Installing a 3 bank charger...looking for suggestions

[SoCalAngler]

Well....I recently purchased a Minn-Kota M 315D 3 bank charger. Looking for some ideas on install....

Location: I need to figure out a place to mount that is out of the way. Was thinking under the porta-potty holder/step (back of changing room), in one of my battery storage compartments at bow, or ????

Wire type and size. I am going to have to add lengths to the charger cable that lead to batts, as the charger may ne be close the batts, especially since two are for trolling motor and one is starting batt and they are located on opposite sides of boat. I believe 10ga should do the trick considering the longest potential distance would be around 20 feet from charger to batts.

Should wire be marine tinned wire or is good 'ol copper home wire good enough? Obviously I would use sheathed wire in either case.

Other charger install ideas/suggestions?

Thanks

[Todd4]

Well, since you asked ............................

I installed the MK 4 bank charger last summer. I have a start, house, and two trolling motor batteries. That charger is heavy! I mounted mine to the floor under the console - it's off to one side so it doesn't take away from my storage.

Some things to think aboout:

After installed and first checked out, you still need to be able to see the charging lights on the unit every once in a while to make sure all batteries are still charging correctly. As long as you can see it (with mirrors or minimal dismantling) for checking/troubleshooting purposes, you can hide it away wherever it's most convenient.

I wouldn't mount it INSIDE and enclosed battery compartment, unless the battery is a gell cell type. Regular lead acid batteries expell acid vapour that will eat up the charger over time.

MK wants 6" airspace for cooling around the charger. I don't have that much on one side (up against a wall) and it seems to stay nice and cool (just warm to the touch).

MK makes 15' fused extension cables. I don't see the need for them, other than they're a nice neat looking wire package; besides, they're pricey. I think MK recommends 12 ga. extension wire no longer than 15 feet. I used spools of 10 ga. marine wire because some of my runs were longer than that. I would use nothing but MARINE wire in a boat - but that's just me.

MK provides ~5 foot wire leads off of the charger with a fuse near the end. Of course, you need to run the wires so you can gain access to the fuses later. You shouldn't just cut the fuses off because you really need protection on the charger end. But more importantly, you cannot shorten the charger's wire leads - there is a thermocouple imbedded in the wire harness near the end, enclosed in the harness, between the charger and the fuse. So you cannot just cut the wire anywhere you want to add your wire extensions - the charger won't work without the thermocouples. I just cut the ring connectors off and soldered my wire extensions there. I had to loop MK's wire leads so I could maintain access to the fuses inside my console. If I had cut them shorter (to fit better), I'd have cut off the thermocouples.

Finally, fuse the battery end of your wire leads also (at least the positive wires). This means your wire runs are fused at the charger end AND at the battery end. In the event of a short in your wire extensions, you don't want the charger to provide power to a short, and you also don't want the battery to provide power to a short.

Hope this all makes sense. You'll love the convenience once installed. I KNOW I DO - one plug and done!

Todd

[Texoma Toon]

On a two tube pontoon weight at the front of the boat starts to become a problem when you have all the batteries, trolling motor, and now a three bank charger mounted there. I would mount it as far to the rear as possible..

[SoCalAngler]

Thanks for the tips Todd. Good ideas on extension cables and I was unaware on the the thermos inside the harness.

Thanks Texoma Toon on the weight issues on the bow. I am looking to mount the charger in the pop up changing room, under the bench for the porta potty (port side). Does this sound like a good place? This will make my charger leads around 20 feet as the trolling motor batts are mounted at starboard bow.

Questions....

1. Should I mount the TM batts closer to stern? If I do, my charger leads would be shorter, but TM leads to battery would be 20 feet long or so.

2. Where would be the best place to mount (2) 27 group TM batts and (1) 27 group house batt? The only enclosed area is the changing room on the port side.

3. Also, is it OK to run my charger leads and other 12V wiring under deck and secure with stainless cushion clamps?

Thanks!

[Texoma Toon]

On my two tube pontoon I have all three batteries mounted in battery boxes, and a two bank charger on the rear deck behind the fence by the motor. Leads to the trolling motor are run to a plug at the front gate. I have underskinning on mine so they ran them between the underskin and the bottom of the deck and sealed the holes in the deck. My trolling motor is removeable, but I can tell there is extra weight on the front when I have it mounted.

