size of battery bank original design

Feb 27, 2013
9
I have a 2002 Hunter 340 my original batteries have been changed out to optima's my boat yard doesn't like these.. I had purchased these in the last 8 months now have starting problems. I am going to replace them with Deko as to boatyard recommendations. My question is what were the original size of batteries. I will bump up a size but want to pair the charger with batteries. Because of all the upgrades on boat and I have read that the optima's can be problematic if the charger throws too much power to them.
 
Feb 6, 1998
11,715
Canadian Sailcraft 36T Casco Bay, ME
I have a 2002 Hunter 340 my original batteries have been changed out to optima's my boat yard doesn't like these.. I had purchased these in the last 8 months now have starting problems. I am going to replace them with Deko as to boatyard recommendations. My question is what were the original size of batteries. I will bump up a size but want to pair the charger with batteries. Because of all the upgrades on boat and I have read that the optima's can be problematic if the charger throws too much power to them.
Your boat yard is feeding you a line of BS, or they really are that ignorant.......

Your starting problems are most likely:

*You are under charging the batteries
*You have wiring issues

An Optima should EASILY start your motor. This is what Optima Batteries do best.:doh:

#1 The original banks size means nothing. Your bank should be sized for your use. Nearly every boat builder out there throws horribly undersized banks into boats in order to save money.

#2 Optima's are good quality batteries, though not as good as they used to be now that EnerSys sold the brand off to Johnson Controls (JCI). That said orbital/spiral batteries pack less Ah capacity per sq in of foot-print that flat plate batteries do. This is why they don't make great house bank batteries and you need more of them to do what you need.. For example an Optima Blue Top Group 31 is a 75Ah battery but a Lifeline GPL-31XT comes in at 125Ah in the same BCI case group size. That is 50 more Ah's in the same exact foot print! Optima batteries csot more per Ah than other AGM's.

Optima Blue Top Group 31 AGM = $3.98 Per Ah
Lifeline GPL-31XT AGM = $2.90 Per Ah

The Lifeline is also a premium quality AGM...

#3 I understand the yard sells Deka. If you are sticking with AGM Lifeline and Odyssey are the two premium AGM brands.

You may want to read this before making any decisions: AGM Batteries - Making The Choice

#4 The size of your existing charger should not dictate what size bank you have but if you are sticking with AGM batteries then you really need a charger designed for AGM's. AGM batteries should have temp compensated charging.

#5 You will not "overcharge" your batteries unless the voltage settings are incorrect. The current flowing into the battery is determined by the battery, not the charger. Voltage is what kills VRLA batteries (valve regulated lead acid batteries) not current.

When you read that above link be sure to read the manufacturers cycle life data for Deka AGM's...
 
Feb 27, 2013
9
holy cow now I am really confused……. I do not use the house batteries cause we don't camp on our boat unless we are parked at a dock. I have no problems right after I put the optima in for 15 months. They went to the dock to start one day after we had left the house bank on and it died. Tried the starter battery and all went fine. Then a month later went to start motor on starter side and dead. Switched to house bank and not enough juice. I have replaced all battery cables before the new optimas because we were having starting issues and because found them to be full of green fuzz. Put in a starter solenoid which allows a spinning of the system to start but no success unless I use both banks. I am told once to optimas go dead they never return to full power.
 
Feb 27, 2013
9
how do I tell the voltage coming out of my charging system??? I have no idea what type of batteries were original AGM? wet?? gell?? no I am not sure what my charging system is built for
 
Feb 6, 1998
11,715
Canadian Sailcraft 36T Casco Bay, ME
how do I tell the voltage coming out of my charging system??? I have no idea what type of batteries were original AGM? wet?? gell?? no I am not sure what my charging system is built for

#1 Can you get us a photo of your charger or brand and model #?

#2 We really need to know how your charger is wired? It could be that it passes through the battery switch and that switch directs which bank is being charged.

Best to use a DVM with the charger known running/on and measure the terminal voltage at each battery bank..

Set it to BOTH > Measure voltage of both banks (this will confirm BOTH position is working and both banks should have same voltage reading.)

Set it to BANK #1 > Measure voltage at both banks

Set it to BANK#2 > Measure voltage at both banks

Set it to OFF > Measure voltage at both banks
 
Aug 29, 2014
11
Hunter 340 Bellingham
Optimas were all the rage in the Porsche world a few years back. I put one in my 911 to save weight and it died after two years. Not a big fan.
 
Feb 27, 2013
9
I will get the name but I do know there are lights that say invert/wet, charge/gel 1, overtemp overload/ agm, low battery/ gel2. The brand is red script looks to say Freedom marine 10 1000 wats. 60 amp charger…. heart interface combi inverter/charger