love them
and use a Freedom 2000 inverter/charger for charging and solar panels also that do most of the charging.
I use the 12 volt battery as my start battery for the gen and the Yanmar and also have a switch to combine the starter and house bank as emergency just in case the starter battery is not properly charged for some reason.
I don't need to add water that often and even though a auto fill would be nice but it is not that hard to check fluid level and fill if needed and the Trojan web site said to equalize once a month and I don't equalize that often and when I do every 3 or more months and that is when I add distilled water.
Nick
 
Jun 1, 2009
1,822
Hunter 49 toronto
Get the water miser battery caps

OK I have to ask and I see the Profill for 2 batteries is around $55 and that is using a hand pump to do the filling so is that the system we are talking about
or something am I missing.
I have had Trojan's T-105"s 4-6 volt and 1 -12 volt since 2011 and love them
and use a Freedom 2000 inverter/charger for charging and solar panels also that do most of the charging.
I use the 12 volt battery as my start battery for the gen and the Yanmar and also have a switch to combine the starter and house bank as emergency just in case the starter battery is not properly charged for some reason.
I don't need to add water that often and even though a auto fill would be nice but it is not that hard to check fluid level and fill if needed and the Trojan web site said to equalize once a month and I don't equalize that often and when I do every 3 or more months and that is when I add distilled water.
Nick
These work great
You won't need a fill system
 

PGIJon

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Mar 3, 2012
856
Hunter 34 Punta Gorda
Nick... You'll understand when I show you the H34 dungeon where our batteries are located! -Jon
 

Johnb

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Jan 22, 2008
1,456
Hunter 37-cutter Richmond CA
A 12 volt battery is 2 6 volt batteries that share the same case.
 
Dec 19, 2006
5,818
Hunter 36 Punta Gorda
OK

Sorry I guess I forgot about really hard to get at batteries and than guess
the auto fill will really be great.
My bad and I spend $$$$$ all the time and guess it would be quick and no mess
but where I have my batteries in plastic battery box would be a lot of work to
open any way and do spill water any way but not sure they would fit
under covers.
But I guess if I did not need to open anything and just run tube and hand pump
from along side compartment that would be good.
So have seen the video and if it really works like they say and does really work
with out over filling it sounds real good than.
Nick
 
May 19, 2014
19
Hunter 36 Corpus Christi, Tx
actually it's 6 2v batteries in the same case . . . no . . . it's 2.2 volts per cell, sorry
 
Last edited:
May 19, 2014
19
Hunter 36 Corpus Christi, Tx
the big worry about 6v batteries is keeping their orientation exactly the same when reinstalling the batteries; as during other maintenance. The high side 6v battery (+12v) must be return to its prior position and likewise for the low side ('ground'). Switching them is harmful.
 
Feb 26, 2004
22,982
Catalina 34 224 Maple Bay, BC, Canada
Sounds like he's talking about wiring, not locations.

Switching? Got me, too, although one would think no one would want to switch the ^v side, only when as 12Vs.
 
May 19, 2014
19
Hunter 36 Corpus Christi, Tx
Flipping 6v deep cycle batteries.

Looking at this from the battery's point of view; think of them as a line of unbroken cells. As the voltage drops across each cell, the two in the middle see only 6v. Flippin', doubles the potential seen on one 6v side and halves it on the other. That's the problem. New pairs (less than a year) may recover from the stress of an accidental switch. caveat: I have performed this experiment and killed two automotive 6v batteries, switched after 5 years of service.