[SoCalAngler]

So......

Now's the time to decide where to mount my 3 batts and 3 bank charger. I don't have an area in the stern outside the fence. Should I try and balance weight by moving batts to center or stern area? Current bow weight includes live well on port side, 2 group 27 batts to starboard, and TM

Current location of batts....

(2) group 27 Trolling batts are located at bow of boat...one in a starboard storage compartment and one adjacent to the compartment in a batt box (close to TM).

(1) group 24 starting battery is mounted in the enclosed area behind the rear live well (close to engine).

It appears to ride fine as is, but I have only taken it out once so don't know how it would run if the two TM batts were brought to rear.

Options.....

1. leave as-is and mount charger in changing room.
2. Bring TM batts towards rear and mount in changing room along with charger
3. Don't know where else to mount????

Thoughts, suggestions???

[Texoma Toon]

If it rides fine with the batts as described then great. I am just not a fan of adding weight to the front of a pontoon.
One thing you might want to consider if you have a BPS close by is to ask the service guys how they would mount them.

[Todd4]

I have a 22' tri-toon with 150, this is what I did (not saying it's correct, just what I did).

I moved the start battery (from near the engine) and added the house battery in my changing room, against the port wall, behind the porta-potty. I added a shelf above the batteries (NICE storage space). I did NOT have room to put 2 batteries near the engine, so that made the decision for me. I added two TM batteries, one in each bow corner, in enclosures provided by the manufacturer. All batteries are group 31 size gell cell. My TM and electric anchor winch are front and center, under the front gate (gate already had cutout bottom for TM). I used 8 gage wire for the winch to run to the house battery. I used 10 gage wire for the charger to bat runs. The manufacturer pre-wired for the TM up front (don't know gage). Oh, I also have a 12 volt charger that directs the outboard motor alternator to charge the batteries while underway (start batt first, then the other 3 thereafter). That's a LOT of wires. I ran everything underdeck, attached to the underside of the floor, in corrogated plastic wire looms. I drilled holes through the floor, and added the factory rubber boots, where I needed to pop the wire looms through the floor. I don't necessarily like those looms, but thats what the manufacturer used, so it all looks the same. I have underskinning which made the job a TOTAL PAIN in the azz - really. All wires are "hidden".

I think my toon is stern heavy with the engine, gas tank and one of my live wells back there, so I wanted to move the weight forward.

Some of my charger leads are at least 20 feet long. I used 10 ga. I'd use heavier gauge wire if you want to run your TM leads 20 feet long. The TM will pull MUCH more power than the charger will ever push.

My start and house batteries are in enclosed battery boxes (MK) to meet Coast Gard or ABYC regulations, since I will likely be boarded at some time(s).

That's all I can think of. Good luck. Let us know what you decide to do.

Todd

OH, I agree with Texoma - temporarily put your weight where you plan to mount it permantently and go for a ride. Decide what is acceptable before you permanently mount anything.

[SoCalAngler]

MK provides ~5 foot wire leads off of the charger with a fuse near the end. Of course, you need to run the wires so you can gain access to the fuses later. You shouldn't just cut the fuses off because you really need protection on the charger end. But more importantly, you cannot shorten the charger's wire leads - there is a thermocouple imbedded in the wire harness near the end, enclosed in the harness, between the charger and the fuse. So you cannot just cut the wire anywhere you want to add your wire extensions - the charger won't work without the thermocouples. I just cut the ring connectors off and soldered my wire extensions there. I had to loop MK's wire leads so I could maintain access to the fuses inside my console. If I had cut them shorter (to fit better), I'd have cut off the thermocouples.

Finally, fuse the battery end of your wire leads also (at least the positive wires). This means your wire runs are fused at the charger end AND at the battery end. In the event of a short in your wire extensions, you don't want the charger to provide power to a short, and you also don't want the battery to provide power to a short.

Hope this all makes sense. You'll love the convenience once installed. I KNOW I DO - one plug and done!

Todd

Hello Todd--

I had a few questions regarding the fusing at both ends of the charger lead extensions. The MK manual states cutting the leads between the fork in the in the output cable and the fuse holders. It further states the the fuses should be within 7" of battery terminals. I called MK to verify the cut area was OK as written in manual and they stated, yes.

