This is Why I Dropped Out of Electeonics School

Sep 2, 2011
1,041
Hunter 27 Cherubini Alum Creek State Park


It's elementary to understand a simple wiring diagram like this, but I' be always had a mental block as far as how to physically make the connections. In my convoluted brain, it looks like I need to strip a bit of the charger-to-charger wires in the middle and tap in the battery feeds there.
I know that's ridiculous, so what would be the best way to wire my 2 Sterling chargers in parallel? Due to space constraints they will be about 3 ft apart.
Thanks.
 

jviss

.
Feb 5, 2004
6,745
Tartan 3800 20 Westport, MA
I can't see the diagram. Might be my connection. Also, it's electronics, not electeonics. :)
 

jviss

.
Feb 5, 2004
6,745
Tartan 3800 20 Westport, MA
On the topic, are Sterling chargers rated for parallel operation?
 
Jan 11, 2014
11,323
Sabre 362 113 Fair Haven, NY
Why would you want to wire the chargers in parallel? I'm not sure I see the advantage of having 2 chargers on one bank.
 
Sep 2, 2011
1,041
Hunter 27 Cherubini Alum Creek State Park
I can't see the diagram. Might be my connection. Also, it's electronics, not electeonics. :)
Unfortunately, the pic I copied won't paste. It's the only one I can find on the web showing multiple chargers in parallel and without the illustration the post makes no sense. I'd like to jut delete the topic, but can find no option for that.
Really... electronics? Maybe that's why I didn't do good in school.
 
Sep 2, 2011
1,041
Hunter 27 Cherubini Alum Creek State Park
On the topic, are Sterling chargers rated for parallel operation?
I think I remember reading somewhere that the Sterlings could be paralleled, but I'm hoping MS will chime in here since I bought them from him.
 
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Sep 2, 2011
1,041
Hunter 27 Cherubini Alum Creek State Park
Why would you want to wire the chargers in parallel? I'm not sure I see the advantage of having 2 chargers on one bank.
You want your charger to be 10% minimum of the total amp/hrs of your battery. In my case, it's an 840 a/h battery (bank). That would mean a 90 amp charger, and I haven't seen one of those that don't cost bukoo boat bucks and weigh a ton.
So, 2- 60 amp Sterlings gets me 120 amps which is more than adequate. Plus, there's the matter of redundancy
 
Feb 6, 1998
11,667
Canadian Sailcraft 36T Casco Bay, ME
You want your charger to be 10% minimum of the total amp/hrs of your battery. In my case, it's an 840 a/h battery (bank). That would mean a 90 amp charger, and I haven't seen one of those that don't cost bukoo boat bucks and weigh a ton.
So, 2- 60 amp Sterlings gets me 120 amps which is more than adequate. Plus, there's the matter of redundancy

You just wire both chargers into your house banks unswitched positive & negative busbars or use one of these a short distance from the charger outputs then run one set of wires over to the bank.. About a dozen ways to skin that cat..
 
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Sep 2, 2011
1,041
Hunter 27 Cherubini Alum Creek State Park
You just wire both chargers into your house banks unswitched positive & negative busbars or use one of these a short distance from the charger outputs then run one set of wires over to the bank.. About a dozen ways to skin that cat..
But, I thought it was best to run the charger outputs directly to the battery bank - pos to one end and neg to the other.
 
Feb 6, 1998
11,667
Canadian Sailcraft 36T Casco Bay, ME
So then, can I connect the dc + output here at the fuse?

View attachment 140446
#1 Fuse goes at battery end of positive wire not at the charger end. The fuse is to protect the WIRE not the charger... It is protecting the wire from the battery bank not from the charger.

#2
A 60A fuse is way too small for a 60A charger and far too small for 120A of parallel chargers. A 60A charger needs a bare minimum of a 75A fuse and two 60A chargers would need a 150A fuse. Again this goes at the battery end of the circuit within 7" of the + post or distribution bus.

#3
If you bus the two chargers together at the charger end, which is the least expensive and least invasive option, you will need larger wire run over to the bank, from the bus point, because now you have a 120A charger.

#4 The volt drop calcs for a 60A charger will not be sufficient for a 120A charge circuit so the existing cable between battery and charger will be too small.. The wire for the circuit length (pos & neg lengths added together for total circuit length) should be sized for no more than a 3% voltage drop at 120A. 2% is even better.

#5 Get some heat shrink on that lug because if that PL-259 / VHF terminal touches it, it won't be pretty........
 
Sep 2, 2011
1,041
Hunter 27 Cherubini Alum Creek State Park
Thank you RC.

#1. Myself, and I bet a lot of other people, tend to think of electrons as flowing in one direction, away from an output via the pos cable and returning via the neg. with that picture in mind it made sense to protect the wire downstream of the output lug. I'll move it into the battery compartment and replace it with a buss bar. And #2, I'll install a 200 amp fuse.

#3&4. Guess I'll be ordering some more wire and lugs as well. Do you think 1awg would be sufficient?

#5. Look closer, old man, that's clear heatshrink on that lug. (Yeah, I have to take my glasses off and plant my nose on the screen to see it in that pic).

Thanks for all your advice.