Have a '86 C30 repowered with a Yanmar 2GM... currently Interstate lead acid start and house banks. When leaving Sunday I noticed the start battery is dead (4V). Current lead acid is 7 years old and gets used infrequently (currently), what is a good recommendation for a new one? Group 24? G27? I did not record the size and I'd like to bring one with me this weekend to replace (city pricing vs marina pricing).
C30 start battery recommendation
- Thread starter lunasea6
- Start date
Have you done the cockpit rewire? can't remember when the wiring changed. Details are fuzzy but available online. But the older wiring had a main current wiring travelling to the cockpit. Also need to eliminate "gummy" plugs (one in the motor bay and one behind the cockpit panel)
I'm in a powered slip but leave unplugged to preserve zinc as my dad did. I try to make a monthly trip to charge batteries. Have considered a small solar but wasn't sure that was a good idea with lead acid. Will look more into that. Pretty sure the bilge pump is run off the main/start battery. I really wish I grabbed a better shot of the batteries when I was down last weekend.
I suspect your lead acid battery perished due to low fluid level. Do you check the fluid level every six months and add distilled water to above the plates?
Here is what I did
mei1970.org
You can use solar panel to keep lead acid batteries topped off and extend its life. The charger has settings for lead acid battery that you can select. It will enter into float mode when fully charged at 13.8 v.
Here is what I did
Solar Panel | Sail La Vie
MaineSail recommended a deep cycle instead of a starting battery. Tons of info on batteries and solar on his website marinehowto.com
A group 24 will start the engine fine. A deep cycle group or 31 gives more flexibility to use it for house loads if needed.
All lead acid batteries like sitting at a full charge. A small solar panel with a controller can help with that, or you could keep the boat plugged in and add a galvanic isolator to comfort your zinc concerns.
All lead acid batteries like sitting at a full charge. A small solar panel with a controller can help with that, or you could keep the boat plugged in and add a galvanic isolator to comfort your zinc concerns.
Seven years is pretty much the end of life for a Lead Acid battery. Stay with a flooded lead acid if the battery will be left at a partial state of charge, they are more tolerant of this condition than an AGM battery. AGMs want to be kept fully charged, if not they can die soon.
A "starting battery" is not needed, a battery to start the engine is. It can be any size from Group 24 up. Batteries marketed as deep cycle marine will have more lead and bit more capacity than batteries marketed as marine starting batteries. The deep cycle batteries will start your engine just fine.
A "starting battery" is not needed, a battery to start the engine is. It can be any size from Group 24 up. Batteries marketed as deep cycle marine will have more lead and bit more capacity than batteries marketed as marine starting batteries. The deep cycle batteries will start your engine just fine.
I bought the most expensive FLA battery they had at Autozone. It had higher capacity than all others and has lasted six years so far. It's proven to be a substantial savings over other batteries. Would a higher capacity battery provide a significantly longer life in the marine environment?
Depends. Battery life is a function of several factors. Big ones are number of charge/discharge cycles, depth of discharge (DOD), and time at a Partial State of Charge (PSOC).
The fewer cycles the battery experiences per year, will increase the number of years the battery will last. A battery that sees 100 cycles per year fail sooner in years than a battery that sees 10 cycles a year, although bot h may may experience 300 cycles in their life span.
Batteries left in PSOC for long periods of time will sulfate more and this will reduce the number of cycles the battery can deliver. AGMs are especially sensitive to this.
Batteries live longer if they are kept at a full charge.
Batteries used only for starting can be a bit deceptive. The critical function for a start battery is not the size, but the ability to deliver a high current for a short period of time. It only takes about 1 ah to start small diesels, however, that current is delivered very rapidly, about 250a for a few seconds. Because of this a start battery may still start an engine, even while it has lost a significant amount of its capacity. As a result they may seem to last more seasons than a heavily used house battery.
That does appear to be true, at least in my case.
My start battery is a Group 31 Excide FLA that supposedly was a couple of years old when I bought the boat in Nov 2017.
I installed a Dual Circuit Plus switch so that battery is isolated to just starting service. It's charged using an ACR from Blue Sea.
We mostly day sail so the batteries get charged almost every night.
Just finished our 7th season with the boat and that 9 or more year old battery still starts the engine just fine. I'll probably replace it in the spring with another Gap 31 as it is a back up to the house bank if ever needed.
