Wiring in a battery charger with dual batteries.

[SquidMarks]

Hi All, 

After a long hiatus from fishing (and boat maintenance) due to renovations i have come back to do a little upgrading. 

 

I have purchased a CTEK Marine 200 15 amp charger.

 

I have read on the CTEK website that the charger can be permanently mounted to the boats wiring so im trying to do that instead of mucking around with aligator clips trying to connect terminals to each individual battery every time i need to charge.

I am trying to mount the positive and negative terminals of the battery charger to the switch so that i can run the charger when the boat is parked and the battery isolation switch turned to 'off'

My current wiring setup is basically the same as the following image:

 

 

The switch is 4 way (Bat1, Bat 2, Both and Off).

The negative terminal is easy enough to sort out but i can not see a solution for the positive terminal wiring as any attempt to connect both batteries to charge simultaneously will result in both batteries being connected constantly. 

i thought it should be easier than this or am i overlooking something obvious?

Any help would be greatly appreciated!

 

[SquidMarks]

i should mention that i understand i could connect the charger to common on the switch  and then charge with the battery switch set on 'both' but that would also energise the rest of the circuit (which is what im hoping to avoid). 

[raging]

I just use two ctek comfort connects connected to each battery and charge one at a time

[zmk1962]

Hi Squidmarks,

My solution was to run a +ve wire from your switch 1, 2 connectors and a -ve wire from your battery into a multipin plug connector. The other part of the plug connecter is wired into your CTEK charger. That way its a plug and unplug of the multipin connector to connect or disconnect your charging circuit.  Please see attached pictures.

Note:

1) I put a fuse into each of the +ve wires from the switch pole (1,2) to the multi pin plug. 

2) I made the plugs that comes from the switch: +ve  female and -ve male (don't like exposed +ve terminals in a -ve grounded boat !)

3) I have a 3 battery set up. So I used a 4 way multi pin plug connector as pictured so I have 3x +ve and one -ve. But it is analogous to what you are trying to achieve.

4) I have hard mounted the multi pin plug coming out of the switches up high on my transom. You can see it just under the switches facing the camera smothered in good old vaso. You can also see the 3white fuses in the charging circuit in the photo.

Hope this helps.

Cheers

Zoran

[zmk1962]

PS - Wiring no probs....BUT.... I can't for the life of me figure out how to imbed pictures where I want them in the text or how to get the orientation of the pictures correct.  Sorry !

 

[SquidMarks]

Thanks ZMK, 

 

that is pretty much how i was thinking of handling it, except i was hoping to get away with a regular 15amp extention lead plug (male from charger and female from batteries). The problem is, 15 amp plugs dont connect the positives like the anderson plug!

 

I Might need to go the anderson plug route...

[antonywardle]

I put a VSR in mine. It goes between the two batteries, so that when the first one is full,

the second one then charges up.

The other thing you can do is connect your charger to the engine and then control

the charging via your battery selector

 

Edited September 18, 2017 by antonywardle

[SquidMarks]

Hi Anthony,

Im trying to stay away from a VSR and also energising the whole boat by using the selector. The battery switch needs to be in the "off" position while the charging is occurring.

I think i may have found a way combining Zorans idea with my easy to connect 240V 15A power plug. (im using 15A plugs so kids or anyone silly enough to try and connect the charger into regular home mains will not be able to).

I think i have it so that the batteries are both connected only when the plugs are joined and charging can occur for both batteries at the same time. When the charger is disconnected then the batteries are isolated as usual.

Have i overlooked anything?

Here is a quick wiring diagram.

 

 

 

Edited September 18, 2017 by SquidMarks

[zmk1962]

Hi Squidmarks,

The circuit you have drawn is the basic wiring circuit I have installed. Once I had that, I decided to install additional controls as per my modified circuit diagram below:

LEGEND:

meter = cheap voltage meter. Cut off the electrode probes and fit male bayonet plugs, female plug fitted to switch box.

SWITCH BOX

Sm= master switch (isolates the charger from the circuit)

S1= switch to control charging to battery 1

S2= switch to control charging to battery 2

 

With the circuit connected via the multi pin plugs in the boat I can now charge both batteries, charge one or the other, isolate out the charger and test voltage on both batteries or individually. All from the charging station and without having to undo boat covers and get back in the boat.

I am not sure how far the boat batteries will be away from the charger. But I understand you want to use the 240V 15A lead.  Just consider that you are dealing with DC electricity here. DC does not travel well on thin wires and you will get voltage drop over distance which may impede with your charging efficiency. You will get less drop with thicker wires. (I'll let more electronically minded people comment further on that.) In my circuit I used 3-4 mm2 garden lighting cable. The stuff they use to wire up LED garden lights which are all long run DC circuits. Its cheap and available from Bunnings. This also drove me to the Andersen type plug as the connector.

Cheers

Zoran

 

 

Edited September 18, 2017 by zmk1962
inserted correct diagram

[zmk1962]

PS - If you look at the picture of my switch box you will see 5 toggle switches.  Top down, the first is the Master (isolates the charger), the next four are for batteries. First is the breakaway battery on the trailer, then the next three are the boat batteries.