Kowalski

Thanks for the tip. I keep replacing mine about every other year. I'll give the Optima a try.

PapaDave

Do your batteries Winter in Cold weather or Mild weather (State). Inside garage or in boat outside.??

Salmoneater22 Loc: I live in S.E. Washington state.

Optima is good battery but the price is prohibitive if you're a payday to payday type fisherperson.

Kowalski

By gollies, I store them in my garage over the winter because we can get temps down to zero and below at times here in Central Oregon. Probably not necessary, but it makes me feel a bit better. I guess when I can't boost the batteries back in the boat, I'll just have to bank fish. :)-

FixorFish Loc: SW Oregon

I have only 12v trolling motors, so my useage is somewhat different than yours, but should still be relevant. You say size 27, which is a huge and HEAVY honkin' mass... 60+ lbs, could be 70+, depending on brand AND TYPE...... And no, I don't mean, is it deep cycle (as ALL trolling motor batteries should be) , I mean is it a STANDARD (lead acid, gotta check water levels), a GEL type (which I know nothing about, sorry) or is it AMG (glass-mat, sealed), which is what I have gone to for several reasons.

Firstly... it's sealed..no chance of spillage, leakage, never have to check H2O levels in each cell, worry about the integrity of the cap, etc.
Secondly... while I have no hard evidence, I believe it charges quicker than a standard and lasts longer, imo (have had my first one 3 yrs now... EASILY 80-100 charging cycles.... still strong)
Thirdly..& maybe most important... size and weight.... I have gone to a deepcycle AGM battery made for handicap scooters. Basically 6"x6"x8", & 23lbs !!!! 35 amp hours. I have one in a "playmate" cooler (great fit and sturdy w/ good handle) that I cut a little (1"x3/8") slot in the edge of the lid for the wiring, and use it w/a 30lb Minnkota on my SeaEagle 285fpb,.... have TWO on my Livingston lake boat w/ either a 34lb or a 50lb motor,.....planning on a bank of four (still under 100lbs total and only about 1 1/2 sq. ft area !) on the small pontoon/party barge I am working on.
I simply cannot stress the convenience of the above attributes enough.

For a 24v system you obviously need two 12's.... standard, in a size 27 is adding at least 125-150lbs to the boat....lighten your load !!
These little gems are a Duracell (DURDC12-35) from Batteries Plus... about $90-95 last ones I bought. Love 'em....and now we can bring a bigger cooler with more food and beer (a friend's astute observation !).

Final thoughts -- not sure about "memory" on these battery types, but as far as I know, only Lithium ion WON'T have diminished life by re-charging a minimally discharged battery.... definitely TRY to run down as much as is practical before charging.

Do be sure to use Deep Cycle only. A real smart car guy told me about the "vanes making up the banks inside and their spacing allows..... sorry, he lost me after that ! LOL !
Just DO NOT USE A BATTERY LABELED "MARINE". If it lists "cold-crank power" at all -- you have the wrong one, it's construction will not stand up to the long drain periods (ask YOUR smart car or boat guy...he knows details).....

.....or do the "Yeti cooler Logic" thing and buy a couple of those orange, weird, 6-pack-looking, "top-of-the-line" batteries, I saw at a local shop........2 will ONLY set you back about $780 !!! Get effin real.
Now there's a LoL !!!

BILLBYRD1 Loc: Prattville Al

I just read they have a 36 volt batter that a couple of pros have found out about and they a are raving about it. It was in the paper magazine from Basstmasters. My paper editions and my magazine prescription get hear at the same time. I read the paper addition first while in my porcaline ("southern sounding") office. Then I read my magazine edition. I will make an effort to go back and do some professional reading

ndplume59

West,
There ARE much better solutions than Lead Acid IF you'll take a few minutes to understand Lithium and Lead. I know how you feel about the constant maintenance of Lead Acid, here is what I found (its long) -

Bay Boat Dept:
I personally run a 12V MK RipTide on 1300# 17ft bay boat. My normal trip is 6hrs, most of it running on speed 3 while on course lock (fishing a bank for example) in Salt water. I rarely hit speed 10, but have done a few 15 minute runs at speed 8 to cross a bay without the outboard. I'd rather not run electric items at their rated max. After a typical day, it takes about 20A of juice to charge my battery. My charger measures how much juice I put in the battery.

I'm using a 12V 100AH lithium battery. Specifically a LiFeOn battery. The chemistry is important. LiFeOn batteries last 2000 to 5000 cycles. That could be a 20 year battery at 120 trips/year (2400 charges). That is projected cycles (although I believe its true), I haven't run my batteries for 20yrs. Yet. My battery is from 2012, so I have a few years on it. For a 24V system, I wouldn't expect much difference in the amp use, (because the voltage is 2x).

Lithium Fire Dept:
Can't skip this. Tribal knowledge has it that lithiums catch fire. The media loves to play that up, sells alot of advertisement. The "trick" to not catching fire is A) Use LiFeOn battery chemistry and B) Charge properly on a per cell basis. This means NOT charging them > max voltage per cell. For LiFeOn, that is ~ 3.65V. LiPo and Li-ion are NOT LiFeOn, so don't confuse those chemistries.

