505 cranking amp batt tests at 289 cranking amps. What do I do

[4pwr]

Took my boat battery to auto store I trust. They put it on the whatever they use to test batteries. Told me it tested out at 280 cranking amps. The battery is rated at 505 cranking amps. I am 205 cranking amps short of the potential of the battery. Does this mean at a 2 amp charge rate I have to carge the battery for 102 plus hours to get the battery up to spec? I guess Iam asking at 2 amp.4 amp,6 amp,10 amp,or whatever,how do I know my battery is fully charged. I am scared to death of drifting into the shipping channel on st.clair river trying to start my boat and it will not start because it does not have enough ooph to do it.

[Eastern Yooper]

Ahhhhmmmmmmmm, maybe its time to spend $75 and get a new battery.......

[ESOX]

:yeahthat:



Or buy boat tow insurance,make certain your radio and antenna are the best you can afford, and never leave sight of shore. Don't forget to charge the cell phone batteries before you leave.

Seriously, I won't use a battery as a crank battery that tests less than 85%, and thats with more batteries aboard to jump one from if need be.

[ESOX]

BTW was the battery properly charged before the load test?

[Eastern Yooper]

A cranking battery will generally last 5-6 years, and then it should be replaced. Dunno how old yours is, but it sounds like you need a new one.

As far as properly charging goes, I'd suggest investing in an on-board charger. A 3-stage, two-bank (capable of charging two batteries at the same time) costs about $100. It easily installs on your boat, and to use you simply plug-in with an extension cord.

It will properly & automatically charge your battery, and will not "overcook" it. While charging, a "red" light will show, and when fully charged a "green" light will appear.

[ESOX]

Very true, 5-6 years for a crank battery is quite common, on boats with a dedicated crank battery. I am beginning to wonder.....charge system and draw down check might be in order.

[Eastern Yooper]

Same thing I'm thinking.

Cranking battery shouldn't be draining like that, unless (a) alternator is going bad, or (b) there is a pile of accessories hooked up to it and the alt is too small to handle it all.

[4pwr]

Battery is 3 years old. Battery was not fully charged. I guess I was asking how do you fully and properly charge a battery?

[lkmifisherman]

Just an idea but why not invest in a battery switch and a second battery as well....I never leave the dock without 2 fully charged batterys onboard... You might even find the 3rd one if you look real hard...Most alternators do not put out their full potential at trolling speeds...and with all the electrical gizmos we have to have today, they don't keep up...

lkmi

[trout]

I just took a battery back to Auto Zone and they replaced it free.
No questions at all!

[Eastern Yooper]

Battery is 3 years old. Battery was not fully charged. I guess I was asking how do you fully and properly charge a battery?

Go to Wal-Mart and buy a "fully automatic" battery charger. Costs under $50. It will properly charge your battery, and when its gets to the 100% charge it will maintain, and not overcook.