Welcome, Guest
Username: Password: Remember me
  • Page:
  • 1

TOPIC: optima yellow top battery performance??

optima yellow top battery performance?? 21 Jun 2009 00:28 #1

  • BrooklynJim
  • BrooklynJim's Avatar Topic Author
  • Offline
  • Elite Member
  • Elite Member
  • Posts: 531
  • Thank you received: 0
i need your opinions here fellas


my intentions are extended times on the batteries, i.e.. overnight and into morning hours, 17" widescreen LCD/DVD player will be playing most likely all night since i fall asleep with it on, and possibly another 15" if i have guests, and in the morning the coffee pot to make 12 cups is pretty much the extent of the draw on the inverter, so im thinking 2k watts/4k surge should be adequate, maybe even a smaller 1500/3000 surge

the batteries performance stats are:

Open Circuit Voltage (Fully charged): 13.1 volts
Internal Resistance (Fully charged): .0028 ohms
Capacity: 55 Ah (C/20)
Reserve Capacity: BCI: 120 minutes
(25 amp discharge, 80°F (26.7°C), to 10.5 volts cut-off)

so if im not mistaken, the reserve capacity at a 25 amp draw is 2 hours, so... if i combine 4 batteries i would effectively get 8 hours at a 25 amp draw? is that correct? and if so, at a 15 amp draw would get the better side of 10 hours?

should i....

a) run my 4 optima 34/78 yellow top house batteries (largest size avail) and just combine them after starting? using seperate starting batteries ofcoarse, will they last all night?

b) or just use the 4 as they are currently wired 2x2 and wire in my magnum auto start system that watches the battery voltage level and auto starts the engine if drops below 11.2 volts, its actually intended to auto start a genset, but ive had it wired to a main engine before for the same purpose with good results, this ofcoarse requires a seperate, isolated starting battery

im into these batteries for $800 and have had good experiance with them, no matter how long the boat has floated unattanded the batteries always had good starting performance, even after weeks just sitting there, and even powered the 2 x 55watt floods for 4 hours, but i was awake during all these and watched the volt meter like a hawk, dont want to wake up to a dead ship, not so much cause ill be stuck, cause the coffee pot wont be able to brew.. hehe :hammer

unless you guys have a better recommendation so i can live off the batteries for extended times??

also, im planning on mounting them as well as the inverter far forward in the bow under the bed in a cabinet for weight distribution, and using the proper cabling ofcoarse, i can use a standard 2/0 or 1/0 to run a charge lead to the batts from the engines correct?

Please Log in or Create an account to join the conversation.

Bayliner 3270
"MARAKI"
Twin Crusader CH220's
(repowered)
Important Notice"
DUE TO RECENT BUDGET CUTS, STOCK MARKET PERFORMANCE, RISING COST OF ELECTRICITY, GAS AND OIL...
THE LIGHT AT THE END OF THE TUNNEL HAS BEEN TURNED OFF....
WE APOLOGIZE FOR THE INCONVENIENCE
Regards
THE GOVERNMENT
[/SIZE]

optima yellow top battery performance?? 21 Jun 2009 01:40 #2

  • ishiboo
  • ishiboo's Avatar
  • Offline
  • Administrator
  • Administrator
  • Posts: 3134
  • Thank you received: 21
IMHO, I'd get two cheap(ish) starting batteries and use the yellow tops for the house bank.

Using the house batteries to start located on the other end of the boat will require some STOUT cables which are going to be $$. As a cheaper alternative, if you were JUST using them as house and didn't need to be able to switch live to start off them, I'd run smaller cable (8-10ga) and a battery isolator just for charging from the alt. You could always pop one out and connect it in the engine compartment if the need arises.

How does the magnum auto generator start operate the blower for 4 minutes before the engine starts? If you haven't considered this, you're going to blow yourself up sooner than later :)

Please Log in or Create an account to join the conversation.

2005 Crownline 316 LS "The Lucille"

optima yellow top battery performance?? 21 Jun 2009 01:41 #3

  • ishiboo
  • ishiboo's Avatar
  • Offline
  • Administrator
  • Administrator
  • Posts: 3134
  • Thank you received: 21
BTW now that I think about it 8ga may be too small depending on your charging amps, use the chart for figuring out what the correct value would be.

Please Log in or Create an account to join the conversation.

2005 Crownline 316 LS "The Lucille"

optima yellow top battery performance?? 21 Jun 2009 02:45 #4

  • BrooklynJim
  • BrooklynJim's Avatar Topic Author
  • Offline
  • Elite Member
  • Elite Member
  • Posts: 531
  • Thank you received: 0

ishiboo;312592 wrote: IMHO, I'd get two cheap(ish) starting batteries and use the yellow tops for the house bank.

Using the house batteries to start located on the other end of the boat will require some STOUT cables which are going to be $$. As a cheaper alternative, if you were JUST using them as house and didn't need to be able to switch live to start off them, I'd run smaller cable (8-10ga) and a battery isolator just for charging from the alt. You could always pop one out and connect it in the engine compartment if the need arises.

How does the magnum auto generator start operate the blower for 4 minutes before the engine starts? If you haven't considered this, you're going to blow yourself up sooner than later :)



my magnum starting system has a programmable (switchable on/off) prestart circuit thats suppose to be used for a diesel glow plug circuit, it supplies power to glow plug relays before engaging the starter, i split that lead to 2 standard spst automotive type relays to power both the blowers for 50 seconds, (max/programmable prestart threshold) awesome little unit

any idea what kind of performance i can expect from the batteries using them like this? all 4 are 1 month old

Please Log in or Create an account to join the conversation.

Bayliner 3270
"MARAKI"
Twin Crusader CH220's
(repowered)
Important Notice"
DUE TO RECENT BUDGET CUTS, STOCK MARKET PERFORMANCE, RISING COST OF ELECTRICITY, GAS AND OIL...
THE LIGHT AT THE END OF THE TUNNEL HAS BEEN TURNED OFF....
WE APOLOGIZE FOR THE INCONVENIENCE
Regards
THE GOVERNMENT
[/SIZE]
  • Page:
  • 1
Moderators: Jim GandeeRuffryder
Time to create page: 0.080 seconds
Powered by Kunena Forum