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Old 11-01-2011, 09:02 AM   #21
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RE: How big of a charger do I need?

I think you might be mixing 12V apples and 110V oranges here. The charger output of 75 amps is at 12V (900W). Due to inefficiencies, the 110V input to provide this power would be in the neighborhood of 10A/1100W. So even the smallest generators can provide the juice to run the charger. Heck, even my Honda 2000 could easily do it. Add AC and water heater and other 110V loads all at once and you might find 4500W isn't enough. But if you alternate your use of high draw items, a small generator could be sufficient or even preferred. (less W=less noise=less fuel)
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Old 11-01-2011, 10:42 AM   #22
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How big of a charger do I need?

No, I get it, Al. ;-) I understand that 75 Amp output at 12V is not 75 Amps of AC draw on the genset. It's a NextGen 3.5KW (~32A). My concern is not just the water heater.I can turn it off and heat the water with the Perkins if I need to. I am looking at microwave, toaster oven, and stove. I suppose I just need to have some situational awareness while at anchor, but I had not done the math on how long the recovery would be. TBH, I still don't understand the aH math completely (and I have a degree in this stuff). So maybe the 70A might be a better idea even though it can draw as much as 18A at full load. One use of the microwave or stove will pop the breaker if the water heater is heating.


-- Edited by GonzoF1 on Tuesday 1st of November 2011 10:43:26 AM
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Old 11-01-2011, 11:48 AM   #23
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RE: How big of a charger do I need?

That's the beauty of a properly set up battery monitor. It'll do the math for you. If you want it simple, it's about as easy as reading a fuel gage. If you want more details about your batteries, it's right there for you, too.

Have you ever used a kill-a-watt meter on your appliances? It gives you a direct real time indication of the actual load each appliance draws. If you don't have a battery monitor, it's a great tool for determining battery loads and battery bank size requirements. They cost about $20-25 at a local home supply or electronics big box store.
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Old 11-29-2011, 06:17 AM   #24
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RE: How big of a charger do I need?

my small mircowave running tru the inverter uses 100amps dc but of course I never run it that long
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Old 11-30-2011, 04:50 AM   #25
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RE: How big of a charger do I need?

Because of all the losses inolved a simple concept is to multiply the AC units amp draw by 10, and it will give the DC amps required.

Not exact , but close enough.
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Old 12-22-2011, 03:00 PM   #26
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RE: How big of a charger do I need?

Gonzo, I can relate to your concerns about charger sizing and whether to isolate the windlass, etc. When reconfiguring my boat I followed this scenario:

If your housebank is 660AH (wet cell) the recommendation from my battery maker (Dyno, Seattle) is*not to recharge at greater than 10% of capacity.*Wet cell batteries*live longer when charged slowly and*often. Here are*two options for charging: go with a 75amp IOTA/DLS charger*for the housebank and a separate inverter;*OR, install a combined marine inverter/charger (I have the Outback: 2000 watt inverter /*80 amp charger). Install the Balmar Duo-Charge to manage and combine charging needs for both house and start*batteries...these work great at keeping the start bank fully charged, whether on the*hook, underway, or at the dock.

On Northstar, I have a separate*30amp IOTA/DLS*charger dedicated to*windlass battery (mine is a an 8D wet cell). The IOTA*is plugged into*the ships*AC system. I*monitor voltage with an inexpensive voltmeter located near this charger.

A few more items to consider: if you choose wet cell (most value for the money), invest in a handy automated watering system (*http://www.janwp.com/*) I installed one of these on my 980AH housebank and a seperate one for the windlass battery (hard to reach) and now routine maintenace takes minutes! A final consideration is how to recharge while at anchor? If you have an onboard genset, then you're good to go. I removed my tired*genny and replaced it with the*large housebank...but still need to recharge after a while. So last summer I used a Honda EU2000 generator. It proved to be*too small for the job and ran loud and consumed too much gas. (Whatever charger you select, check to see how many amps AC it takes to run. For example, my charger pulled 12 amps AC and the little Honda*was rated at 13.3)*This season I will be using a 12VDC generator (Honda powered) that can produce up to 120 amp DC*directly into the battery bank. Like my excellent Outback inverter/charger, the ALTEN charger originated in Australia for off-grid applications. http://www.alten-dc.com/*

One final point -- don't skimp on new battery cables. I went with heavy duty 2/0 marine grade cable for everything. Good luck with the upgrade.
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Old 12-22-2011, 03:22 PM   #27
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How big of a charger do I need?

