How many batteries?

journey on":3fsgaoae said:
The best battery hasn't been mentioned: 2 golf cart batteries in series.
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You are actually the third to mention 2 golf cart batteries in series in this thread.

I have seen a lot, but never seen this setup firsthand. It seems like a great house setup. What is the downside to this setup? I figure there must be some issue or it would be more common.
 
The downside could be the shape/dimensions of them vs. other sizes and the fact that the are not sealed so cannot live in the cabin of the boat but only in vented "outside" spaces and are not maintenance free.

A set of group 31 12v batteries of similar design provides similar performance in just a different form factor. Cart batteries may be found cheaper in some instances than marine batteries due to unfortunate marketing realities.

They might be better designed for deep, regular discharging, and that could be an advantage if one could prove that is the case when compared to a non-cart battery.

I am a battery in the cabin guy now so they were a non-starter for us.

Greg
 
OK, Katushka/Katherine, here's a photo of how I installed 2 ea golph cart batteries in Journey On, starboard lazerette. there's also a series of pictures showing the port battery and charger installation in Journey On. I built a plastic shield around the port battery to protect the "stuff" in the lazerette from battery acid.

And my mother's name was Katherine, my dad used Katushka.

Golf_Batt_0.jpg

Boris
 
So it sounds to me like my rather empty port lazarette on my 22 might be just right for a couple of these. This has been on my mind lately, and I'm about to pull the boat to do some TLC. Perhaps the battery system will get an upgrade!
 
I would be surprised if a pair of 6v golf cart batteries would fit in a lazarette of a 22. They are pretty tall, and REALLY heavy. I had them on my sailboats and they were great for the power hungry refrigeration.
 
No way Golf cart batteries would fit in one lazarette.

I am a huge fan of golf carts, and ran big banks on my larger boats, and on the RV I am currently in. (for example 6 golf carts in series to give 12 volts, and parallel to give about 675 amp hour capacity--or 338 amp hour usable capacity.

I have to keep brother Boris honest:
The Trojan 105's are 225 amp hours at 20 hour rate (two in series)

Two Trojan XHS group 31's in parallel are 260 amp hours at 20 hour rate. (130 amp hours each) So the two Trojan XHS group 31's win in this comparison. There are other factors--and that is the Golf carts are made with heavier plates, and are going to last better in deeper discharge states.

Also, to clarify, your EU 1000 only charges at 8 amps 12 volts DC--but if it runs the 40 amp charger in your album, it will put out 40 amps.

The other item perhaps debatable, I need to mention--sorry Boris--but you need to have the terminals covered to be in compliance with ABYC regulations. The other issue I would wonder about are the multiple leads off the plus side of the Golf cart: 3 or 4 plus at least 2 large cables? I try and restrict my battery leads to large cable power out to the switch, and the battery charger wired directly to the battery. Also I have an aversion to wing nuts on batteries. I use hex head nuts--with a flat washer, and lock washer. Far tighter, and safer. Also consider anti corrosion spray on the terminals. (Again, this is a "teaching moment". These seem to be wet cell batteries, but not in boxes (although properly tied down). ? material.

Regards.
 
Our Tom Cat 25.5 came with 4 12 volt wet cell battery, all mounted in the stern, (one for each Honda 150, and two for the house), plus a switching system that allowed them to be separated, or combined.

We had several problems with this. 1. In the stern the outboard batteries were difficult to access, which made checking for fluid level a chore. 2. It added more weight aft, which a Tom Cat does not need. 3. It did not provide enough power to stay at anchor for more than a day without running a genset.

A year ago we changed to: A 12 volt dry cell battery for each engine located in the center of the stern. plus two 6 volt dry cell RV type batteries mounted in the closet floor on the port side of the cabin. We also changed all the inside bulbs to LEDs. Have yet to run out of power. Also find boat now better balanced laterally.

We also have two Honda gensets, a 1000 and a 2000. Experience has been the 2000 is probably overkill, a bit too heavy and also quite noisy. lf we carry a genset now, it is only the 1000. An hour in the morning or evening is quite enough for our DC use.

One problem with the 1000, C-Dorys frequently have electrically powered water heater, and the 1000 will not put out enough power to run that unit, whereas the 2000 will.

It is also our habit to isolate the engine batteries from each other, and from the house system every time we stop for any length of time. We wound up moving the switches installed at the factory in the stern, to a more convenient forward facing location to make this easier.

Kevin Ware
El Gato Tomas
Tom Cat 25.5
 
Well, Bob, you make some interesting points. Still, I think that golf cart batteries are the answer to anchoring power, as I mention below.

First, yes, 2 ea 31 RV batteries have more rated power. 2 ea 31's aren't going to fit inside a C-Dory 25 lazerette. And RV batteries will not last as long as golf cart batteries, cause they aren't built the same. That's why you used and I use golf cart batteries. When we lived on board, RV batteries only lasted about 10 mos, even at 50% discharge. I checked and that's what they're rated for. Switched to golf carts and they lasted until I sold the boat. Still, your choice. Golf cart batteries are 1 1/4" taller.

I counted the wires off the battery and I was disgusted. But each needs direct access to the battery and are separately fused. Count them:
1. Power to the main switch, DC boat power.
2. Power to the inverter switch, DC inverter power. Don't mix the 2..
3. Power to the bilge pump.
4. Voltmeter line.
5. To the Wallis, factory installed.
I want to put in battery terminal strips, and I will do this after a few other tasks. Only have 1 return line though.

Sorry about the uncovered terminals. And those batteries are using the factory battery hold downs, suitably reworked. They're not going anywhere, even upside down. To make everybody happy, I use 2 wingnuts and 2 hex nuts. The Supreme Court says we can't discriminate.

You know, I forgot about the DC output of the Honda gen. You're right, that's only 8 amps. Since the Honda puts out 800 watts on the AC side, I assumed that everyone would recognize that i use a regular battery charger, connecting the gen through the shore power input. I lost the DC cable years ago.

And, Kevin, Journey On has the same water heater. Defender sells a 240 VAC heating element. If you install this in the heater, the 1000i gen will heat the water at a 400 watt rate. It'll take longer but you can do this whilst you charge the batteries (after the initial surge is over.)

Boris
 
thataway":6ew3nid3 said:
I use hex head nuts--with a flat washer, and lock washer. Far tighter, and safer.
Click to expand...

I agree Bob. The batteries in my boat currently have hex nuts but the one in my travel trailer has the wing nuts. I always jam a screwdriver between the wings and use that to apply a little extra torque. One thing I don't like about them that might be explained by your use of the word "safer" is that the wings stick out farther and especially if the positive is left uncovered(sorry Boris) it leaves a larger area of bare exposed metal which could cause a short/spark if something errantly touches it.

Regards, Rob
 
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