Easy Street Dept:
When you buy a lithium battery, it will have a BMS attached to it (inside actually) that will be designed to not allow a cell > 3.65V. No BMS = No Deal (imho). The BMS will stop any charge current once any of the internal cells hits the 3.65V level. It will also stop any discharge current when any cell reaches the min voltage (~2.5v/cell).

Voltage Dept:
After charging to 3.65V, the LiFeOn cell will drop to 3.3V after a short time. Also, a LiFeOn battery pack will have 4 cells inside, so the max voltage will be 3.3 x 4 = 13.2V and the discharge voltage will be 4 x 2.5 = 10V. Since a lead acid is discharged at 11V, then I expect the MK will shut off near 11V, so its unlikely that the BMS will shut off at low voltage. I haven't run mine down that far yet to find out, so I can't be certain on that. (For a 24V setup, double the numbers, of course).

Convenience Dept:
Did I mention my battery weighs 31#, the lead ones were 65#. Lithiums have no acid in them and are all sealed. My flooded lead eventually ended up sprinkling my jeans with acid, putting pin holes in them when I was servicing them. I'm so glad they are gone. Also, I can grab my lithium (un-plug the connector of course) and lift it right out of my boat. Any time I want. The lead, 2x the effort and watch the acid.

Cost Dept:
Are LiFeOn batteries expensive? Depends on how you see it.
My battery was ~$500 in 2012. They are about $400 now it seems and if you watch, you can find some lightly used medical batteries in the $200 - $250 range. If a battery was used for 2 years, charged every day, that is about 700 charges. Suppose it only lasts 2000 charges, then you have 1300 charges left. At 130 trips/year, that is still 10 years? For $250 = $25/year, no acid and no 65# batteries to deal with?

My lead ones were ~$120 and yes, they lasted 3~4 years or so. So ~$30 to 40 per year. I only fish about 30x per year, so at 1500 recharges, that is 50 yrs. There is another thing about lithiums, they don't sag like lead. Even at 50A juice. They generally sag about 1/10th that of lead, so its hardly noticeable. With lead, you know when you're getting low, they just don't put out the juice.

You have to do the math for your situation and see what kind of deal you can find on the batteries. You won't need as high of a AmpHour battery with lithiums as you do with lead.

How to choose a lithium?
I don't sell batteries, but if you're planning to get one, figure out what your max current draw is (put a clamp meter on one of your wires while out and "open" the MK up). What ever that is, make sure your LiFeOn battery BMS allows at least that much current. I suspect you'll be in the 50-60A range, so a 80A or 100A BMS would work well and should last.

Almost Last : If you get a pair of 12V batteries, then charge them with a pair of 12V chargers. If you get a single 24V battery, then charge it with a single 24V charger. Lithium chargers are available on ebay and amazon. And you probably don't need a huge charger. If you're draining 20A on a trip, then a 5A charger will charge the battery in about 4 hrs. Less charge current = less heat = longer electronics life.

Diet Dept: I've used mine enough that I'm planning to get a 50A battery. A more modern battery pack will weigh about 15 lbs and run about $220 (or so). I like the idea of a lighter pack since I have never used more than 21A to recharge. With that low depth of discharge (40%) I expect the new battery to last 3000+ cycles (ie, the rest of my life). I think its likely you could use a 24V, 50A battery too. Your call...

BILLBYRD1 Loc: Prattville Al

The 36 volts are more expensive but are suppose to have more power and a longer life time. I guess we will see if the promises equal the benefits. I guess I will leave us all in suspense. Later.

Will Beachy Loc: Middlebury,In

Switch from a 27 to a series 29 battery ,I have a 12 volt 50 lb. Minn Kota and run it. slot will get 3yrs. out of mine

Wally West Loc: SW Nebraska

Wow gonna take a while to digest all this info. Hate to admit it but I'm as confused as ever. Guess I was I hoping for is 'What you need is (brand) XXXXX battery, model #xxxx.' Thanks to everyone who took the time to help this electrically ignorant individual. You guys are great! Thanks again

doc alden

The main thing you should get out of all the responses is that the battery must be a deep cycle battery. It must say Deep Cycle on the label. If it doesn't, don't buy it. After that, the next most important thing is your budget. Get what you can afford, whether it's lead-acid, AGM, Lithium-ion, whatever. Just make sure it's a deep cycle battery.

BILLBYRD1 Loc: Prattville Al

Don't know if this will help or make it worse. The 36 Volt Lithium Batteries by Lithium Pros. Steve Kennedy that fishes the Bassmaster Elite Series talked about it in "The Next Big Thing" of Bass Times. Hope it helps and not causing more confusion.

Wally West Loc: SW Nebraska

Have checked out lithium batteries. Dakota Lithium has a 24 volt battery for trolling motors that I'm considering getting when my present batteries wear out. Thanks again everyone

Judge32 Loc: Vidalia, Ga. 30474

Interstate Batteries are my battery of choice.