Marine Battery Question

[AGP]

Hi Guys,

Would appreciate a few comments on my below situation. I purchased a new Quintrex Renegade from a dealer as a complete boat, tralier, motor package which included electronic fit out around 2 years ago. It came fitted with a deep cycle battery at the front of the boat, purely for running my Minn Kota I-pilot and no other electrics attached to this deep cycle.

The rear of the boat was fitted with a Century marine cranking battery. This battery was setup by the dealer to also supply power to my sounder, Nav lights, Anchor light plus bilge pump for live bait tank.

The Yamaha 50hp 4 stroke has an alternator attached which I was told by the dealer would charge up the battery enough to keep all those electrics running, Plus never have to be trickle charged..

Well things ran fine for a year before one night at anchor whilst running my sounder, anchor light and live bait tank the battery went flat.

What could've turned into a dangerous situation didn't as another boat passing by was able to tow me back to the ramp although it did take the poor bloke over an hour!

Unhappy with the dealer fitting that amount of power sucking electrics to a cranking battery I bypassed them and went to see a specialist battery store. The owner there talked me into buying another cranking battery and not a dual purpose. His reasoning was that this new cranking battery was of much larger capacity and would power all those additional electrics considering its larger size and charge from the alternator when my engine is running.

After the breakdown I am still nervous though, I am regularly up against cliffs fishing and fishing at night in areas you would not want a flat battery in.

Am I kidding myself not running a dual purpose? The cranking battery is a Lion and I cannot connect the other electrics to the deep cycle that supplies the Minn kota due to how the dealer has done the initial setup.

Any comments/experience would be great.

Cheers

[Welster]

If I had the room I'd probably run a second starting battery with the off, 1, 2 and 1&2 switch and leave the set up as is. If not I'd look to utilise my deep cycle battery more. There are others on here far more knowledgable about this stuff than me. Going by your description it's a first line safety system that must work so I would err on the side of caution.

I was out from 4pm to 2 am the other arvo night with live bait tank, sounder and Nav lights running with no dramas on my first battery, no signs of going flat. ( boat is Stacer 5.7 with 150 etec). We did do a few short moves whilst drifting and a run in from the heads to Yowie bay to change spot. It's good piece of mind having another fully charged battery ready to switch over.

However the first thing I would do is have it on trickle charge and make sure I'm leaving home with a fully charged battery.

[boattart]

I'm no expert on batteries so will leave the set up to someone else but I do believe all boats should carry a jumpstarter as a safety measure and in your cases sounds like a great fall back. The only other thought is that while your alternator will charge the battery if you are fishing close to shore it's not getting a lot of time to do it. I know when I fish close in doing short runs between spots and drifts I dont put nearly as much charge in as say a 10 hour day at trolling speed which I often do and keeps my batteries topped up.

[Katoe]

I agree with Boattart I carry my jumpstarter whenever I go on long outings especially night fishing touch wood I haven't needed it yet but it gives me piece of mind that if I get a flat battery I could turn all electrics off and jump the motor. My jumpstarter cost $120 and has a USB port a 240v inverter and an air compressor quite a handy little unit.

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[AGP]

Thanks for the input guys. Katoe where did you get the jump starter for $120 from?

This seems like a great option for piece of mind especially for the night sessions. Feel free to PM me the details.

Thanks!

[Katoe]

Trying to PM you mate keep getting an error message.

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[Nolongeramember]

I have a similar set up to you mate battery wise. Starting battery is 90AH and engine is 60HP. I always charge my batteries at home after every trip to make sure they are full for the next trip. I've never had any problems in a long, long time and I run lights, bait tank and sounder for the whole trip and go hours at anchor running all these things.

Judging by voltage and how long it takes to charge after a trip, my starting battery never goes below 3/4 full. If it did take a long time to charge then I would know there is something wrong with my engine charging system or battery etc and check it out.

You should check your engine is charging properly.

What size cranking battery do you now have?

[AGP]

Got the PM Katoe cheers mate!

Roylo i'd have to double check what size although I know its of much larger capacity then the original one the dealer installed.

I was more concerned that its a cranking battery running a host of electrics that a deep cycle would be better suited to run so wouldn't a dual purpose be better suited?

Alternator is working fine checked out recently with my 200 hour service. I think when the original went flat it was a case of short trips with the engine/alternator on then long sessions using multiple electrics at anchor so I was taking out more than was going back in. I never worried to much about it going dead because the dealer said I never need to trickle charge due to alternator.

[The Incredible Hull]

Alternator is useless, unless you're using the boat everyday/once a week. That's why we don't need to trickle charge our cars.

If you don't trickle charge, it will slowly die over time. Once you lose a cell its a goner. I've tried reconditioning my old battery with a lost cell, no chance.

[Nolongeramember]

Being a cranking battery is fine and would be what I would want. You are starting the engine with it. I doubt there is little if any difference in batteries labelled as dual purpose to just a cranker anyway. Proper deep cycle batteries are different but are not suited to starting as much as a cranking battery.

