Marine Battery Question for 55lb Trolling Motor

[MidCoast]

ca @32 degrees 705

Group size 27 dc

cca @ 0 degrees is 575

Reserve Capacity:  175 RC/200 min. @ 23 amps

 

Is this deep cycle marine battery strong enough for a 12 volt 55lbs thrust  Minn Kota trolling motor?   Does 200 minutes mean it will only run for 200 minutes while drawing 23 amps?  

[jmd1]

Here is some info on how to read the battery.  Kind of dry but i hope it helps.  I will add this link too.

http://www.minnkotamotors.com/Support/Battery-Selection---Rigging/

4. CCA, CA, AH and RC. What are these all about? These are the standards that most battery companies use to rate the output and capacity of a battery.

Cold cranking amps (CCA) is a measurement of the number of amps a battery can deliver at 0 ° F for 30 seconds and not drop below 7.2 volts. So a high CCA battery rating is especially important in starting battery applications, and in cold weather.This measurement is not particularly important in Deep cycle batteries, though it is the most commonly 'known' battery measurement.

CA is cranking amps measured at 32 degrees F. This rating is also called marine cranking amps (MCA). Hot cranking amps (HCA) is seldom used any longer but is measured at 80 ° F.

Reserve Capacity (RC) is a very important rating. This is the number of minutes a fully charged battery at 80 ° F will discharge 25 amps until the battery drops below 10.5 volts.

An amp hour (AH) is a rating usually found on deep cycle batteries. The standard rating is an Amp rating taken for 20 Hours. What this means, say for a 100 AH rated battery is this: Draw from the battery for 20 hours and it will provide a total of 100 amp-hours. That translates to about 5 amps an hour. 5 x 20 = 100. However, it's very important to know that the total time of discharge and load applied is not a linear relationship. As your load increases, your realized capacity decreases. This means if you discharged that same 100 AH battery by a 100 amp load, it will not give you one hour of runtime. On the contrary, the perceived capacity of the battery will be that of 64 Amp Hours.

5.Battery Maintenance is an important issue. The battery should be cleaned using a baking soda and water solution; a couple of table spoons to a pint of water. Cable connections need to be cleaned and tightened as battery problems are often caused by dirty and loose connections. A serviceable battery needs to have the fluid level checked. Use only mineral free water, Distilled is best as all impurities have been removed, and there is nothing left that could contaminate your cells. Don't overfill battery cells especially in warmer weather because the natural fluid expansion in hot weather can push excess electrolytes from the battery. To prevent corrosion of cables on top post batteries use a small bead of silicone sealer at the base of the post and place a felt battery washer over it. Coat the washer with high temperature grease or petroleum jelly (Vaseline), then place cable on the post and tighten. Coat the exposed cable end with the grease. Most folks don't know that just the gases from the battery condensing on metal parts cause most corrosion.

6.Battery Testing can be done in more than one way. The most accurate method is measurement of specific gravity and battery voltage. To measure specific gravity buy a temperature compensating hydrometer, to measure voltage use a digital D.C. Voltmeter. A quality load tester may be a good purchase if you need to test sealed batteries.

For any of these methods, you must first fully charge the battery and then remove the surface charge. If the battery has been sitting at least several hours (I prefer at least 12 hours) you may begin testing. To remove surface charge the battery must be discharged for several minutes. Using a headlight (high beam) will do the trick. After turning off the light you are ready to test the battery.
 

State of Charge	Specific Gravity	Voltage
		12V	6V
100%	1.265	12.7	6.3
75%	1.225	12.4	6.2
50%	1.190	12.2	6.1
25%	1.155	12.0	6.0
Discharged	1.120	11.9	6.0

Load testing is yet another way of testing a battery. Load test removes amps from a battery much like starting an engine would. A load tester can be purchased at most auto parts stores. Some battery companies label their battery with the amp load for testing. This number is usually 1/2 of the CCA rating. For instance, a 500CCA battery would load test at 250 amps for 15 seconds. A load test can only be performed if the battery is near or at full charge.

The results of your testing should be as follows:

Hydrometer readings should not vary more than .05 differences between cells.

Digital Voltmeters should read as the voltage is shown in this document. The sealed AGM and Gel-Cell battery voltage (full charged) will be slightly higher in the 12.8 to 12.9 ranges. If you have voltage readings in the 10.5 volts range on a charged battery, that typically indicates a shorted cell.

If you have a maintenance free wet cell, the only ways to test are voltmeter and load test. Any of the maintenance free type batteries that have a built in hydrometer(black/green window) will tell you the condition of 1 cell of 6. You may get a good reading from 1 cell but have a problem with other cells in the battery.

