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Old 16-03-2009, 17:29   #1
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Iota 45 Cable Sizing

My charger arrived with very little documentation. What size wires to the battery have you other Iota guys used?

I'm no expert but it seems 45amp wire is overkill since it spends so little time at full power. The run is going to be very short(2-3ft).
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Old 16-03-2009, 18:01   #2
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How long do you think it would take to overheat undersized wires?

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Old 16-03-2009, 18:09   #3
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I'd use AWG4 wire. That would give you a voltage drop of about 0.1v with a run of 8' (4' each way).

By the way, unlike most chargers, the Iota is capable of putting out full power for quite awhile if your batteries need it. It will hang in there above 40A output if needed. Depends on the state-of-charge of your batteries.

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Old 16-03-2009, 18:19   #4
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http://www.iotaengineering.com/pplib/dlsmanl.pdf

You are right, they don't provide much information.
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Old 16-03-2009, 18:23   #5
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I believe that #4 wire is the biggest that will fit in the Iota chargers. The charger that I purchased two years ago did not meet ABYC standards b/c it only had a compresion screw to hold the #4 wire and not a plate. I don't know if they are still manufactured that way.

I don't know if this was the best idea but I added a little solder to the end of the wire which made it so that it wouldn't splay the wires as much. I tried to compress this while it was still warm so that the shape of the screw would be held in the wire. Great chargers.
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Old 17-03-2009, 07:57   #6
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Quote:
Originally Posted by DeepFrz View Post
http://www.iotaengineering.com/pplib/dlsmanl.pdf

You are right, they don't provide much information.
That is exactly what came with the unit. My guess is that they are packaged for professionals that don't need instructions.

I was hoping to use some #6 battery cable that I have already. Trips to the store are a PITA these days but I guess I'll suck it up. Thanks for the info.
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Old 17-03-2009, 10:39   #7
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Aquaholic:

Looking thru the tables for 50 amps using SAE wire if you have a #6 wire a run of less than 15' is fine . If you are using AWG wire there is an even bigger safety margin. No reason to run to the store the #6 cable should be fine.

Source:
Table 3-5 conductor size for 3% drop in voltage.
Boatwoners Mechanical and Electrical Manual
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Old 17-03-2009, 14:55   #8
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Use a minimum#14 AWG wire on the (12A) 120VAC input, and minimum #10 AWG wire on the (45A) 12VDC output.

Your #6 cable should good for at least a 20' run (10' separtion = 10' pos + 10' neg = 20' cable).

The Iota 45 draws 12 A at 120VAC input, for which #14 is adequate. The (nom.) 12VDC output of 45 Amps requires a minimum current-carrying capacity of 45 Amps (#10AWG). #10AWG wire is suitable (per ABYC, but not per NEC, which would require #8) for an ampacity of 45 Amps, and over a round-trip distance of 6 feet (2 x 3') 270 Amp/Feet A, also requires #10AWG (good to 300 A/Ft) wire to limit Voltage Drop to under 3%. Should the cable run turn out to be longer than6.66 Feet (3.33' pos + 3.33' neg), you will require larger (#8) cable.

See (print & save) the Wire Size Charts:

http://www.cruisersforum.com/gallery...r&imageuser=79

and

http://www.cruisersforum.com/gallery...r&imageuser=79
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Old 17-03-2009, 16:49   #9
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I finished the job earlier with the #6 and the cables didn't get warm at all after charging at 35-45 amps for 2 hours. The charger came with its own input cable/plug.

The old charger had 2 hot wires. One for each battery. I only have one now. If I leave the switch in the 'both' position, its the same as having the bats connected in parallel, right? Does the other battery take longer to charge?
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Old 17-03-2009, 17:37   #10
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Quote:
Does the other battery take longer to charge?
No, as long as there is no appreciable voltage drop across the switch.
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