Choosing a battery charger

D

dlochner

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Jan 11, 2014
12,777
Sabre 362 113 Fair Haven, NY
Mark Maulden said:
the charger needs to be installed in a ventilated area. I believe there are fans to move air through the chassis…
Click to expand
The Sterling/Pronautic chargers do have a cooling fan. The place @Scott T-Bird is considering is much larger than the place my Pronautic is in. After 7 years mine is still working just fine. From time to time I can hear the fan come on and it will run until the charger reaches the absorption phase (Pronautic calls it conditioning) and then it stops. Heat has the potential to be an issue with a large bank needing a lot of charging at the bulk stage.

The Promariner will shut down if the ambient temperature rises too high. This from the Promariner Manual:

Generally this indicates that the unit has been installed in an area with a very high ambient temperature. This unit is designed for use in an engine room, if installed in an engine compartment; ensure that there is proper ventilation in the space for the charger and other temperature sensitive components. If the installation area temperature is 45° C (113° F) or more, move charger or add ventilation to lower ambient temperature. The recommended maximum ambient temperature for installation is 45° C. (113° F)

I think you'll be fine with the charger under the v-berth.
 
J

JohnShannon

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Jan 4, 2010
1,037
Farr 30 San Francisco
Why do you believe 4AWG is inadequate for 60A? My wire tables indicate 4AWG is OK for 60A for power transmission and 135A for chassis wiring. If the issue is voltage drop, the answer could be remote sensing of the battery. Probably need to read the manual of the proposed new charger. Also move the charger as close to the battery as you can, the currents on the 120V side are 1/10th the currents on the 12V sider ( roughly)
 
Scott T-Bird

Scott T-Bird

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Oct 26, 2008
6,243
Catalina 320 Barnegat, NJ
JohnShannon said:
Why do you believe 4AWG is inadequate for 60A? My wire tables indicate 4AWG is OK for 60A for power transmission and 135A for chassis wiring. If the issue is voltage drop, the answer could be remote sensing of the battery. Probably need to read the manual of the proposed new charger. Also move the charger as close to the battery as you can, the currents on the 120V side are 1/10th the currents on the 12V sider ( roughly)
Click to expand
Hi @JohnShannon ,
I'm going by the Sterling manual that has a chart with cable sizes for each model. The problem is the length to the batteries from the original installation, which is close to 40' round trip. I would be limited to the 20 amp model at that length (probably - 40' is off the chart!). I can use 4 AWG cable with the new location because the charger will be much closer to the batteries - easily within 20' round trip. I'll have to increase the AC wires to 12 AWG, but it's not a problem fishing the wires to the new location and it's also not a problem installing the DC cables to the pos & neg busses (just one bulkhead to pass thru).

I was fixated on the original location until I realized I have a better location if I just move a few articles around.
 
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J

JohnShannon

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Jan 4, 2010
1,037
Farr 30 San Francisco
The currents on the AC side are 1/10th of the currents on the DC side. A 40A charger is about 500W I doubt you need 12AWG to support that. In houses it looks like 15A circuits are wired with 14AWG ( 1800W) . But it is your boat and thicker won't be worse.
 
Scott T-Bird

Scott T-Bird

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Oct 26, 2008
6,243
Catalina 320 Barnegat, NJ
JohnShannon said:
The currents on the AC side are 1/10th of the currents on the DC side. A 40A charger is about 500W I doubt you need 12AWG to support that. In houses it looks like 15A circuits are wired with 14AWG ( 1800W) . But it is your boat and thicker won't be worse.
Click to expand
Yes, the chart shows 14 AWG for a 40 amp charger. I'm planning 50 minimum but most likely 60 amp. I'm just going by the chart that Sterling puts in their manual.
 
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jviss

jviss

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Feb 5, 2004
7,089
Tartan 3800 20 Westport, MA
Sizing the charger can be done according to your use case. How are you using your boat and batteries? It should be able to keep up with your electricity use and keep the batteries up; not instantaneously, just over a day or so. When you come back to the dock with some depletion, how fast do you need the batts to come all the way back up?

What do the batteries need for good health?
 
Maine Sail

Maine Sail

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Feb 6, 1998
11,701
Canadian Sailcraft 36T Casco Bay, ME
Scott,
I have a bunch of PCU's left over. Only problem is I can't ship them. If you know anyone in Maine who could pick it up they are a killer deal..
 
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Scott T-Bird

Scott T-Bird

.
Oct 26, 2008
6,243
Catalina 320 Barnegat, NJ
Stu Jackson said:
Why?
Why not use the handy BlueSeas wiring sizing chart?
Wire Sizing Tables from West Marine (unfortunately they removed the handy charts! around 2016) Marine Wire Size and Ampacity | West Marine www.bluesea.com also has good material on this and fusing, but it's a PDF download and doesn't link. Here's the link to the page, scroll down for the PDF download of the
Protect Your Boat With The Correct Size Wire And Fuse - Wire Size Chart
Click to expand
Yep, I looked at the Blue Sea Chart, too (I always go to that one first), and it pretty much yields the same results based on 3% voltage drop. The nice thing about the Blue Sea chart is that it carries out for longer lengths. I can use 4 AWG for my new location where it isn't adequate for the 60 amp charger at the original location. The new round trip will be far less than 20'.
 
Maine Sail

Maine Sail

.
Feb 6, 1998
11,701
Canadian Sailcraft 36T Casco Bay, ME
jviss said:
From the Sterling PCU manual:

"Advantages of this product
...
6) Remote battery sense compensate for cable voltage drop.
Click to expand
The Sterling PCU does not have remote volt sense but the optional"battery Chemistry module" does..
 
Scott T-Bird

Scott T-Bird

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Oct 26, 2008
6,243
Catalina 320 Barnegat, NJ
Maine Sail said:
Scott,
I have a bunch of PCU's left over. Only problem is I can't ship them. If you know anyone in Maine who could pick it up they are a killer deal..
Click to expand
I really appreciate that! @Ward H ... road trip? I did have a friend go to Maine last October .... I'll see if there is anybody I know with travel plans. It is a good time to go to Sunday River.
 
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