Onboard charger 1 AGM, 1 lead ? battery health bad..charge is full?

[capeshore]

In complete honesty I'm tired of reading about batteries, chargers etc. Have done a lot and its somewhat confusing with all the options.

I have a starting AGM Exide orbital and a Auto Zone, Duralast standard lead house battery. 26 foot cabin cruiser with shore power.Perko 1/2/both switch..basically a standard 2 battery setup.I pulled the batteries and hooked them up to a tester and the tester said "replace battery" "health bad" They charged up and didn't have any problems during the boating season? The tester shows them having very low CCA yet the charge says full?
have been suspect of my big old 1996 "silver box" onboard charger all season but never a dull light of starting issue.

Can someone suggest a reasonably priced charger that will be good for both batteries? Say under or around $150 ?

 

[Silvertip]

Re: Onboard charger 1 AGM, 1 lead ? battery health bad..charge is full?

It is possible for a battery to show a full charge but the minutr you put a load on it voltage drops like a rock. A battery needs to hold a charge so it current can be delivered to the load. This is why you see the low CCA reading. The battery is no longer able to deliver its rated cca.

 

[capeshore]

Re: Onboard charger 1 AGM, 1 lead ? battery health bad..charge is full?

It is possible for a battery to show a full charge but the minutr you put a load on it voltage drops like a rock. A battery needs to hold a charge so it current can be delivered to the load. This is why you see the low CCA reading. The battery is no longer able to deliver its rated cca.

Thank you for the reply and info. So this would tell me that my charger has not been keeping the batteries charged up enough?

 

[Don S]

Re: Onboard charger 1 AGM, 1 lead ? battery health bad..charge is full?

Or it could be the batteries are junk. Bad battery connections, cables, or cable ends.

Batteries can be load tested, and connections need to be clean and tight (with a wrench, not a wingnut) and the cables need to be in good shape. No loose or corroded terminal ends, they also can't be held on by 1 strand. There is also 2 cables, for each battery. Positive and negative, and each cable has two ends.

 

[capeshore]

Re: Onboard charger 1 AGM, 1 lead ? battery health bad..charge is full?

Or it could be the batteries are junk. Bad battery connections, cables, or cable ends.

Batteries can be load tested, and connections need to be clean and tight (with a wrench, not a wingnut) and the cables need to be in good shape. No loose or corroded terminal ends, they also can't be held on by 1 strand. There is also 2 cables, for each battery. Positive and negative, and each cable has two ends.

Hmm.. both batteries were brand new around April 2012. Went right in boat. I'm suspect of the battery cable ends I guess.They are pretty old. I've cleaned them well but the crimped ends always looked a bit corroded to me.I'm typically very fussy but I let that go.
Wow,just ate two batteries it looks like:facepalm: no money for those right now..

I'll at least load test them and see what it says but the diagnostic machine I'm using is working properly so have to start their.

 

[bruceb58]

Re: Onboard charger 1 AGM, 1 lead ? battery health bad..charge is full?

Charge up the batteries and let them sit for 20 minutes and check the voltage. Should be around 12.6V if fully charged. You let them sit so the surface charge has a chance to dissipate. Then you can load test them to see if they have any capacity.

You do keep your batteries fully charged at all times right? Not doing so can cause the premature battery failure that you are experiencing.

 

[Georgesalmon]

Re: Onboard charger 1 AGM, 1 lead ? battery health bad..charge is full?

you asked about a new onboard charger. I'm using a pro-mariner and am very happy. It will charge different types of batteries and is in the price range you want. Depending on how large you want it to be. Since I'm a weekend boater my pro-8 will charge fast enough for me and of course maintain as well.

 

[capeshore]

Re: Onboard charger 1 AGM, 1 lead ? battery health bad..charge is full?

bruceb58... thanks for the repy.I had thought they were "maintained" by my boat charger. But I'm learning that something in the chain is not right. The boat always started right up? Didn't spend more than an evening out on the hook so not much power getting used.(much longer trips planned for this upcoming season.) So I thought all was ok. My battery gauge on my dash would read just about or under 12 v. when I would get to the boat after say 3-4 days. Thought I was ok?

