Battery question?

[Gundog]

I have 2 batteries in my boat and an onboard charging system the charger is a Guest 12 amp 2 battery charger. I bought my boat 2 years ago and at that time I did not have the extra $$ to spend on high dollar batteries.

The battery that came with the boat is a smaller size I am not sure the group size, that battery has always started the boat just fine. The second battery I added and installed a Perko 2 battery switch.

The second battery is a Wal-Mart cheapo marine / RV deep discharge. I have all of my electronics wired to that battery and I installed another battery switch that is just an on/off switch.The battery it came with I use for engine starting. With the 2 switches I can just turn them both off when I get home and I don't have to worry about leaving anything on also if a fire were started on board I could switch them both off.

I bought the Wal-Mart battery with the idea of upgrading it later the problem I have is the Wal-Mart battery is sometimes it does not last all day if I am on anchor and leave the FF and radio on. I also have a problem with my trim tabs drawing enough that my FF turns off due to low voltage. I am planning on putting the trim tabs back on the strting battery. I have a TR-1 and it also is fed from the electronics battery and it also quits working before the days is through.

I am going to upgrade batteries now, should I change both batteries to the same type dual purpose or buy a new deep discharge battery? I am also wondering what brand would be best for the money

Here are some of the things that I have on the boat that need to be fed 2 electric down riggers, FF, Radar, TR-1, Bait pump, VHF radio, CD player radio & crab pot puller.

My main motor is a Yamaha 150 and kicker is a Yamaha T8 with tilt & electric start. I would like for the kicker to charge both batteries when it is running and the main to charge both batteries when it is running? What do I need to do and is this possible? Chuck if you are out there or any other marine electric experts help?
Thanks Mike
:help:

[Snowwolfe]

If you want either motor to charge both batteries while either are running then the battery selector switch just needs to be turned so both batteries are on.
But unless you run either motor throughout the day running all the electronics, down riggers and your pot puller I doubt any battery would last.

[Boats]

I run 2 Optima marine batteries on my NR Seahawk with 150 Yahama.
They last forever.

My electronics include: (2) 25 watt Marine VHF radios, Furuno radar, Depth Sounder, Chart Plotter, twin bilge pumps, High output strobe lights (for Coast Guard Aux) etc... etc..

Optima batteries cost a bit more but are more than worth the extra money. They last much, much longer than conventional batteries.

[chucks electric]

hello, yes replace the batteries with the same type, size and date. the problem you are having could very well be caused by an inadequate battery charger 2 amp trickle chargers wont recharge in a reasonable amount of time.
trust me on this one 1. you need more than one house battery the amp hours used throughout the day just over whelms your one battery. 2. you should have an automatic charge relay to recharge your house circuits while under way. 3. you should use a minimum of 2 group 31's in parallel 4. don't use 2 6 volts in series because you only increase voltage not capacity. in a limited space area the best way to get battery amp hours and reserve capacity is to stay with 12 volt batteries. 5. if using an inboard i would set up the alt to charge the house batteries then charge the engine battery through an ACR. the house batteries are your highest usage battery bank therefore it will need more attention. the engine battery is hardly used in comparison. because you use an inboard its a lot harder to wire the alt to work this way and may have an effect on your warranty. you will need to buy a battery charger that is at least a two bank charger for simplicity sake consider your house bank one big battery if your using more than one.
by having more than one house battery in parallel the bank wont discharge as deeply and will recover quicker, while underway and then on a charger.
remember an alternator will not recharge a deep cycle battery period! use a dedicated marine on-board charger that is at least 12 amps.
use 3 group 31's they will fit into group 27 boxes. if you can afford AGM battery use them. i do not recommend optima batteries they fail at random, if you don't believe me go by northwest battery and look at the pallets of warranty returns. if you would like a list of materials to use just ask. hope this helps

[Snowwolfe]

"remember an alternator will not recharge a deep cycle battery period!"

I have to ask about this. I have two batteries on my Sea Sport (one being a deep cycle) and during the boating season I never hook up a charger on my batteries. If the alternator is not recharging my deep cycle battery then what is?

[Don't fish e nuff]

I,too, am interested in the answer to the question Snowwolfe asked. I have an Optima running my I/O. I have a deep cycle for my trolling motor. The two batteries are in parallel but going thru a constant duty solenoid that is wired to the "on" key position. Engine off, batteries are separated and I can always start the big motor. Engine running, key switch in the "on" position, batteries are in parallel and charging. I have been using this set up for four years and have not changed out the batteries. On a side note, yes, I know that when the engine is cranking I am drawing off of both batteries so they are wired together with four Gauge cable. I apologize if this is what is called "high jacking" a thread, but I felt the answer can benefit all.

[chucks electric]

hello, that was a loaded statement and it got ya thinkin. there is a difference in recharging a battery and just putting a surface charge on one. cranking batteries will recharge, deep cycle will not. the reason being is the alt on both inboards and late model outboards are automotive type, cranking batteries will want to recharge similar to the way they discharge- fast. deep cycle batteries don't like to recharge quickly they discharge slowly and like to recharge slowly, but need to be maintained at about 14.4 to 14.6 volts for several hours.
while the deep cycle needs to stay at this voltage for several hours the alternator sees the surface voltage come up it has no idea that its recharging a deep cycle as this happens the voltage starts to drop, voltage at this point is critical a few tenths of a volt make all the difference in the world. this is where Balmar alternators really shine as the regulator is programmable and can be adjusted to properly follow a 3 stage recharging format. there is only one volt difference between bulk charge and float stage.
most of the time there is only a surface charge on a deep cycle battery that doesn't have a dedicated charger if tested you can see what I'm talking about but you need a conductance tester to do this. simply putting a load on a deep cycle battery isn't the right way to test, remember its a storage battery not a cranking battery so load testing is NOT the info your looking for. as Gundog found out as his deep cycle just bit the dust. by not recharging a battery properly and completely after ever use will shorten its life.
the other topic is mixing batteries, this is a no no as different batteries will recharger and discharge at different rates one battery can use the other as a crutch and compromise all of them.
remember 4 ga cable is never acceptable for cranking an engine, its just too small. 2 ga is ok as long as your runs are short.
there is so much to batteries that its an education in its self.

[Don't fish e nuff]

Thanks much for your reply. I understand all that you have said, agree with most of it, and have learned a little in the process.

[cptdarel]

Chuck's Electric, thanks for the expaination of the theory recharging, BUT, I must admit I'm left a little confused. How do campers and motor homes get away with alternator recharge systems on deep cycle batterys, I have a 4-D deep cycle in my Camper, I have used them for 8 years, so in theory am I just using a surface charge? and or must a deep cycle be drawn down to 0 volts then charged back up? got me realy thinking, Hmmm.

Never mind, I think I've answerd my own question.

www.batteryfaq.org/carfaq16.htm (http://www.batteryfaq.org/carfaq16.htm)

[Snowwolfe]

Sorry, I just dont buy what I read in that battery article. I live in Alaska and in Sept I disconnect the negative terminal from my two deep cycle batteries in my rv. These batties sit in my rv from sept till may at temperatures as low as minus 25 C. In 15 years with 3 rv's I have never had to replace a battery yet.