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

Bertram indeed used 4x8 volt batteries. Definately have a house bank as well, that way you can parrallel the engine bank with the house bank if it's low. I haven't seen the AGM's last any longer really, but as Pascal said, you don't have to add water every month.

On the 54' Bertram, the house bank is up by the generator and I believe shares double duty as house and gen battery.

You also are going to want a 12 volt bank for electronics mostly. Electronics don't like a lot of noise on the batteries they're using either.

You can't use 3x12 volt batteries because that's 36 volts and they won't charge properly or be fully charged with a 32v system.

I haven't seen AGM's go any longer in a cool location either. I see them last about 6 months longer than lead acid. Generally I see 2-3 years on lead acid, and slightly more on agm. HOWEVER, the really good gel batteries I have seen go at least 6+ years on every boat I've managed...The ones that are grey in color......and most push 8+ years. Most of the newer boats are under-batteried for the size engines they have and that's why the batteries just don't last a long long life..... One boat I manage has 2 8D's to start a C32 CAT for example....that bank of 2 batteries is seriously getting wacked everytime that starter turns over.......I see it on numerous boats.

2 to 3 years is short... I get a good 4 years out of the 8v golf cart batteries on my own boat. Problems that most people don't top them off often enough especially with older ferro chargers

Yeah except your boat has 6-6volt batteries to start a 8v71N, not 2 8D's to turn over a 12 cylinder diesel. In the latter situation you're maxing out the cranking amps of the batteries (almost) everytime you start the engine.

Uh?
I thought Pascal said he had 8v batteries, Figured the same setup I have.
We have some 9 year old flooded 8v batteries still on board mixed in only two banks. The house shares a little from both. They turn over cold 12s fine.
I have one cell out of the Stb 16 that is just getting a lil low on the hydro (3 year old batt). Not a performance issue yet but I check every cell before I check and ad water twice a year. I'm happy with our setup and we live aboard. Lights on-off-on-off countless times every day. Head, shower sumps and blowers are happy. Old Raritan 32vdc charger / converters keep everything up also.
BTW, Just picked a next to new looking matching (two on board already) Raritan 32vdc/40a charger for a spare. $200.00. Looked so good I installed it and am cleaning up the removed charger for storage/spare.

I really don't understand why your ragging old 32vdc stuff.

Because it's getting impossible to find new parts for old 32 vdc stuff. Search for a new 32 volt charger, a bilge blower, and various other parts. Try to convert an old galley made head to a modern head. More and more manufacturers are no longer supporting 32 volt stuff. Forget trying to find it while travelling....... What about lightbulbs and various other things. It's simply being phased out. The only Rule pump you can find in 32 volts is a rule 2000, no other sizes. And, if a guy has a Bertram like the OP and has many 32 volt items that aren't working, it's the perfect time to upgrade. I'm dealing with a 54' Bertram right now that has 60 g IV lightbulbs, they stopped making halogen or xenon G IV lightbulbs 2 years ago in 32 volts...... so $30 LED's rated at 10-36 VDC are the only alternative, except you have to change an entire room or the ones you've changed look REALLY different compared to the others.....The cheaper LED's are only rated to 30 volts........Every part is a mission to source now. What about a 32 volt macerator pump.....etc.....etc.....etc.... the list goes on and on.....and it's only going to get harder.......If you're going to change most items, the logical solution would be to upgrade. Even batteries are hard to source in a lot of area's in 8 volt. The Bertram wiring is large enough and should be fine to go to 24 volts, but at that age even in 32 volts, the wiring is at the end of it's years due to the very large bundles Bertram ran and the heat concentrated in the bundle......30 years is a long time for wiring in a yacht.

Pascal's boat origionally would have had 2 6 battery banks of 6 volt batteries all about the size of an 8D. One shared house and stbd engine, the other port engine........ My comment on batteries not lasting is referring to a lot of the newer boats that are running minimally sized battery banks for very large diesels. Especially the newer computer controlled diesels that are also firing off fuel pumps, injectors, computers and etc when they're starting.

