Battery problems with my 8d(39)s-gctid356523

[Guest]

Well i guess I should have seen this coming!

I have 4 8d batteries joined in a series and hooked up to my new Xantrex 40 amp charger, with a combine button next to the ignition.

The batteries are just now approaching 2 years old. Amazingly I do not have shore power at my dock and the only thing keeping my batteries charged is my charger, when the genny is running.

So I always run the genny for an hour or 2 or 3, when im out and sometimes at the dock when im not going out.

This has worked far longer than I thought it would but recently, the port engine has been taking a little longer to start, turning over slooowly.

Now I waited 2 weeks to start her up and BOTH engines are not turning over. So today I got my little charger out, hooked it up for (fast charge) 10amps and let each of the first 3 batteries

charge for a little over 2 hours each. I just wasnt patient enough to charge the 4th battery, since it was getting dark.

Nothing! Both engines turned over very slowly and then, click, click, click!

So I guess the next step would be to isolate each battery and go buy a battery tester or meter?

See how all 4 test and which ones, if not all of them, need a real good charge?

I have always checked the water level every 4 or 5 months, so i know its not that.:surr

Any suggestions would as always be greatly appreciated.

Just dont have the money anymore to call my old boat electrician.

Thanks!:surr

Ed

[mmichellich]

I hope you have the batteries in parallel not series.

[LTCret]

I have not done any calculations, but I believe you would need a MUCH larger charger to keep 4 8D's fully charged with the random generator time you have been doing.

It sounds like you have one 4 8D bank being used for house and starting functions?

Can you give us more information on how you are using the boat? Do you cruise long enough to have the engine alternators top off the batteries before you put the boat away? The alternators on my 88 are 65 amps each. How are the alternators tied into the battery system?

More info will get you better advise. There are some real 12 Volt guru's on this forum.

Good Luck

[jmcannonball]

Reading your post - "I have 4 8d batteries joined in a series" - means you are producing 48 volts. Hopefully you meant "in parallel" where you would be producing 12 volts. Charging those 8d's takes a bit longer than group 27's, so a couple hours might not have made much difference. Also, if you did not completely disconnect each battery, your 12v 10amp charger was probably just "whistling in the wind".

Unfortunately, the voltage on batteries hooked in parallel will always sink to the weakest battery in the chain. Here is a simple diagram to show how to properly connect batteries in parallel. Note that one lead to the charger goes from one end of the parallel lineup (in this diagram the positive) and the other lead goes to to the other end of the lineup (the negative).

http://batterytender.com/resources/connecting-batteries-chargers.htm#answer9

Hope this helps.

[kwb]

Simple answer - batterys have never been recharged with the amount of time you have described for recharge timeframe.

Bad news is that they have been down for so long that they are probably toasted.

Your 10A charger would need to run for almost a full day to recharge a single 8D from 0 (that is if it could get it to take a charge in the first place).

If you have no shorepower - I would suggest either automatic generator startup or a solar array to help keep your batteries charged between visits to the boat.

[Guest]

No, I'm sorry I did mean "in parallel". I do know that they are hooked up properly. The electrician that did the install for me knows what he is doing and i do remember, out of curiosity, checking the diagram that came with the xantrex manual. it shows the exact layout for multiple batteries, similar to the diagram jmcannonball linked to.

""I have not done any calculations, but I believe you would need a MUCH larger charger to keep 4 8D's fully charged with the random generator time you have been doing.

It sounds like you have one 4 8D bank being used for house and starting functions?""

I know the charger is probably not strong enough and was just affordable enough at that time. i remember the electrician telling me it was boarderline and that i better get some [power out here so they can get enough charge time.

""Can you give us more information on how you are using the boat? Do you cruise long enough to have the engine alternators top off the batteries before you put the boat away? The alternators on my 88 are 65 amps each. How are the alternators tied into the battery system?""

My typical cruise is only about 2-3 hours, 2 or 3 hours with engines off and 2-3 hours back. i know thats probably not close to enough time to charge so many batteries.

I dont know how many amps my alternators are(or how to check?) and i will check tomorrow to see where they hook up.

I do know that I have a guage with 3 settings that show me a.) amperage of engine batteries, b.) amps of house batteries and c.) amps of genny battery

If they are "in parallel" i dont understand how it could do that!?