Georgesalmon... read about the pro mariner's so thanks I like actual people suggesting them than the companys saying how great their products are.

Sorry to complain, but typical boating, test the batteries after the season and wind up with a $600 problem..charger,battery,cables. I'm gonna start with cables and test the system from there.

 

[Silvertip]

Re: Onboard charger 1 AGM, 1 lead ? battery health bad..charge is full?

Just under 12 volts does not make a healthy battery.

 

[bruceb58]

Re: Onboard charger 1 AGM, 1 lead ? battery health bad..charge is full?

Measure them with a multimeter at the battery. The gauge at the dash can be very inaccurate.

 

[capeshore]

Re: Onboard charger 1 AGM, 1 lead ? battery health bad..charge is full?

Just under 12 volts does not make a healthy battery.

What should a battery read or a dash gauge read when a battery is plugged in to the boat charger? What about when it is not plugged in say right after getting to the boat and shutting off charger?
Guys again thanks for the reply's.

 

[Silvertip]

Re: Onboard charger 1 AGM, 1 lead ? battery health bad..charge is full?

It doesn't matter much in either case because those readings again are with no load. A bad battery as we've been trying to explain can measure 12.6 - 12.8 volts. But apply a load and the voltage drops. Have them load tested at any auto store and then go from there.

 

[bruceb58]

Re: Onboard charger 1 AGM, 1 lead ? battery health bad..charge is full?

After a battery is fully charged, it will read 12.6V after the surface charge dissipates. That just indicates that the battery is fully charged and there are no bad cells. Then you load test. If the battery never reaches 12.6, its pointless to do the load test as you have a bad cell.

When the charger is attached, it can read in the upper 13V range depending on how much current is being supplied.

 

[capeshore]

Re: Onboard charger 1 AGM, 1 lead ? battery health bad..charge is full?

Silvertip, Bruceb58.. I gotcha. Thanks. I will go have a load test done. I think I know where this is leading too. I guess moving forward I have one last question.

Once the new charger,batteries, cables etc. get done. What do I want to see from an onboard boat charger as far as the dash gauge and or taking a reading from the battery while the charger is on? Also does leaving my Perko switch to 1/2 or both affect charging? (I will confirm all this with a tester and switching the switch) Just want to know what the norm is.

 

[Don S]

Re: Onboard charger 1 AGM, 1 lead ? battery health bad..charge is full?

Silvertip, Bruceb58.. I gotcha. Thanks. I will go have a load test done. I think I know where this is leading too. I guess moving forward I have one last question.

Once the new charger,batteries, cables etc. get done.

Why are you replacing the batteries and charger? If you haven't had them checked, your spending a lot of money for nothing by using the age old "throw parts at it till it works" method of boat repair. Usually people go broke replacing good parts only to find they had a bad connection.

Do some testing, not replacing.

 

[capeshore]

Re: Onboard charger 1 AGM, 1 lead ? battery health bad..charge is full?

Oh believe me I'm not gonna throw money I don't have Ito it. I just meant once the system is running correctly , new charger, cables whatever it may need what am I supposed to be seeing so I know what a proper gauge and battery should read charging and not charging etc. ?

 

[Georgesalmon]

Re: Onboard charger 1 AGM, 1 lead ? battery health bad..charge is full?

with an onboard charger what you see will depend on if the charger is charging or maintaning. If your on dash gauge is accurate you should never see less than 12.Something vdc. Usually around 12.5ish. If the charger is charging you could see 13 to 13.7ish.

 

[bruceb58]

Re: Onboard charger 1 AGM, 1 lead ? battery health bad..charge is full?

With the charger on, whether its maintaining or not, you will see over 13V. The float voltage is going to be in the 13.3V area.

 

[capeshore]

Re: Onboard charger 1 AGM, 1 lead ? battery health bad..charge is full?

Great , thanks guys. Good to know roughly what I should be seeing as this past seasons "readings" have obviously not been correct.