DC Electrical

Originally the boats were all 32V DC, with a converter for some 12V stuff like engine gauges, radios etc. In the boating world 32V lost to 12/24/48. Kinda like the Betamax and VHS thing. Many people convert to 24VDC. Mine is still in pretty darn good shape though. So there’s lighting, Galleymaid head pumps, water pump, the Ideal anchor winch and a few more things. 8 humongo 8V batteries, 4 in series each side. SB is start only, port is also house bank. Two 32V alternators, starters on the engines and a big charger.

But the bow thruster that the PO installed was new and 24V. So they installed a 24V bank with charger.

And then there was the 12V side. PO also installed a Garmin Nav suite with radar/autopilot and a new AIS VHF. All this is 12V of course. So there were new breakers, switches and another 12V battery. For reasons I’ll never understand they left the old technology Guest charger in place. The thing emitted a LOUD 60HZ buzz which was the reason I wanted it out. But, when I took it out three (!!!) hard wired CO alarms and the Nav systems started screaming that their voltage was low. In fact it was at 9.7VDC. So the battery was in fact not charging and the charger was carrying the entire 12VDC load directly. Closer inspection of the group 31 battery revealed that it was not, as I originally thought, sealed. There were in fact 6 caps, it’s just that they were flush with the top. It took .6 gallons of distilled water. Fortunately it didn’t appear dead dead as after 16 or so hours the charger did go to float charge.

The old beast… (Now relegated to 12VDC power supply in the shop):

New charger with new GFI outlet. Yes needs a cover. On order.

Cables coiled up, but they had 4 nice inline fuse holders in them and shortening the other end would mean opening the thing up. Also not pretty. They are hiding under the air tank quite nicely.


While I was down there tending to the 12V battery I checked the 8VDC ones, and found they were sitting in an inch plus of liquid which turned out to be battery fluid. Fortunately they are in large FRP boxes so the damage was contained. Still it took a few hard hours to clean it up. Slowly mopping it out with paper towels and a set of kitchen tongs, which didn’t look too good afterwards. They just don’t plate things the way they used to…… Access to these is a PITA, especially the SB aft box. Pass the vitamin I. But I got it cleaned up. Checked the levels and found them to be well above the plates. There was a watering bottle down there and I suspect someone over filled them. The 32VDC charger appears to be cycling normally and not putting much more than 8-10 amps in there. Monitoring the situation…..

So then the old Sentry charger started acting up. Rapidly cycling on and off in Auto mode…. Just didn’t trust the thing anymore.

Here is its replacement. Analytic Systems BCA 1000 with the Voltage/Ammeter option. Adjustable for later when (if) I go LiFePO4. I like it. As an aside, that’s quite a few pounds I got out of the port (low) side.

Soooo, for shits and giggles I ran the charger for a few hours until it went into float stage and then I shut it off for the night. In the morning the SB bank was showing a healthy 36VDC, but the Port one was showing 32VDC, and couldn’t drive the head pump. Cick-click on the relay was all I got.

Long story short I ended up disconnecting the 4 batteries and measuring voltage on each. 3 of them came in at 9.XVDC, one was at 6.XVDC Hooked them back up, looked in the cells, and three were bubbling happily while one was looking like a dead aquarium. Bad cell.

Oh boy. So these were Deka 8V195 batteries. 1000+ cranking amps. Not sure of it’s reserve capacity but an educated guess is just this side of 200Ah@20A Then came the bad news: This battery is no longer made. I was hoping to get one, even though one should replace all 4, but I just wanted to buy some time to work on the great plan. (Think LiFePO4)

Deka made a replacement the 819 which at 24.5″ would JUST fit in the boxes. One big heavy mother. And less than 600CCA. WTH? Over $500 a pop, so north of two grand. Ouch. The other battery a lot of Hatt owners were dropping in was the Rolls 8 HHG 21P Beautiful battery with better than 1000CCA and a 20 hour reserve rate at 230Ah, 11.5A Not bad. But oy, big and 120 pounds. Getting the old lugs up and out was one thing, but getting new ones in was another. Then I found the Rolls 8 FS GC HC. While technically a golf cart (deep cycle) battery, it did list a CCA of 586 at 32ºF. Some people get all excited when you use a deep cycle for starting but if you have enough CCA it shouldn’t matter. These batteries are just over 10″x7″ which meant I could put 4 in each box in series to make 32, and the two boxes in parallel to make 1160CCA, and have a 15 hour reserve of 180×2=360 at 11A which is 360×32=11520W, 50% discharge rate is 5760W…. plenty for a night on the hook with some lights, TV, water pump and flushing toilets. And last but not least they were $169×8=$1352 versus $1600 for the big ones. Plus some extra cabling of course.

So……. out with the old:

Interestingly they turned out lighter than I thought they would. 90 pounds each. This means 360 pounds verus the 480 of the 8 Rolls… This is not helping my list to Port. But there’s something else in the works there. But it also means there’s a lot more lead in the Rolls, which makes them a better battery! Meanwhile getting the 8 new batteries down and into the hole was work, but manageable. Some quality time making new cables and they are good to go.