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Change from 32 volt to 24 volt (or even 12 volt)

Discussion in 'Bertram Yacht' started by Navatech, Apr 7, 2013.

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  1. Navatech

    Navatech New Member

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    Hi, my recently purchased 1985 46'6" Bertram Convertible has the standard (for the time) 32 volt system.

    Has anybody redone a 32 volt to a 24 volt system?
  2. Pascal

    Pascal Senior Member

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    You can't downsize to 12v as the wiring will not be heavy enough. down to 24v has been done but there are really no valid reasons to do so as 32v stuff is not that hard to get and whatever money you re going to save using 24v stuff is going to be offset by the conversion costs.
  3. Navatech

    Navatech New Member

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    The thing is the boat is missing a lot of 32 stuff as it is (Raritan Electra Scans, batteries) and what remains is quite dodgy... IOW, I'm looking at a big job anyway and if I have to spend the time, effort and dough I was thinking I might as well get some additional benefit...

    And no, 32 volt stuff is a PITA to get (if you can even find it as much is unavailable) and it's only going to get worse...
  4. Capt Ralph

    Capt Ralph Senior Member

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    Please look thru my history and find comments on 32vdc systems. 32vdc stuff is not hard to find. A proper inventory of spares like you would on 12vdc stuff keeps the surprises down. I shop and buy allot of new 32vdc stuff on line. The 32vdc system is nothing to be scared of and is very solid. It WILL always be around. You just need to shop and keep spares like you should be doing already.
    Raritan supports 32vdc LetraSan systems easily. I'm about to install another one next week. Never had a problem finding 8vdc batteries (4 in series). Delco starter windings and alternator regulators are on the shelf, My shelf included (Oh, 32vdc starters last forever). 32vdc motors are still available new. If you don't stock any spares, it's just a second day away from most supply outlets. Understandable, high volume shops like West Marine and the like may not not keep much local but it's in the where-house.
    If you need anything, tap on one of us ole Bert & Hat owners. I'm available by PM for anything extra.
  5. RT46

    RT46 Senior Member

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    besides availability of 32V parts and systems, what are the disadvantages and advantages of 32v and 24v vs 12v?
    Fred West likes this.
  6. Capt Ralph

    Capt Ralph Senior Member

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    32vdc, lighter wires. Less current draw. 32vdc on your boat now, reliable and paid for.

    24vdc, going to 24vdc from 32vdc has NO advantages. You may tax marginal sized wires to carry more current. They may get warm and then,,,,. They will get hot if you go to a 12vdc system.

    Remember your amp, volt, resistance rules.

    Find a way to pay for diesel and enjoy your boat. When you have extra diesel, call me.
    Saburke17 likes this.
  7. Capt J

    Capt J Senior Member

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    IT IS NOW. I just came across a 32 volt Bertram. They stopped making G IV lightbulbs in 32 volts 2 years ago. The boat has 60 lightbulbs throughout the interior. The only alternative is 10-36v LED light bulbs at $30 EACH. Jabsco no longer makes the 32 volt bilge blowers, so now you need to buy the blower 24 volts and the 32 volt motor for it seperately and convert it. The list goes on and on. It is now much harder to find anything 32 volt. I would definately switch to 24volts. Granted the only advantage is 32 volt stuff uses 50% less amps than the same 24 volt item. Parts availability with 32 volt systems is coming to a head considering the last boat they built 32 volts was around 1985, and there are less and less 32 volt boats, so manufacturers are not re-producing parts anymore as they go out of stock.

    What needs to be changed to go to 24 volts: Engine Starters and alternators, batteries, toilet pumps, battery chargers, bilge pumps, light bulbs, Other pumps such as macerator pump, shower sump pumps......and whatever else is 32 volts.......but if you need that much stuff, I'd convert. The Bertram wiring should be heavy enough to go to 24 volts, definately NOT 12 volts though.
  8. Capt Ralph

    Capt Ralph Senior Member

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    How many 30200-0020 or 98012-0040 32vdc blower or pump motors do you need. I have a pile collecting dust. One just sold on e-bay for $31.
    Two cases of household screw in 32vdc lamps @ 25 watts. Another case Mixed up-to 50 watts (don't use them often). Bilge pumps, box of nav lamps, box of unused 32 to 12vdc converters. New 21 & 30 SI 32vdc alternators in my shed collecting dust (& rust). Never knew G4 lamps came in 32vdc. G4 LEDs start at $11.95.
    Like I said, shop, stock and don't worry.
    The sky is not falling. But it's your boat, conscious and future. And you have to decide how to protect your investments.

    Chow.
  9. Capt J

    Capt J Senior Member

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    The 10v-30 volt LED's start at $11.95. You can't use them in a 32 volt system. I need 10 giv's for 32 volt.....
  10. Kafue

    Kafue Senior Member

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    Like your attitude!
    I bought a spare 32v Alternator on advice when I bought my 1970 Hatt.
    It has been concerning me regarding the future supply of 32v, especially when I am Downhere! Do need a bilge pump and switch. In fact make that 2, just in case.
    PM me and we can sort out payment and shipping.
    Question also, why did the manufacturers stop using 32v if it has all the stated advantages?
    Cheers,
    Kafue
  11. Capt Ralph

    Capt Ralph Senior Member

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    I'm just not sure.


