Converting Onboard Charger

[DrNip]

My Minn Kota Presicion onboard charger is in route and I had an idea which I have searched but can't find anybody else you have done it before. My boat is a 1248 so space is limited. I was thinking of installing the charger to my garage wall. I would cut the factory connects from the charger and leave them hooked to my batteries at all time. I would then buy 4 of these connectors and put on the cut ends along with the rubber end caps.

https://www.genuinedealz.com/anderson-sb50-10-12-awg-gray

https://www.genuinedealz.com/anderson-sb50-dust-cover-black

This would:

1. Eliminate me having to extend the bank hooking up to my trolling motor due to it being to short
2. Eliminate running the onboard charger wire
3. Eliminate me having to mount the unit in my boat therefor freeing up what limited space I do have

I would simply plug in the 2 connectors to each battery and then plug in charger when I want to charge.

Or should I just extend the trolling motor bank wire and mount the unit in my boat? Thoughts?

 

[TNtroller]

I have and use these for making the electrical connections for connecting my TM to TM battery, and plan on putting one more connector on the charger I use, work great, easy to hook up and everything matches.

https://www.walmart.com/ip/Minn-Kota-MKR-12-Quick-Connector-Plug/16419493

 

[DrNip]

Those look to be even better as I would be able to solder the wire and use adhesive heat shrink. Not to mention they are cheaper. Thank you.

 

[1957Crestliner12]

I never caught how many battery banks you have?...I assume 2 since you mentioned 4 connectors.

That's definitely one way to go but those chargers are small, and can be easily mounted out of the way on the boat.

Then you would only have to plug and unplug the charger into 110V.

Looks like you might be trying to do it the hard way...mounting the charger on the garage wall, the expense and installation of extraneous connectors...not to mention having to plug and unplug to two batteries instead of just one connection using the charger.

What does using this charger have to do with extending the battery bank cables from the motor?

Rod
Oriental, NC

 

[DrNip]

Yes it is a 2 bank and I have thought of the things you have stated but was just thinking out loud. The owners manual states to mount it as far away from the batteries as possible. My original plan was to mount it underneath the casting deck but that puts it above and 18" to the side of the trolling motor battery. So then my next option was to mount it on the side of the back bench but then I would have to extend one bank to reach the trolling battery.

 

[1957Crestliner12]

Most all battery charger owner's manuals state to "mount the charger as far away from battery as possible or practical"...etc...

This is primarily for two reasons...1) off-gassing from the batteries while charging which can corrode the charger and 2) the possibility of fire or explosion from the batteries due to spark while charging.

Just be sure the batteries are secured in battery boxes with lids.

I would not be concerned with extending the battery bank cables.

Rod
Oriental, NC

 

[DrNip]

The trolling battery is in a box with lid and the charger would be 18" or so to the side. There is plenty of ventilation. My initial thoughts was this would be fine.

 

[Bugpac]

Anderson connectors. Ebay cheapest price. I would worry about extending them. As length creates voltage drop. Voltage drop creates charger not properly sensing. I would not lengthen them no longer than the extension kits they sell.

 

[DrNip]

Thanks for the link but I'm not interested in extending the cable 13' more than what I would need to with the 15' extension. I only need to extend it 2'. The two batteries are over 6' apart. The charger comes in today and I'll be able to better assess the situation. I am pretty sure I'll have to alter the charger in the end. I'll post back.

 

[DrNip]

Of course now that I think about using the Minn Kota extensions might be a better way. This way I cut the proper length I need off of it with the ends included and splice it to my charger. This would mean only one splice per wire instead of the two splices per wire the way I was going to do it by adding an extension wire per wire.

 

[huntinfool]

I was going to do this very thing. But after searching online, I read several posts saying do not extend the leads due to the voltage drop and the charger not sensing properly. Some even claimed that they had boats catch fire and burn down the garage they were in. This made me think that I didn't want to mess with it. Now there were several that said they had done it and no Ill effects. Some even said to use a larger wire as the lengthening piece.

I think buying the charger with the extending leads from their company with the single splice is the best way to go.

On my 3 bank charger I was going to have to extend all 3 leads 3-4'. I'm going to buy a single and a dual bank charger and just plug the two in.

The plugs TNtroller suggested work great. We use them for several applications. Just make sure you put the positive on the shielded side from the battery so that it will not ground out anywhere.

 

[bulrid8]

Most will never extend their cables more then ten feet. Voltage drop on 10ga wire, at 10 amps, for 10 feet is 0.22v. The charger has no way to know that drop is not in the battery itself. Even if it causes an overcharge of 0.22v, that is not enough for the battery to even be effected by it.

If you are truely worried about it, make the extensions from 6ga. There will almost 0 voltage drop at 10 feet.

 

[muskiemike12]

The Minnkota extension kit has 15 feet of 10ga. wire. I know cause I bought one 3 years ago for my pontoon, as I needed to run bank #2 to the starting battery. It took the whole 20 foot of wire to make it. Wires off the charger are 5 feet in length. It said right in the manual no to run wires longer than 20 feet. Make sure you have a inline fuse within 7" of the battery. My charger sits about 8 inches from my deep cycle battery. I have never had an issue. Just make sure it is vented well.

 

[dhoganjr]

I have both TM batteries mounted in boxes with lids under the front deck. I have a Dual Pro 2 bank charger mounted on the rod box that extends under the deck and the port side battery sits right next to it. I keep it plugged in when the batteries are in the boat, it is not a sealed compartment so they can vent to the air. I have used it like that going on 12 years with zero issues.

Main thing is to make sure they are vented in some way to let gases excape, so when the charger cycles it doesn't explode.

I have been using a regular charger for the starting battery. This year I am going to upgrade to a single bank charger for it, so all I have to do is plug them both in. No more having to connect the charger everytime I get back.

 

[DrNip]

Not worried about extending the banks. Here is what the manual states about extending them:

"If the DC battery leads are not long enough, they may be lengthened by splicing and soldering 12 AWG (minimum) wire. Each splice should be covered with dual wall adhesive lined heat shrink tubing to protect the joint from corroding. The splice should be made between the fork in the output cable and the fuse holder. The fuse holder should always remain within 7” of the battery terminals. The maximum extension length is 15 feet. You may contact the Minn Kota Service Department with any questions. Do not splice the AC power cord, as this voids the three year Limited Warranty."

The stock bank length is only 6'. Why they didn't just make it a couple more feet longer I don't know. My plans are to lengthen the cable around 2-3' at the most. They also sell a 15' extension.

My bet is the people that had problems with extending the cables either extended them too far or did a janky job splicing them therefor causing the unit to fail and/or catch fire.

 

[JMichael]

DrNip » Today, 08:34[/url]"]Not worried about extending the banks. Here is what the manual states about extending them:


My bet is the people that had problems with extending the cables either extended them too far or did a janky job splicing them therefor causing the unit to fail and/or catch fire.

EXACTLY!!! And if you include the possibility of using improper size or type wire, I'd even go so far as to give some odds when making that bet. :lol: I extended mine about 12' with 8 gauge wire (what I had on hand) so mine could reach my starting battery in the back of the boat and have had no problems.

 

[huntinfool]

OK now y'all have me convinced that I am going to go back to my used 3 bank charger and extend my leads.