36 Volt In Place Of 32V?

[Brian Degulis]

Many years ago we did some work on a 70' steel comercial trawler this boat had only a 32V DC system with very few electrical acessories. The entire system was shot batteries charger etc all bad. What we did was replace the 8V batteries with three 12V 8D batteries and three 12V battery chargers one for each battery. So we created a 36V system to replace the 32V the chargers were always on so I'm not sure how it would work with alternator charging only it might not bring the batteries all the way up? All of the lights and motors seemed to tolerate the aditional voltage with no problem. One of the advantages I see to this is that you would no longer need a seperate 12V system for electronics etc. With the individual chargers you could tap the 12v off the grounded 12V battery. Also you no longer expensive and hard to find 8V batteries and a 32V charger. I did this about 20 years ago and can't speak for the longevity of it the boat left for Shrilanka shortly after we were done. My 61' MY is 32V and I'm facing some of the problems you guys are talking about and I would be real curious as to your thoughts on this aproach.

Brian

[MikeP]

I haven't found any of the 32V stuff to be particularly hard to find. I don't think it would be worth the trouble to try to convert. Hatts came oem with voltage reducers (32-12) for the electronics so there is no advantage to going to 36V for that purpose. The 32v charging system would not charge the 36v batts properly so you'd have to revise that. Also the 36v system would be too much voltage for any retained 32v items.

IMHO there is nothing to be gained by this and a LOT of money to be spent.

[SKYCHENEY]

IF you were going to convert a 32v system to another voltage, 36v would be the cheapest way to go, but it would still not be cheap. At least with 36v (vs 24v or 12v), you would not have to change wire sizes, but you would still have to get all new starters and alternators and chargers. Also, new bulbs and converters and volt gauges.

Why spend that kind of money when you can still buy all of the 32v stuff? It is not as readily available and you will pay a little more, but that price is substancially less than the cost to convert the whole system.

You cannot just throw 3-12v batts in there to replace the 4-8v ones. They will not get charged completely and they will not last. If you do charge them completely, you could have as much as 48v and that will not run a 32v blower for long without burning it up.

[Brian Degulis]

OK First I'm not sugesting the posability of doing this unless your looking at tired batteries and an old charger. To the best of my knowledge the 32V chargers available today are very expensive and even the new ones are out dated and the 8V batteries are more difcult to find and more expensive. I'm also not sugesting changing all the 32V loads I'm sugesting running them on 36V That's about 1.5 percent higher. The starters and larger motors will definetly handle that. Smaller motors and lights I think would but I'm not sure. And the alternators would proubably need to have the regulators turned up or replaced to get a higher output voltage. Like I said we did this to a simple boat and it apeared to work great.

[SKYCHENEY]

A fully charged 32v system is about 34-36volts. A fully charged 36volt system is 40-42v. Thats 20% more voltage. And if your charger periodically de-sulfates by overcharging, you could have as much as 46-48v for a short period of time. This would mean replacing all of the 32v loads with equipment rated for the higher voltage. If you didn't do it right away, you would be doing it incrementally as each piece failed.

I'm not saying that it wouldn't work. But it would be costly. Then I still would not tap 12v off of a 36v bank. You will cause one battery to need more charge than the others and may "cook" the other 2 upon charging. The only way to do this is with a converter or an equalizer. Read Calders chapter on this. He even writes about driving a nail through the case on a 32v system to obtain 12v (which has been done, but he recommends against it just as he does with any other tap of lesser voltage than the whole).

Instead of spending that much money on a complete change, buy some 8v Rolls batteries and a good charger. That should last another 15 years and by then you can reevaluate the situtation.

[Spellbound]

Brian -- check your PM's

[Trojan]

You could easily convert to the 36 volts with very little trouble. Every thing that ran on 32V could run on the 36V. The only change would be the alternators and chargers. Both charge rates could be set to charge at a lesser rate. Some light bulbs might die a little sooner. But that's a cheap upgrade to 36 when it happens. If you found some long run fans or motor that you though ran on the warm side you could add a small resister. But that's unlikely. No big deal. I would not hesitate to convert if I was in the position where I needed a new expensive charger and batteries. 32 volts was is a stupid design to go to anyway. That was just as bad as 6V cars. I changed all my old 6V boats, cars and farm equipment to 12 volt and never changed a starter and that's a 6v change. I would not change it just because you wanted to. I would need a good reason.


BILL

[Brian Degulis]

Then I still would not tap 12v off of a 36v bank. You will cause one battery to need more charge than the others and may "cook" the other 2 upon charging

That wouldn't true when charging with the individual battery chargers as each battery has it's own charger it would be true when charging with alternators.

The actual increase in voltage from 32 to 36 is 15 percent typically you lose 1V thru isolators so you could bring it down even lower if you wanted to. The bulbs I use in my 32V system are actually rated 34V

I'm not certain about the feasability of just thinking about it

Brian

[Trojan]

They make a divider that you can charge multi batteries from one source. A fully charged system most likely would never sustain a charge level of 42volts. Plus you do not need to charge to that level. A lower level charge at a longer time is better for the batteries. Heat kills, over charging causes heat. My boat charger runs 24/7 on my 4/8ds. I have never added water in 3 years. I will check them again this spring. If your adding water you had better check your charging system. 32v to 36v is completely feasible. It's just a matter of what you are capable of working with. Change can be hard if your not an electrical minded person. What ever works for you.

BILL

[SKYCHENEY]

Okay, before you try it, send a PM to Angela. She had 36v in the boat when she bought it and had to change back to 32v because of all of the problems.

And, after you make the switch, let me know and I'll buy all of your 32v stuff for spares.