When in doubt about battery testing, call the battery manufacturer. Many batteries sold today have a toll free number to call for help.

7. Selecting a Battery - When buying a new battery I suggest you purchase a battery with the greatest reserve capacity or amp hour rating possible. Of course the physical size, cable hook up, and terminal type must be a consideration. You may want to consider a Gel Cell or an Absorbed Glass Mat (AGM) rather than a Wet Cell if the application is in a harsher environment or the battery is not going to receive regular maintenance and charging. 

Be sure to purchase the correct type of battery for the job it must do. Remember that engine starting batteries and deep cycle batteries are different. Freshness of a new battery is very important. The longer a battery sits and is not re-charged the more damaging sulfation build up there may be on the plates. Most batteries have a date of manufacture code on them. The month is indicated by a letter 'A' being January and a number '4' being 2004. C4 would tell us the battery was manufactured in March 2004. Remember the fresher the better. The letter "i" is not used because it can be confused with #1.

- See more at: https://www.batterystuff.com/kb/articles/battery-articles/battery-basics.html#sthash.thPjDWOH.dpuf

Edited May 31, 2016 by jmd1

[RebelSS]

First, what size boat/engine do you have? Aluminum or glass? How many people will be aboard?  What type of waters do you fish, choppy water, as on a river, lakes, etc. Will you be running against a current? These are all things you need to take into consideration before you decide on a battery. Far better to have a bigger battery than you need than too small......it'll last longer, too. 

[BobT]

18 hours ago, MidCoast said:

ca @32 degrees 705

Group size 27 dc

cca @ 0 degrees is 575

Reserve Capacity:  175 RC/200 min. @ 23 amps

 

Is this deep cycle marine battery strong enough for a 12 volt 55lbs thrust  Minn Kota trolling motor?   Does 200 minutes mean it will only run for 200 minutes while drawing 23 amps?  

Technically, they are all "strong enough." The real question is about capacity. A smaller battery will typically have a lower overall capacity so it will not deliver the necessary current for as long as a larger battery. As Rebel already mentioned, the "necessary current" is dramatically affected by how you use it. The faster you run the motor the higher the demand on the battery. Ergo, higher speed settings, heavier boat, strong winds, water current, all add to demand on the motor and therefore the battery.

A 105 AH battery isn't too bad. I think that's what I use for my 12v 55# Powerdrive and it will run for hours on a battery charge running my Sylvan Adventurer 1600. My brother-in-law had the motor before me and he used it for years on his Lund Mr. Pike 17.5. We can run all day (not continuous of course) on a single battery. 

[Surface Tension]

115 AH were very common but the 105 AH are now. That is fine for any boat.

I can troll easily for a day with one105 but I'm not going over 30% and can stretch that out over two days.  If you need more reserve you get another battery and hook them up in parallel. + to + and - to -  This is 12v with twice the reserve.

 

[BobT]

Hooking up in parallel can be nice but if it's not too much work, using one at a time can be an advantage in another way. With batteries connected in parallel there is a risk. If for some reason one of the batteries develops an internal short, it can damage both batteries or if one battery begins to lose its ability to hold a charge it can draw down the other one along with it. 

Just food for thought.

[Surface Tension]

 My last set of marine batteries were over 10 years old.  

[gunner55]

We have ours wired like ST & with our on board charger,which charges off the outboards alternator,they are fully charged by the time we get back to the dock 85-90% of the time.It's a 55# PD & size 27 battery set up

Edited June 4, 2016 by gunner55

[BobT]

On 6/4/2016 at 7:29 AM, gunner55 said:

We have ours wired like ST & with our on board charger,which charges off the outboards alternator,they are fully charged by the time we get back to the dock 85-90% of the time.It's a 55# PD & size 27 battery set up

Hard to believe your outboard can recharge your trolling motors that fast unless you're driving a loooong way. The starting battery may not take much time but....  

[delcecchi]

Modern motors really put out the amps.  For example the alternator on the new merc 150 fourstroke is 60 amps.  So putting 20 or 30 amp hours into a battery in a decent run on a good sized lake seems reasonable.   That would be 40 amps for half an hour....

[BobT]

That is quite a bit better than I would have expected.

[delcecchi]

Well, older motors had way feeble charging systems.  I think my 98 115 merc might have been 20 amps.  or less.

edit:  I looked it up.   16 magnificant amps.   Comes off a coil in the stator on top of the motor.  No separate alternator. 

Edited June 17, 2016 by delcecchi

[gunner55]

Most of the new 4 strokes have high output alternators(45 amp+) like del said.Ours is a 02 Yammie 115 & it's a 2 mile run out to the south end of the main lake,where we usually fish, probably 3.5-4 to the north end