Your battery should never go below half with normal use. You need to be aware that you cannot stay with all electronics running for extended times like 5 hours straight without running the engine in between.

Also, don't always listen to everything dealers say. Most boats don't get used often like cars. You can't go wrong charging and storing your batteries full after every trip with a good step charger.

[brad_tate]

I am also not an expert and was initially thinking of running my house circuit off my deep cycle so I didn't flatten my crank battery. My dealer told me that was a bad idea for two reasons, firstly the deep cycle is not designed to be drained gradually over time, and secondly that I would need a rewire to provide the deep cycle with a bus to connect the rest of the electronics.

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[hucho hucho]

Cranking battery is naturally discharging 1% of capacity per day. I always recharge my 2 batteries after every trip and then again before next trip. Two fully automatic charges will do the trick. Alternator, in my opinion and experience, is not enough for the boat usage.

[zmk1962]

I agree with the previous comments:

i) get a second starting battery if you are concerned about safety and need a quick start due to dangerous conditions - consider the time difference in flicking a switch vs undoing battery boxes and hooking up a jump starter (or as I have suggested below - relocate your 2nd battery).

ii) keep your batteries charged and topped up using a trickle charger when at home. You can't rely in your alternator unless you are doing long runs. I have one battery that is 10yrs old and just starting to go now.

If your interested I placed two posts on my set up and the considerations taken into account to design the set up in another topic http://www.fishraider.com.au/Invision/index.php?showtopic=79491. It may be a bit of overkill for you but the set up has worked for me since I rewired the boat in 1997.

Here is also a picture of my trickle charge set up at home: 4 batteries (1 trailer brakes, 3 batteries on boat). Any battery can be tested and trickle charged individually or in any combination without undoing the boat covers or getting in the boat. I have a 4pin plug in the boat to which I attach the corresponding 4pin battery charge cable, and a 2pin plug on the trailer battery box.

One other comment - lead acid batteries typically die as a result of 1) being left discharged, or 2) due to vibration - mechanical shock. Its all to do with the lead plates eventually short circuiting (each lead plate contributes 2V). I understand you have a battery mounted at the front of the boat - this is typically where you will experience the MOST vibration and shock pounding through waves. The stern of the boat offers the smoothest ride. Consider relocating the 2nd battery to the stern and introducing a battery switch (giving you choice of 1,2, both, off). This will give you an alternate start battery if you need it and simplify the charging set up for both batteries. Admittedly you will need to run heavy cables to the front to run your electric motor but it seems to me this would be the simplest solution for you.

Edited January 6, 2016 by zmk1962

[AGP]

Thanks to all for your comments, Much appreciated.

[The Incredible Hull]

Go grab a multimeter, its the best to way to see if your battery is charged, and if it is holding charge.

Each cell should have around 2.2 volts with 6 cells, you're looking at anywhere between 12.5 - 13.5 volts.

When a battery is fully charged, it should hold the maximum for at least a few days, so a good test is to measure the voltage the following day, you'll know if you got a dud battery if its not holding the same or a very similar charge from the previous day.

If you ever come across a reading of 10 volts, may as well dispose of the battery, as you've lost a cell.

Happy fishing!

[spaners]

A deep cycle battery needs to be charged and discharged to work correctly,not left to a Alternator to constantly charge.I would charge both and rig up a spare jump cable using Anderson plugs so if you can jump start from the Deep cycle .

Edited January 7, 2016 by wher'd all the fish go

[Frantic]

Plenty of high amp deep cycles with larger crank cap these days

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[shakey55]

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[DrownNprawns]

Over Christmas I went to start my boat and found the batteries were flat so after charging them it still wouldn't start so I checked voltage 12.5 them checked the cranking amps 127 should be 580 ish so 3 new batteries later each with 777 cranking amps

So point to my story is new toy in the tool box battery tester.it also checks starting system and charging systems

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[zmk1962]

Ha! Glad to hear of another 3 battery fiend out there.... glad I'm not so anal after all !

[DrownNprawns]

That is just one bank of batteries. I have two banks which means 6 batteries all up

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[zmk1962]

HA! ... you win.

[DrownNprawns]

Not win when i need to replace them:(

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[night_rider]

That is just one bank of batteries. I have two banks which means 6 batteries all up

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Wow David, you must have a big vessel! That's like a persons weight in batteries if not heavier!

I recently purchased a c-tek trickle that also has a restore setting. It charges my dual setup really well.

In terms of setup, I would certainly recommend the dual battery with isolator switch, this means if you do get into trouble you can isolate your starter to ensure your accessory battery doesn't draw power from your starter if it's gone flat.

[Dhutchy]

Thanks Guys, particularly Incredible Hull. Looks like I will do the multimeter thing, but I suspect given the long period where the boat has been the garage (since moving to Canberra) its probably going to be two new batteries... and a ctek charger.