East Coast Dave Posted August 2, 2020 Report Share Posted August 2, 2020 So I had some work done on the Pathfinder ( Amp, speaker two new onboard chargers). One of my batteries needed to be replaced I had two cranking batteries . Bought a new interstate cranking battery from Academy. Put on the onboard charger to top everything off and went out on the boat with my wife, anchored with some music playing. Not very long after I notice the voltS on the Gauge looked low.. so I cranked the motor and the Simrad nd stereo shut off. Should I have a normal cranking battery and a deep cycle or dual purpose battery for the house? I didn’t think it would be an issue on a normal cranking battery to run the radio and simrad for as little as a hour without running motor . Thanks Quote Link to comment Share on other sites More sharing options...
MuddyBottomBluz Posted August 2, 2020 Report Share Posted August 2, 2020 Yes, you should have gone with the cranking/deep cycle (dual purpose). BUT, during cranking the motor pulls some serious amps and causes a low voltage condition, no matter what battery and chilling at a sand bar or anchored with no motor running will reduce available voltage fast. Most marine electronics protect themselves in low voltage conditions, typically 11/10.5 or less. Next time turn the battery switch to both, if applicable, and see what happens. Others will chime in, I'm sure. Quote Link to comment Share on other sites More sharing options...
Lap it Up Posted August 3, 2020 Report Share Posted August 3, 2020 Double check all grounds. Also use SS nuts with lock washers on all battery posts. If you use wing nuts make sure to throw them out. Some guys like to run their sensitive electronics on a troll battery or second house for this very reason, but in reality you should not have that kind of voltage drop with a new high percentage cranking battery. Believe it or not a brand new battery will get better after several charge cycles. Keep exercising the battery and your residual voltage should improve. For what its worth... I only have one group 27 dual purpose in my little runabout. It provides crank along with everything else. I can run a 400w amp and 4 JL's for hours and still have plenty of crank power. GPS doesn't blink. Quote Link to comment Share on other sites More sharing options...
Miss Jazzy Posted August 3, 2020 Report Share Posted August 3, 2020 I just went through this same issue as you described. I added a separate dedicated start battery with a blues seas ACR. This setup dedicates one battery to do one job and that’s to crank your motor. All other electronics run off the house battery and it will not allow you to run the cranking battery down. It isolates the two when cranking. But it also uses the outboard to charge both. The starter charges first and when it tops off the house gets charged. Plus if for some reason the starter is dead a flip of the switch and you combine the two batteries. With this setup you will not be stranded. I also found a group 24 marine starting battery that has 1400 cranking amps from the battery source. So putting four batteries in my console was pretty easy. 1 Quote Link to comment Share on other sites More sharing options...
bernieNC Posted August 3, 2020 Report Share Posted August 3, 2020 Assuming you purchased a 27M-XHD.? It has a a RC of 182 so that should not be the problem. I use this battery and just switched it out after seven years. Everything but the TM runs thru it and never a problem. One of the TM batteries is wired as a back up (#2). Stealth AC/DC!!! Quote Link to comment Share on other sites More sharing options...
Wanaflatsfish Posted August 3, 2020 Report Share Posted August 3, 2020 I run my SIMRAD off one of the TM batteries....I had the same problem over and over and would loose my distance(TRIP) function each time and have to restart - real PIA. So, with direct wire with a fuse in line....no more problems. Everything else runs off the house interstate wet cell and it works well. DC Quote Link to comment Share on other sites More sharing options...