Now, if I do as you suggested, and cut off ring connectors, extend cable, and add another set of fuses at battery end, is this really adding additional protection from a short, or do the fuses at the charger end do the same (without the added ones at battery ends)?

Thanks!

[Todd4]

OK I understand your questions and I KNOW I am correct with my answers (but still keep in mind this is the internet ). I researched the out of this also, so I can explain the rationale behind my recommendations. Now, if I can just put it into words that are comprehensable......

Cutting the output wires: Yes, you sound correct about where a cut is acceptable. EACH output wire, starting at the charger end, looks like a single thick black wire (obviously something's inside). Near the fuse end, the thick black wire ends in a black plastic "Y" with two 12 ga. wires sticking out (one red with a fuse and one black, both terminating with ring terminals). You can cut the wires PAST the "Y" (that means anywhere in the ~6" long, 12 ga. wire area). The thermocouple is inside the 'single thick black wire', near the "Y". But I would NOT cut the fuses off this end (see below)! So that leaves essentially just cutting of the ring terminals and ~3" of wire (if you want to keep the wires even in length).

Fusing at both ends: First, you already have a fuse near the charger's end. Second, ABYC requires a fuse at the battery end (within 7" or 12" - I don't recall) for any non-starter motor cable at the battery end. So, if you did NOT need to extend your output wires - you're golden! (Let's assume it would be very difficult to wear through the 'single thick black wire'(s).) But this is the real world and you need longer wires. You could cut the fuses off the charger end and move them to the battery end (and extend your wires in between). However, while boating, if you have a short to ground in the middle of your wire extensions - the fuse pops - and your battery is protected. However, if you are charging and get a short in the exact same place, you just shorted your charger directly to ground with no way to protect it (you removed the factory fuse protection). Of course, if you fuse only the charger's end and short to ground (in the same place) you fry your battery, This is what I mean by, "you are feeding your extension wires from BOTH ends, so you need two fuses", depending on what you are doing - using or charging. This is not the same as powering a light or radio from a battery.

If you do choose to fuse both ends : I recommend resettable breakers at the battery ends. Google: Rig Rite Marine Circuit Breaker Part # 1020. I don't remember where I bought them, but that'll get you started on the style I like.

Cutting the charger's AC plug off: Yeah, you didn't ask, but I almost did that to put an outlet on the outside of my boat. Don't do it - for some strange reason it voids MK's warranty - just thought you 'd like to know that one. Oh, and if you can find, and buy, the MK through-panel AC plug adapter and think its the perfect solution - guess again - the charger's AC plug does not fit. Go figure:

So, hope you understand, or I totally confused you even more. Ask more questions and Ill try to answer - the best I
can.

Todd

[SoCalAngler]

Thanks Todd--
Very clear explanation. Now I know the reason for fusing both ends. Since the positive and negative are both fused, I'll do the same at battery end.

A nice plug on a panel would be nice....

but if the MK plug doesn't work, I may just have to leave it hanging and use an extension cord

Thanks for all the assistance!

[Todd4]

Glad you understood my comments/suggestions. Sometimes it's hard to convey a concept on the net, so I add more description than otherwise may be neccessary. I fused both positive an negative also. I think that may be overkill, but hey, you're floating in water on bare aluminum tubes. Do whatever you're comfortable with.

As for a through-panel adapter to plug a "shore power" extension cord into: I really really really want that option, also - so far I've had to crawl under my cover and under my console every time I want to plug in the "shore power" extension cord. So this is what I've come up with so far (any and all suggestions welcomed). You can get MK's through-panel AC adapter and glue/epoxy/5200 the charger's plug into the adapter. BUT that essentially still 'voids' your charger's warranty because you'll never get the charger out from behind the panel to a service shop (the adapter with attached power cord can only come out of the front of the panel, leaving the charger 'stuck' behind the panel).

So, here's the only thing I've come up with so far - glue a 1 foot long extension cord into the back of the MK through-panel AC adapter and then plug the charger's power cord into the other end of the extension cord. If you get an extension cord with a single male end and a triple female end, then you can use the two extra female plugs as "shore power" for other things too. I've seen 1M x 3F adapter extension cords this short before, so I know they make them. IF you ever need to service your charger, simply unplug it from the short adapter extension cord that remains glued into the back of the MK adapter plate.

