I have a 2016 521 with a 250 Evinrude. I was having issues with my starting battery dying too quickly so I replaced it with a stronger Duracell Platinum AGM. Issue is still there. Yesterday with running the livewells on high, back hd12 on standby, and front hd12 running, we were having to jump start the boat by 11 and the battery was so dead by 1 the graph wouldn't even work. Any ideas what's going on? Is their something else that might be pulling on it? Thanks in advance!
Click on the Search button at the top of this sheet. Then type in batteries....this is an outstanding starting point.
Are you sitting in one spot all that time and not running? Plenty of others have had problems similar to yours, but not that extreme. The best advice I can give you is to check the reserve capacity of your battery and get as strong a one as you can. I'm rnnng a similar setup, but my front graph is only an HDS-9 and I usually run the livewells on low rather than high. By 1 p.m., if I'm not running much, my battery voltage may drop to mid-11s, but no lower. I have a series 31 Deka AGM. And have never had a minute's trouble starting the engine. Sometimes I can fish and run livewells on timer for 6 hours or so and never run a mile, so either your HDS-12 uses a lot more voltage than my 9 or your battery is weaker.
John Clark — Findlay, Ohio
What's the specs on your battery?
2017 Ranger Z520c "Blackout Edition"
2017 Mercury Optimax ProXS 250
HB Solix 12 G3 MSI+, Solix 12 G2 MSI+, Solix G2 MDI+, Solix 12 2d/gps, Ultrex Mega360, Mega Live
NRA Life Member
-Be sober, be vigilant; because your adversary the devil, as a roaring lion, walketh about, seeking whom he may devour-
Check the voltage on your battery after a full charge and at least 6 hrs to stabilize. You might not be getting a full charge.
Anyone lettng their lead acid batteries discharge to mid 11s (volts) is killing their battery's normal life.
Stop and recharge at about 12.2-12.3 volts or around 50% capacity for obtaining normal battery life. If that is too early in the day, you either buy larger batteries or cut back on their loads unless you are fine with regularly replacing overdischarged batteries.
Last edited by Lou r Pitcher; 05-28-2017 at 07:58 PM.
The AGM batteries I use don't seem to have any ill effects from dropping slightly below 12 volts on my Lowrance readout, as I routinely get 4-5 years without noticeable power loss, but I'm not extremely confident in those Lowrance readings anyway. The display might show 11.7 volts when I slide into the driver's seat, then jump to 13 volts within 1 minute of idling to the next spot. Not trying to open another can of worms on the OP's thread, though....Originally Posted by Lou r Pitcher
John Clark — Findlay, Ohio
Lowrance units cannot show the battery voltage unless owner has added a NMEA-2000 voltage sensor at the battery. They only can show supply voltage.
As for discounting the effects of over discharging a battery, the graphs/data are often available directly from the battery manufacturer showing the actual degradation of their battery life at various discharge levels.
Last edited by Lou r Pitcher; 05-30-2017 at 12:19 AM.
The specs on it...
1 amp hour rate:68.2100 amp hour rate:110
20 amp hour rate:105
3 amp hour rate:85
5 amp hour rate:86
6 amp hour rate:87.4
8 amp hour rate:90
Battery Electrolyte Composition:Glass Mat
Battery End Type:Top Post
Battery Purpose:Starting Lighting Instrumentation
BCI Group Size:31
CCA at 0 degrees F:800
Freight Class:65
MCA at 32 degrees F:1000
Minutes at 15 amps:348
Minutes at 25 amps:210
Minutes at 5 amps:1265
Minutes at 50 amps:87.4
Minutes at 75 amps:53
Minutes at 8 amps:706
Polarity:Left Positive
Reserve Capacity:200
Terminal Type:STUD/SAE
Volts:12
Based on some testing today on the water... Each graph pulls 2.2-2.3 amps each and livewells while running pull just over 6 amps.
Your battery charger may not be up to the needs for AGM batteries. Check this first. Odyssey has a list for suggested battery chargers for their AGM batteries. While you are on their site odysseybattery.com click on "marine batteries" and at the bottom of this page click on "marine battery specs" and compare your battery specs to the odyssey 31M-PC2150. These are great batteries when used with the appropriate battery charger. My set of four (one for cranking and acess. and three for the trolling motor) have lasted seven years now. I am sure they will go out any day now, but no sign of letting up yet. I would guess it is your battery charger.
From your numbers, you are pulling around 10-11 amps continuously And your battery specs shows it is considered fully discharged at that rate draw after about 500 minutes .But you can not repeatedly expect to discharge it fully as it would soon fail.Based on some testing today on the water... Each graph pulls 2.2-2.3 amps each and livewells while running pull just over 6 amps
The battery when new should have provided safe repeated discharges to 50% capacity or around 250 minutes......a bit more than 4 hours if it was not losing/gaining net charge cranking the outboard. Toward a normal end of battery life any battery should provide about 80% of its new capacity so you might expect about 3.2 hours of use before it would require recharging (if the outboard is not affecting it.)
Last edited by Lou r Pitcher; 05-30-2017 at 12:20 AM.
Rangers eat batteries, and I feel its mostly the live well pumps. They run alot even in timer modes. The only battery thats held up for me in a tourny days fishing is the PM-1 diehard, which is an odessy 2150. I charged with a minn kota 460 pc on the agm setting. No problems at all with that combo.
I bought this battery,
Odyssey 31-PC2150S Heavy Duty Commercial Battery
So far it has held up very well. Fished the other night from 7:30pm to 10:30am the next morning and still going strong. Running two Solix 15's and livewells, Talons etc. I have a Stealth One charging system and cannot say enough good things about it. Since I put it on, no more battery issues.
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