On the electronics;
Most of my stuff works up to 40vdc. My old Robertson IS11 X-box (20 years old) requires 12vdc only. My Simrad AP25/AC40 runs on 24vdc driving a constant running pump that came with the boats original AP1000. Radar, DSM, VHF and more are on a 32vdc buss and don't hickup when any head is used.
I believe most better/newer stuff works over 40vdc. Car stereos (marine? (joke)) still need 12vdc.

I really still don't understand. Received a Rule 800 in 32vdc. New from Canada last month for an A/C sump. Yea, It has some dust on the old cardboard box but for $25 and a couple $ for Canadian post another great deal.
I said earlier in this post and for a long time in others, you shop and stock spares.
On your G4 lamp problem, It's your G4 lamp problem. Yes, some things do change. I don't have 60 blinding bulbs to worry about and can't imagine having 60 blinding lamps to worry about.
But because you have a G4 lamp problem, it does not mean a ships 32vdc system is bad or needs to be replaced in any hurry.

How many do you need?

My 53 is a 32v boat and has two banks made out of four 8v gold cart batteries, 1 per engine and either one being selectable as a house bank. Hatteras later dropped the selector switch

Again a 36v simply doesn't work on a 32v system as the batteries will never be charged properly

The Johnson 70 I run has a pair of 8D AGMs per engine, no problem cranking the 3412Es. Each genset has its 4D and we have 4 8D for house

Vacuflush pumps work on either 24 or 32v according to VF tech and that includes discharge pump

Chargers and inverter chargers are available in 32v although with a smaller selection and a little more $.

The decision to convert is really all about doing the math not worrying about supplies.

Ah ah..


Let me clarify that the original 8v batteries installed by hatteras where significantly larger. A previous owner had switched to the smaller golf cart batteries and i kept them Others have as well

Me neither... The only good thing I see with golf is that those practicing that sport require 10s of thousands of batteries every year which makes them cheaper ironic isn't it how a sports requires batteries

Anyway... 6v Golf cart batteries are around 220AH, 8v about 200AH i think and excellent value. I dont believe they are any cranking amps rating avail since thy are deep cycle batteries

I used to run a 32 volt 58 Hatteras Yachtfish that had 2 vaccuuflush toilets that were installed by vaccuuflush, and they both had newmar voltage stepdown converters installed by Vaccuuflush. This was done back in 2003. But, I don't see how any DC motor will last if you are operating it with a much higher voltage.

If you run a 32 volt motor on 24 volts, it will use a lot more amperage and create a lot more heat in the windings and it will not last nearly as long. If you run a 24 volt pump on 32 volts, it will also turn at a rate faster than it was designed for, taxing it's design parameters, and shortening it's life and will also many times cavitate or airlock and not pump because the impellor will be spinning faster than the body and pump housing were designed to pump as well as the passages were designed for. Not to mention none of the parts will be warrantied by any manufacturer. Not to mention if you run a 24 volt sealand waste pump on 32 volts, it will destroy the bellows in it in rapid fashion. A rule 24 volt bilge pump on 32 volts will cavitate and not pump water, then within a few hours of runnning overheats and melts itself or snaps the shaft off (I tried this once).

Using a 24 volt pump on 32 volts, you're talking about a 40-50% increase in power and speed. Operating a 32 volt pump on 24 volts, is a 40% reduction in power and speed. Way outside of the design parameters of anything.

Just like you don't use 3-12volt batteries on a 32 volt system.

I would not run a 24v pump on a 32v boat unless the manufacturer ok's it

A few hatt owners have been told by sealand that it was ok... (Personally I never had to consider it as all my VF have older 32v pumps). As another example i was told by Shurflo that some of their 24v pumps could be used on 32v, although as it turned out NOT the electronic variable speed. The motor was fine but the electronic circuitry was confused by the higher voltage and they replaced it under warranty with a pressure switch 24v pump

Oh come on, you are smart enough to know that a 36v bank will need voltages of close to 39v to fully charge and that a 32v charger will never get close to that!