Of course, if your charger cord is a long ways away from where you want to plug in your "shore power" extension cord then you can use an appropriately longer adapter extension cord. (I just described my set-up).

OK - that's all I got. Lemme know what you decide to do (PICS ). Thanks.

Todd

[SoCalAngler]

Todd--

On the resettable breakers.....

I have a resettable breaker for the TM (between TM outlet and batteries).

Is the resettable breaker you speak of (Rig Rite) between charger leads and battery? One end of the Rig Rite resettable breaker attaches at battery post and charger leads would attach to the other end of breaker, correct?

Also, where is a good place to get the 10/2 marine duplex wire for extending charger leads? I need a 100' roll, as two batts are at bow and one is at stern. Charger will be near middle of boat in changing room; hence the need for a 100' roll. Also need, ring terminals, butt connectors, some sort of through-deck cable protector to protect duplex wire as I fish it under deck from charger to batts.

Thanks

PS...have you seen this type of resettable breaker? They look pretty nifty and could be easily replaced in an ATC fuse holder as needed.

[Todd4]

If the resettable TM breaker came with the trolling motor, I'd use it there - it's there to protect your TROLLING MOTOR (I think mine is on the TM). Remember your resettable breakers/fuses are used to protect your WIRES (and subsequently the battery and charger), not your end devices. For example, if you have a 30 AMP rated and protected wire going to a 7 AMP radio, the radio will FRY long before the wire does or the breaker pops (you need to ALSO protect your radio with a 7 amp fuse near the radio).

Correct. To protect your battery, the Rig Rite resettable breaker attaches to the battery post and the charger wire attaches to the other end of the breaker, as you describe. Remember they are directional (a BAT end and an AUX end) - and be sure to use the proper AMP rating for your WIRE. Of course, you first size your wire to feed all your end devices.

I got all my wire, battery cables, end terminals, solder slugs, wire loom, etc from www.gregsmarinewiresupply.com, simply because someone on these boat forums recommended it. However, someone else recommended www.genuinedealz.com (don't judge a website by its name ). I know Greg's gives great service (not knocking the other one, just no experience). I also know Greg's sells duplex wire (although, I bought single wires for my AC and DC chargers and loomed them together). Check both of them out. Whatever you do, do NOT buy from West Marine = $$$$ (but when you have to have it on a Saturday afternoon, well then.....).

Measure your wire runs out first - the length needed may surprise you, 'cause you can't run point to point in a straight line. You have right angle runs and must run up through the deck an loop up over to your battery. Nothing worse than not being able to finish your project and button everything back up 'cause you ran short of supplies (wire, etc) and have to reorder and wait. As for through-deck protection - hmmmmm, most just fill smaller holes with silicone sealant so it cannot move. They do make various through-bulkhead wire protectors, but for thinner wall pass-throughs. You can check http://www.aircraftspruce.com, but bring plenty of money.

RE: ATC resettable fuses. LOL, I love those things. I have a whole set of them. BUT, I only use them for troubleshooting shorts, so I don't pop a dozen fuses in the process, thinknig I 'fixed' it. They should work fine (that's what they're made for) - I just have no experience with them for long term use.

Speaking of troubleshooting - buy a few extra resettable breakers/fuses and carry them with you on the water so you can quickly determine if you really have a short or a bad breaker/fuse.

When routing your wires - if you are against, or going around, or through, a sharp edge they WILL chafe through, eventually. Don't take short cuts. Not that I would know from experience, or anything. But I do know its amazing how far you can take a new motorcycle apart on the side of the road with just the little OEM tool pouch provided.

Good luck, and have fun with your project.

Todd

[SoCalAngler]

Todd...Thanks for all the tips

Ordered a 100' length of 10/2 marine tinned duplex, butt connectors, ring terminals, dual wall heat shrink, and 30amp ATC fuses with holders (like the ones that came with the MK charger). I checked and had a 24V 50amp resettable breaker for TM. It was about 6"-7" from battery.

I think I'm good to go.

Thanks again!