East Coast Dave Posted August 4, 2020 Author Report Share Posted August 4, 2020 On 8/3/2020 at 8:11 AM, Lap it Up said: Double check all grounds. Also use SS nuts with lock washers on all battery posts. If you use wing nuts make sure to throw them out. Some guys like to run their sensitive electronics on a troll battery or second house for this very reason, but in reality you should not have that kind of voltage drop with a new high percentage cranking battery. Believe it or not a brand new battery will get better after several charge cycles. Keep exercising the battery and your residual voltage should improve. For what its worth... I only have one group 27 dual purpose in my little runabout. It provides crank along with everything else. I can run a 400w amp and 4 JL's for hours and still have plenty of crank power. GPS doesn't blink. I will double check and report back. I wanted to have a backup cranking battery just in case but didn’t think running 4 JLs and an amp would run things down that quickly. Something is not making sense. I remember others mentioning previously the voltage drop due to low or bad battery would cause the simrad and radio to turn off when cranking. The guy load tested all batteries (3 trolling and two cranking) and singled one out as being bad. I wish I could take a crash course on boat wiring and batteries to understand this stuff better. I get pretty frustrated with it. Quote Link to comment Share on other sites More sharing options...
Bever Posted August 10, 2020 Report Share Posted August 10, 2020 EastCoastDave, check out this free marine wiring series. Much of this guy’s info is geared towards boats with multiple banks of batteries and AC current as well as DC for the big yacht systems, But he covers theory that applies to What we are doing also. He covers switches, battery selection and maintenance, connectors and wire size, battery combiners and isolators w/ parts on ACR use as well. He covers switched and direct wires as well as using the DC/ohm meters. It’s well worth the time. Quote Link to comment Share on other sites More sharing options...
Headhunter Posted August 11, 2020 Report Share Posted August 11, 2020 Dave, Had the voltage drop when starting on the Maverick. The Garmin would say low voltage when the engine cranked. I found a loose connection at the dash where the positive would go from one breaker to another. The loose connection was "down the line" from the gps connector. Once I crimped it down no more issue. Good luck! Quote Link to comment Share on other sites More sharing options...
scseadog Posted August 11, 2020 Report Share Posted August 11, 2020 I just picked up one of these for peace of mind as I only have one cranking/house battery- NOCO Boost Plus GB40 1000 Amp 12-Volt Ultra Safe Portable Lithium Car Battery Jump Starter Pack. Any feedback on these? Quote Link to comment Share on other sites More sharing options...
DonV Posted August 11, 2020 Report Share Posted August 11, 2020 Dave, I may have missed it, however you did not mention what amp you have for the speakers. Might want to check the amp draw on that stereo amp, it can be pretty high. My brother had the same problem when he installed a mac daddy amp and had to up size to a large DC battery versus regular starting. Quote Link to comment Share on other sites More sharing options...
bernieNC Posted August 11, 2020 Report Share Posted August 11, 2020 2 hours ago, scseadog said: I just picked up one of these for peace of mind as I only have one cranking/house battery- NOCO Boost Plus GB40 1000 Amp 12-Volt Ultra Safe Portable Lithium Car Battery Jump Starter Pack. Any feedback on these? They are GREAT. I have a GB50 and just used it during/after hurricane to keep the cell phones charged during power outage. Have used it multiple times in the past for jump starts on all kinds of stuff. ie trucks, cars, outboards, riding mowers, and tractors 1 Quote Link to comment Share on other sites More sharing options...
smilemaker Posted August 11, 2020 Report Share Posted August 11, 2020 the amount of draw from an amp will vary with volume and the notes. take a look at some poorly designed stereos in cars at night. when the big bass hits their headlights will dim. it's not the number of speakers but what are they drawing. 1 Quote Link to comment Share on other sites More sharing options...
East Coast Dave Posted August 13, 2020 Author Report Share Posted August 13, 2020 On 8/11/2020 at 9:26 AM, DonV said: Dave, I may have missed it, however you did not mention what amp you have for the speakers. Might want to check the amp draw on that stereo amp, it can be pretty high. My brother had the same problem when he installed a mac daddy amp and had to up size to a large DC battery versus regular starting. Nothing real crazy. Two 6.5 s and two 7.7 with a 400 watt amp. Quote Link to comment Share on other sites More sharing options...
polliwog Posted August 16, 2020 Report Share Posted August 16, 2020 'll add my support for a Lithium ION battery jumper. They are super small and will start almost anything, like my diesel SUV 3.0 V6.It's called peace of mind. Never leave port without mine. 1 Quote Link to comment Share on other sites More sharing options...
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