If you have integrity, nothing else matters. If you don't have integrity,
nothing else matters.
berudd, I was initially asking the question because I was having problems with my Humminbird Helix 9 Mega unit powering off on its own. I was told that the battery was either bad or that it wasn't a big enough/powerful enough battery to run a power hungry depthfinder for extended periods of time. That's why I thought that maybe I would try a deep cycle battery and therefore would certainly have enough reserve capacity to power the depthfinder. After messing around and posting other questions, I figured out that the quick connect connector that I have on my Humminbird was not creating a solid connection and the power cable was wiggling loose just enough to cause the power to go out on it. Now that I have that figured out, I think I'm just going to stay with a starting battery. Better safe than sorry.
Bruce
2019 20 TRX Patriot
Mercury 250 ProXS Fourstroke
HDS 12 Live - Console
HDS 9 Live - Bow
But using a cranking battery with large RC in a way that discharges it heavily puts exactly the same electrical load on the battery as a deep-cycle. The only difference is that a deep-cycle has plates made to take that kind of use while a cranking battery doesn't. Mercury is just flat mistaken on this issue.
If you have integrity, nothing else matters. If you don't have integrity,
nothing else matters.
Yah, I'm sure mercury is wrong, LOL, It is not how the battery is discharging, the problem is how the battery is taking the charge, or how it's not taking the power appropriately which is what the pictures are showing on page 1. If the power has no place to go or not get there fast enough shit is going to happen which is why thinner plates are better in this situation. Can you use a deepcycle to start your motor, yes you can, but I wouldn't let the big motor charge it, see the problem
None of that applies. The pictures show overheating from long, high charge rates, and the charge rate for a cranking battery will generally be higher than a deep-cycle for the very same reason a cranking battery can supply current faster than deep-cycle. I can promise you I know more about batteries and charging than anyone working at Mercury. My batteries run on boats and birds that are a little nastier than anything running a Mercury.
If you have integrity, nothing else matters. If you don't have integrity,
nothing else matters.
So what's the verdict? I'm having the same debate right now...I bought a deep cycle with mca of 810 and cca of 650...
I have used dual purpose batteries now as a starting battery for 19 years and have never had any problem doing so at all. I have a 24 volt trolling motor and I only have 2 dual purpose batteries in the boat. The one battery serves a "dual purpose" and is used for both the trolling motor and for starting 3 different Mercury outboards over the years.......a 200 Promax, a 225X, and a 280 ROS. Like most things regarding boats, there are many opinions out there. This has just been my real life experience.
Depends, what engine are you asking about and does it have a stator style charging system or an alternator? This particular topic has both styles mixed in replies above, so impossible to answer your question. Best to open a new topic for your engine and include the serial number so you get the correct answer.
_______
Phil
'09 Hewescraft ProV
'09 150 Optimax
Dual Mercury Master Technician- for Mercury Outboards, Mercruiser and Mercury Racing at European Marine in Greenville, SC.
Still consider myself a "Marine Apprentice" after 47 years (learn something new every day).
Mercury Parts, Mercury Outboards, Smartcraft & Accessories, Injector Service, TDR Reeds- BBC Sponsor
I understand why Mercury is concerned about the charging system, but I disagree with their solution. The basic problem is that a modern bass boat uses more electrical power than these outboards were designed to deal with. The amount of charging system power required to replace the power drawn from the battery will be roughly the same for a deep-cycle or a cranking battery, though the deep-cycle will probably draw less current for a longer time. The AGM will use less overall power from the charging system because it is more efficient at charging, though it may tend toward higher charging current while it is charging.
My opinion is there are no good solutions. Given the power demands in modern bass boats, telling you not to use a large capacity battery is essentially telling you the motor is obsolete for bass boat use and needs to be replaced. Not untrue, but impractical for many people. I think the better recommendation is to use the battery you need, but keep a close eye on the condition of your OEM-only regulators.
The "Make people happy" solution would be a redesigned regulator that provides maximum current while protecting the charging system from overload, but engineering work on parts for 15 year-old motors is probably not going to happen.
If you have integrity, nothing else matters. If you don't have integrity,
nothing else matters.
I always wanted to ditch the regulators and try one of those Simon's alternator kits, they are 50amp.
1999 ProGator 190V
200 Mercury EFI 0G843298
Those regulators have undergone massive changes since the original design, and are actually quite durable when utilized in a REASONABLE duty cycle.
FULL OUTPUT demand is where the problem lies... and the fact that at best, that full-output is 40 amps.
Dual Mercury Master Technician- for Mercury Outboards, Mercruiser and Mercury Racing at European Marine in Greenville, SC.
Still consider myself a "Marine Apprentice" after 47 years (learn something new every day).
Mercury Parts, Mercury Outboards, Smartcraft & Accessories, Injector Service, TDR Reeds- BBC Sponsor
I use these: Optima Batteries 8016-103 D34M BlueTop Starting and Deep Cycle Marine Battery
So what battery for a 98 mercury 225 efi running two lowrance graphs and other electronic s was looking at interstate 31 agm
Dual Mercury Master Technician- for Mercury Outboards, Mercruiser and Mercury Racing at European Marine in Greenville, SC.
Still consider myself a "Marine Apprentice" after 47 years (learn something new every day).
Mercury Parts, Mercury Outboards, Smartcraft & Accessories, Injector Service, TDR Reeds- BBC Sponsor