Electrical Repair Works on the Yacht

[mitiempo]

Originally Posted by StuM

First place I looked at Trojan:

Trojan SCS200 12V Deep Cycle Battery - Superior Cycling Series

The Trojan SCS200 is the size of a group 31 battery, not a group 27.

While there are a few group 27 batteries with AH's in the 110 range, most are 85 to 90 AH.

The SCS series from Trojan, the most popular being the SCS225, are probably the closest you can get to a true deep cycle battery in an affordable 12 volt battery. They still have less than half the cycles (300) of the 6 volt T-105 at 754.

[mitiempo]

Originally Posted by ramblinrod

Exactly!

2 x Trojan SCS200 12Vdc batteries, connected in parallel, deliver 12Vdc and have a capacity of 2 x 115 = 230 Ahrs.

In comparison, 2 x the 6Vdc batteries that mitiempo sells, connected in series, deliver 12Vdc and have a capacity of 1 x 242 Ahrs.

This is only a 5% increase in capacity. For this marginal gain, one has to change out the wiring, boxes, and live with having to take out 2 batteries if one fails.

In comparison, if rather than incurring the cost of converting from 12Vdc to 6Vdc, one simply added another 12Vdc battery, connectors and box (for less cost than the conversion), they would increase capacity by 115 Ahrs, or 50%. That is a significant improvement and in my mind, much better value for money spent.

Except for longevity which adds up to a much lower cost per AH used over their life.

[StuM]

Originally Posted by mitiempo

The Trojan SCS200 is the size of a group 31 battery, not a group 27.

That's strange, because Trojan says it's 27:

Trojan SCS200 12V Deep Cycle Battery - Superior Cycling Series

[mitiempo]

Originally Posted by StuM

That's strange, because Trojan says it's 27:

Trojan SCS200 12V Deep Cycle Battery - Superior Cycling Series

It is almost 1" longer than a group 27 - the length of a group 31.

[mitiempo]

Another way to compare batteries is weight. The majority of weight in any battery is the lead. When you compare a 3 cell 6 volt battery that weighs 66 lbs to a group 27 that weighs about 50 pounds but has twice as many cells it is pretty obvious that there is more lead per cell in the 6 volt. The thicker the plates are the longer they will last.

[wooden head]

Originally Posted by Tikka

, perhaps you talking about engine alternator, any spare car parts outlet, simply all car alternators have build in regulator, just match the amperage depends how many batteries you intend to install. And finnaly all wiring on the boat is done by " thinned copper wire " from any electrical place. That's is my 40 electr. exp...hope it might help..

DO NOT use automotive alternator. Marine electrical is shielded from spark ignition automotive is not. If you have a fuel leak of any sort petrol, propane...and you dont run your blower or have an air flow issue the insurance deductible or rejected claim on a blown up boat will be more than you save. I don't know if there is also better salt air corrosion protection. As to tinned wire be sure to use propper marine grade tinned wire. Fires or even shorts at sea or behind that hard to get at bulkhead are not worth the savings on cheap wire.
I highly recomend getting and reading Nigel Caulder's book on wiring and mechanical systems.

[Badsanta]

This is like an anchor discussion. Yes both are better and both will fail from bad treatment. I would guess most boat failures of any kind are from niglect. Some take care of their stuff, most don't know how too and don't realize it and think there doing the right thing. Neither will convice the other, and both are right, imoho. But a great discussion anyway.

Sent from my SM-G860P using Cruisers Sailing Forum mobile app

[mitiempo]

Here is a very good explanation of the differences between deep cycle batteries and the other types.

What Is A "Deep Cycle" Battery? Photo Gallery by Compass Marine How To at pbase.com