    I had a surveyor tell me a couple of years ago that the 50 volt (48vdc) stuff was getting more popular. And, last week in an other thread here, a note about VW going to 48vdc and saving a lot of weight in a car.
    Oh well.

    My 10kw radar has to have at least 24vdc and loves 32 like most of my gear.

    Lights don't dim (like on other 12vdc boats) when the head is operated. Old Crown stuff here still running fine. 32vdc Crown base motors in the shed collecting dust also. I have replaced only one head motor in 9 years. Un-noticed base leak soaked the motor.

    It's just before 0600 here. I'll pull up some Rule pumps from the forward hold and get back to you later today. I use the same Rule H D float switch.

    ,rc
  12. Navatech

    Navatech New Member

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    What batteries

    OK, assuming I'm going forward with the existing 32 volt setup, what was the original battery setup on these (1985 46'6" Bertram Convertible) boats?

    16 x 2 volts? 8 x 4 volts? 4 x 8 volts? I think it's the latter as there are (what I think) 2 double boxes on each side of the battery space. Should I keep to the original setup or should I consider something else?

    Also, I assume I should get two banks of those (one bank for each engine)?!...

    What about "house" use? Would that require an additional bank? Where would those batteries have originally been located (I don't recall having seen them but maybe they're still there)?

    Any pointers about what kind of batteries to get? Acid/Gel/AGM?
  13. Pascal

    Pascal Senior Member

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    Four 8V batteries is the standard set up to make up a 32v bank. DO NOT try using 3x12v like some have tried.

    Ideally, you should have a bank for each engine and a house bank. This is by far the best set up although many older hatteras have two bank, one per engine, and one of them used as a house bank. This works fine for most although it depends on how you use the boat. It you anchor out a lot and do not run the genset full time a dedicated house bank is a better option

    AGMs are nice as you don't have to top them off which can be a pita on some boats with limited access to batteries. Personally I m not convinced they are worth twice the money as they dont last much longer than regular lead acids On my boat i use 8volt golf cart batteries which run about $120 a piece and weight about 70 lbs making them easy to install. Four of them have no problem cranking the 8v71ns

    Some folks use Rolls batteries which come in 2v cells and are very durable.

    Standardization must have been part of the switch to 24v but also i think that better accessories incl tinned wiring made it possible to use 24v on larger boats
  14. Fishtigua

    Fishtigua Senior Member

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  15. Navatech

    Navatech New Member

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    Thanks for confirming that.

    Duh! Last time I checked 3x12 volt = 36 volt... I can only wonder "what were they thinking?!..." Another, no less stupid, setup would be 2 x 12 volt plus 1 x 8 volt... Yes, at least in this one the simple math works out but the rest doesn't...

    Actually, as the boat will be used in Florida and the Caribbean so I think it will have the AC working most of the time. That obviously means running the generator most of the time. In fact, I don't recall seeing where the "house" bank was/is(?) located. Possibly it had the same setup as the older Hatteras'. I guess I'll have to research this some more. Most probably the only sure answer will come from studying what's (left) in the boat.

    Twice as much?!... Ouch!... Considering that I have very good access I guess I'll go for cheaper then...

    I have 8V92TI's but that's almost the same engine so I guess what works for you should work for me.

    Rolls batteries come in 2, 4, 8 and 12 volts... How much more durable are they and how big is the premium for this additional durability? Pay twice as much for 3 times the durability is a good deal. Anything below that I would most probably pass on.

    There's more to making a 32 volt wire into a 24 volt wire then just tinning it. With the lower voltage the current goes up requiring thicker wire. I have been told that Bertram used tinned wires as standard and that they regularly installed thicker wire then the bare minimum so possibly I won't have to do a lot of rewiring. I guess I'm going to have consult with a certified marine electrician on this.

    As it looks now I'm IF I decide for a change I'm most likely going to do the change in a gradual manner. If there's no 32 volt "house" bank I'll possibly start with a 24 volt house bank and move stuff from 32 volt to 24 volt as it becomes unavailable.
  16. Navatech

    Navatech New Member

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    Do the math!... 3 x 12 volt = 36 volt... That's 12.5% more then the required...
  17. Capt Ralph

    Capt Ralph Senior Member

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    I ran a cable from the 3rd battery top to the breaker panel. (24vdc). My plan was to slowly tie this strap to a breaker when I converted that circuit to 24vdc. (Nav lights, Blowers, options). That was near 9 years ago. The strap is still unused but in place.
  18. Pascal

    Pascal Senior Member

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    My comment about tinned wiring is that it doenst corrode like bare copper and will not build resistance over time meaning that you can run slightly lower voltage (32 to 24v)

    36v batteries in 32v system will not charge properly... Pretty obviously. Yet I ve seen it... And batteries don't last.

    A friend of mine use the smae batteries with 8v92s. No problem

    I get 4 years out of golf cart batteries. I ve yet to hear anyone getting more than twice that with rolls although maybe it is possible... I ve yet to see AGMs lasting more than 4 ton5 years.

    I have a small 24v auxiliary bank on my boat for electronics and a few things like oil change pump and shower sumps.
  19. Kafue

    Kafue Senior Member

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    Could the heat of the engine room be the reason the AGM's are not as long lasting as expected?
  20. Pascal

    Pascal Senior Member

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    I ve wondered ... But the house bank didn't last much longer although it is not in the ER

    In all fairness we had a charger failure which resulted in deeply discharged batteries, and that may have shortened their life a little.