AGM batteries

[lawman]

It is time to replace my starter battery and 2 troller batts. Was thinking about AGM batteries. Are they worth the extra money? I run my electronics off the starter battery and need a battery that re-charges on the water quicker as I run between fishing spots.

[Cheers]

Not sure on the charging time but my experience with them was that they last 2xs as long as regular batteries but cost 2xs as much so where not cost effective.

[meathunter]

Before i used agm i would toast one battery per year mostly from big water chop im on year 4 with the set i bought. Cabelas brand

[ClownColor]

Over 6 years and 5 years on my agm's. Thought I'dhave to replace one this year but it still ran great!

[Whoaru99]

I don't believe an AGM battery will give any advantage regarding (reduced) charging time.

[smalliehunter]

I run 4 batteries in my boat. 3 for trolling, 1 for starting and electronics, by the end of an 8 hour tournament day, and running the live well all day my starting battery would be dead. Would an AGM battery help with my problem?

[ClownColor]

Yes...but any decent starting battery should not be dead in that scenario. Also make sure you have an accessory kill switch so your battery isn't half dead before heading out.

[Savage Brewer]

Your problem with the battery being dead has to do with reserve capacity.

If you have a Standard battery with a RC of 100 and a AGM with a RC of 100, theoretically they would perform the same when it comes to the drain when a constant load is placed on the battery.

A couple of suggestions, watch the voltage on your depth finder and when it drops below an acceptable voltage start your main engine and let it charge for a while.

Does your livewell have a timer? try cycling it on a timer so its not running 100% of the time. Also what other accys do you have running off your cranking battery that draw current?

I guess on another note, how old is your cranking battery, its size, and what kind of motor do you have.

A battery's RC will diminish over time, and if your battery is a bit on the small size for turning your engine over, you may need to upgrade to a battery with a larger RC.

The RC is how many minutes a fully charged battery can discharge 25Amps of current at 80 degrees Fahrenheit.

Some Class 24 batteries only have a RC of 70 to 90, there are better ones out there that approach 130 to 140.

Most Class 27 batteries have a RC of at least 160.

Also discharging your battery below 10 volts repetitively will reduce its RC. This is the only area where an AGM will have a benefit, it seems that AGM's recover better from a discharge.

But with that said once discharged the AGM will not do you any good either.

A friend of mine had a similar problem with a Class 27 not being big enough to run accessories and then kick over his 200 Opti, so we went with dual Interstate 24M-XHD in parallel (12 volts) which gives him a RC of 270 and a CCA of 1600, not a single problem since.

[Whoaru99]

^^

+1

[smalliehunter]

i also have a 200 opti. battery was new this year. was out yesterday for only 6 hours and battery was almost dead. when i turned my mototr on it shut both my graphs off. i tried the livewell on a timer with the same results. i have room for another battery. i think i will try an AGM battery at the start of next season.

[delcecchi]

i also have a 200 opti. battery was new this year. was out yesterday for only 6 hours and battery was almost dead. when i turned my mototr on it shut both my graphs off. i tried the livewell on a timer with the same results. i have room for another battery. i think i will try an AGM battery at the start of next season.

What was running during the 6 hours?

[Savage Brewer]

Also what battery is in there?

Those big engines need some current to flip them over, and as the temps drop your battery loses some of its ability to supply the current needed.

Hate to say it, alot of times they try to throw a single class 24 starting battery back there, and it isnt enough.

Plus I see you are running a Humminbird 1198 on there, that finder alone pulls a couple amps.

So lets say you run dual finders, and we push to a constant 5 amp draw, running that for 6 hours and no charge from the main motor. It is conceivable that the battery is just undersized.

It all goes back to Reserve Capacity, temperature can affect that.

Also do you fire up that Opti 200 for 5 minutes to run to the next spot and just shut it down? The Opti will pull more to fire it over than will be replenished in that 5 minutes running.

I normally make sure I run the engine for more than 15 minutes after each start, even if it means its sitting back there idling.

Can you pull the brand, model, size and age of your current battery that is dying?

[delcecchi]

Yeah, that's why I asked. I ran one live well pump overnight on intermittent to keep some minnows alive last summer and in the morning the motor wouldn't turn over. First that ever happened to me. (I don't normally run the live well pump that much)