Thanks Richard,

RickB and I are well on our way to nailing down the final config and shopping list. I have bought the inverter (TruePower 2000), Duo Charger, and just ordered the charger this morning. I ended up with the Iota DLS55/IQ4. The cabling is where I am a bit stuck. I was hoping to order most of it from Defender in one lump, but in order to get only the amount I want, I am going to West Marine and make them price match. My big hang-up right now is the crimp tool for the lugs is about $250 for a good one. Sheesh... That is hard to swallow. Guess I'll ask around here to see if someone has one I can borrow or rent.

Tom-


-- Edited by GonzoF1 on Thursday 22nd of December 2011 04:23:15 PM
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Old 12-22-2011, 04:37 PM   #28
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RE: How big of a charger do I need?

I found a great USA made crimper on ebay for around $100.

Others say the hydraulic crimper at the chinese store(harbor freight) does a good job, although you have to select the next size down I think for the crimp bit. I don't personally know about this tool, but for $50 with the dies, it may be worth the risk.

Make a couple of crimps, then saw the barrel and see how well the connection is.

good luck
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Old 12-22-2011, 05:20 PM   #29
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RE: How big of a charger do I need?

ithink west marine will let you use theirs or rent it to you
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Old 12-22-2011, 06:27 PM   #30
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RE: How big of a charger do I need?

Best cable and connector prices = GenuineDealz

Best value in crimper = Harbor Freight Tools
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Old 12-22-2011, 07:50 PM   #31
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RE: How big of a charger do I need?

Hey... Thanks y'all !!!!
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Old 12-23-2011, 04:07 AM   #32
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RE: How big of a charger do I need?

My big hang-up right now is the crimp tool for the lugs is about $250 for a good one. Sheesh..

NO where near as fast , but many sized heavy wire ends can be crimped on with a nicro press tool. $30 bucks or so .

I have seen "budget boaters" use a nicro press tool with copper tubing installed , flattened and then a suitable hole drilled in the flat to create an inexpensive cable end.
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Old 12-24-2011, 06:35 PM   #33
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RE: How big of a charger do I need?

Take a look at this page:

http://www.pbase.com/mainecruising/battery_cables

*and read the description of the H.D. crimper for about 140.00.* If I didn't already have* good, H.D. crimper I would go for the non ratcheting version at the page bottom.** Also if you look around the site a bit he has some good points about the lugs themselves plus other stuff electrical.
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Old 12-26-2011, 12:55 PM   #34
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RE: How big of a charger do I need?

Quote:
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My big hang-up right now is the crimp tool for the lugs is about $250 for a good one. Sheesh..

NO where near as fast , but many sized heavy wire ends can be crimped on with a nicro press tool. $30 bucks or so .

I have seen "budget boaters" use a nicro press tool with copper tubing installed , flattened and then a suitable hole drilled in the flat to create an inexpensive cable end.


I just rented a cordless hydraulic/electric one for a day. Made things really easy.
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Old 01-06-2012, 05:36 PM   #35
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How big of a charger do I need?

Speaking of battery cables--- Can a copper lug be soldered on instead of crimped?*** Just curious?

JohnP


-- Edited by JohnP on Friday 6th of January 2012 06:36:27 PM
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Old 01-06-2012, 05:45 PM   #36
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How big of a charger do I need?

No, it needs to be mechanically crimped. Solder-only connections are strictly verbotten. You can solder it first, then crimp it, but it's kind of a belt and suspenders approach and the crimp can compromise the solder connection.


-- Edited by FlyWright on Friday 6th of January 2012 06:46:07 PM
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Old 01-06-2012, 05:50 PM   #37
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RE: How big of a charger do I need?

Quote:
FlyWright wrote:
No, it needs to be mechanically crimped. Solder-only connections are strictly verbotten. You can solder it first, then crimp it, but it's kind of a belt and suspenders approach and the crimp can compromise the solder connection.


Very interesting--Thanks for the input.

I was thinking of changing the location of my Batts and perhaps shortening cables, now I may use the cables as they are.**

JohnP
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Old 01-06-2012, 10:28 PM   #38
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How big of a charger do I need?

The lug should be crimped FIRST, then filled with solder, NOT the other way around.


-- Edited by C lectric on Friday 6th of January 2012 11:46:18 PM
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Old 01-07-2012, 04:20 AM   #39
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RE: How big of a charger do I need?

"then filled with solder,"

The easy way with thick cables is to dip the terminal end in a pool of melted solder.

A propane torch is fine as a heat source.
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Old 01-07-2012, 07:00 PM   #40
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RE: How big of a charger do I need?

I would think one would tin the end of the stripped cable first.

Tinning is applying flux and melting sold onto the bare copper.

Than flux again and inside the lug.* Crimp it on and solder it full.

To me this would be a very positive connection,* little chance of corrosion.

JohnP**** Any opinions?
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