Argo diode battery isolators

[foobie]

I've obtained 4 -Deko Promaster 6v 230 amp golf cart batts, but they are a tad used... methinks they are still workable for some time though. I have a 40 watt solar panel with two more 80 watt panels on the way over the winter for lots of charge on the mooring ball...  I wanted to add two new batts and a separate starter batt as well... but obviously I don't want to drag down the new kids to the olders level. What do you all think of a solution like the isolator below? Also - any ideas on how to run two house banks and a starter bank. So far the only switch I am aware of is the 1-2-B and I haven't seen a drawing of that set up the site... apologies if I missed it.

Thanks!

Steve
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Argo diode battery isolators allow multiple batteries to charge simultaneously from one alternator while still maintaining separate battery bank isolation. This protects fully charged battery banks from discharging to depleted batteries yet still allowing incoming charge current. This is achieved by diodes that function as a gate between the banks. Battery isolation is important in marine, RV and generator wiring plans, to prevent household/accessory battery banks from depleting the starter battery.
Argo battery isolators achieve minimal voltage loss by using super efficient Schottky diodes. This means higher voltage output to charge batteries as close as possible to 100%. The voltage drop is 0.3VDC at low current draw and only 0.45VDC at rated output. All models are further fitted with a compensation diode to slightly increase alternator output voltage.

[Steve W10]

Hey Steve,

Have you checked out the "101" on electrical?  Looks like MaineSail addessed solar panel installation and I think there are others that may apply.
http://c34.org/bbs/index.php/topic,6437.0.html

If those articles are still not what you are looking for then....

If I understand you correctly, bottom line is that you'd like to have your start battery and two individual house banks charged off the alternator and/or solar.

A more detailed description of what equipment you have and what you want to achieve may help some of the smarter guys on the forum give you the best advice.

I suspect the biggest things would be...
Do you use a shorecharger at all?   What type? (1 output, 2, 3?)
How 'bout Battery Monitoring?  Want it?

Wiring diagrams rule!

Steve

[2ndwish]

Steve- To work properly, the regulator voltage sense from the alternator has to be connected to isolator compensation diode terminal. If it is not connected, the 0.3 volt drop across the diodes will seriously compromise the charging efficiency and ultimately battery lifetime.

[mainesail]

I've obtained 4 -Deko Promaster 6v 230 amp golf cart batts, but they are a tad used... methinks they are still workable for some time though. I have a 40 watt solar panel with two more 80 watt panels on the way over the winter for lots of charge on the mooring ball...  I wanted to add two new batts and a separate starter batt as well... but obviously I don't want to drag down the new kids to the olders level. What do you all think of a solution like the isolator below? Also - any ideas on how to run two house banks and a starter bank. So far the only switch I am aware of is the 1-2-B and I haven't seen a drawing of that set up the site... apologies if I missed it.

Thanks!

Steve
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Steve,

#1 Diode isolators are like Dinosaur Saddles there's no need for them and there are far better technologies for battery management available today. An automatic combining relay or Echo Charger for a start bank are far better solutions. diode isolators have more issues than just the voltage drop to contend with such as trying to utilize them with solar or modern battery chargers that need a "sense" voltage in order to turn on. There are reasons why no reputable electrical systems guys install them any more.. If you still decide to buy one I have an old Seagull outboard & some baggy wrinkles I can sell you so you can stay with the whole "antique" theme...

#2 If you already have 450Ah's =/- why is there a need for roughly 675 Ah's on a 34 footer? Our boat went around the world on a 250Ah bank a 50A dumb regulated alternator and a single 80W solar panel. Nothing wrong with a big bank at all, when "properly installed", but your choices given would be less than ideal..

#3 By using two separate and smaller house banks you lose all the benefits of one large bank and the shallower discharges and cycling associated with having one large bank. Breaking a house bank into two separate banks yields little "benefit" overall and leads to shorter cycle life..

#4 By adding new batteries to old batteries the banks will have different capacities and the new batteries will not see as long a cycle life as if you started with all new batteries. That said, I would much rather see one large bank, even if old and new are combined, plus one start/reserve bank than three banks. If this is a necessary upgrade then combining new and old would be the lesser or two evils..

#5 My suggestion would be to wire this up as two banks and use your four 6V batts until they die. At that point you can convert to 6 6V batts, if you still feel it is necessary. If you feel you must have the 675Ah's then combine all batteries into one bank and accept the shorter life from the two new ones. $170.00 in batteries that may last three years +/- less is really not a huge loss nor huge expense in the whole scheme of things. Wiring in a full third bank will get far more costly that the losses in cycle life of the two "new" batteries.

#6 Before adding the new batteries be sure to check the specific gravity of the old bank to make sure they are still "balanced". I woudl then do an equalization cycle before bringing the two new ones on-line with them.

#7 If you have not already GET YOURSELF A BATTERY MONITOR before doing any of these upgrade so you know what your actual use and charging capabilities are. I see a lot of money wasted based on "theoretical" use. The $180.00 is well worth it.

[foobie]

Thanks Mainesail!

As it turns out one of my "lightly used" batts was split open and would have been leaking... but it was the only one I didn't check for fluid of course. Alas the perils of Craigslist. So I will definitely reconsider my total power requirements regardless! I was going for overkill in the house banks as we will be on a mooring and wanted to have lots of Ahs for the family. I never had problems on my prev C34, but I was a bachelor then!

I have a new Xantrex Inverter/Charger with a battery level indicator, but will look for a better one. We are on a tight budget at the moment. Any ideas on something that will be workable for less than the $180 range?

I will print your diagrams and bring them to the boat this weekend for a little self-teaching.

Top Notch! Thanks!

[Stu Jackson]

Steve, easiest battery monitor:  from the "101 Topics - Electrical 101"

How to Wire a Battery Monitor by Maine Sail:  http://forums.catalina.sailboatowners.com/showthread.php?t=125606

Within your budget.