""Also, if you did not completely disconnect each battery, your 12v 10amp charger was probably just "whistling in the wind".""

I know i should have disconnected each battery before charging with that little 10amp. i dont know, i was just annoyed, it was hot, that was stupid.

Im thinking tomorrow I will borrow a friends good charger, i dont know how strong, but i know its a good charger(its on wheels!).

I will unhook each battery, use my new tester(which i will buy in the morning) and charge each battery, hoping that they are not really "toasted".

And since i think i have answered all the questions asked, i will look for some more advice from you guys!

Thanks so far for the quick replies!!!

[mmichellich]

To charge 4 8-Ds from dead to full even with my 120 amp inverter charger would take all day. Yours may be good, just need completely charged.

[Guest]

mmichellich wrote:
To charge 4 8-Ds from dead to full even with my 120 amp inverter charger would take all day. Yours may be good, just need completely charged.

I do realize it will take all day or longer. getting my fat butt squeezed between the engine and the batteries will be even more challenging.

But how many amps will it show on my tester, that will tell me the battery is "too far gone" or "not chargeable"?

[mmichellich]

Sloppy2 wrote:
I do realize it will take all day or longer. getting my fat butt squeezed between the engine and the batteries will be even more challenging.

But how many amps will it show on my tester, that will tell me the battery is "too far gone" or "not chargeable"?

Charge them all up before testing any.

[Guest]

I isolated the first 2 batteries and charged them today.

First one was supprisingly at 12.4 so i charged it up to 13.4 on slow charge. I know it will stop and say "full" but i thought that was pretty good.

Wanted to get at least 2 of them charged today.

Second was at 12.2 and i charged it up to 13.3

Tomorrow i will charge the other 2 batteries and hopefully she will start up and they will keep their charge.

Then its time to get some shore power.

[Guest]

the rule of thumb that I remember from when I was setting up my system was that the charger output should approach 50% of the total amp hours of the battery bank.

You want to shove as much charge into the bank as fast as possible when re charging. Then taper, then float.

[Guest]

boatommy wrote:
the rule of thumb that I remember from when I was setting up my system was that the charger output should approach 50% of the total amp hours of the battery bank.

You want to shove as much charge into the bank as fast as possible when re charging. Then taper, then float.

Interesting. My buddy that gave me the charger said to do a slow charge. I wanted to do a 20 amp quick charge,

So your saying do a quick charge and then slow it down and taper it off?

[mmichellich]

Most all the 45 and 47s I have looked at do not use house batteries also as diesel start batteries. Most have a dedicated battery(s) for this purpose. What does the combine button do on your battery set up. Most boats use a combine button to parallel the engine start battery(s) to the house batteries when for some reason the engine start battery(s) has gone down too low to use. On our 47 I have one engine start 8-D, then four deep cycle 8-Ds for house/inverter batteries and a different 27 size gen start battery. Have never had to do any cross over to start since 1996. The 47 came new with two 8-Ds, one for house, and one for engine start which started both engines. If your 8-Ds are all deep cycle and you are using the deep cycle batteries also as starting batteries, you could have continued issues.

[Guest]

As a friend of mine used to say, "I know more about this than I understand."

You should probably do a google search through the xantrex site on batteries and charging, but yes, putting 20 amps, which is really probably only 15 or less after the charger heats up, into a battery bank your size is like peeing in an empty bathtub, or something like that

[Guest]

mmichellich wrote:
Most all the 45 and 47s I have looked at do not use house batteries also as diesel start batteries. Most have a dedicated battery(s) for this purpose. What does the combine button do on your battery set up. Most boats use a combine button to parallel the engine start battery(s) to the house batteries when for some reason the engine start battery(s) has gone down too low to use. On our 47 I have one engine start 8-D, then four deep cycle 8-Ds for house/inverter batteries and a different 27 size gen start battery. Have never had to do any cross over to start since 1996. The 47 came new with two 8-Ds, one for house, and one for engine start which started both engines. If your 8-Ds are all deep cycle and you are using the deep cycle batteries also as starting batteries, you could have continued issues.

Here is what I know now. My first 2 batteries are starting batteries and are not deep cell. The next 2 are house and are deep cell.

The combine button parallels the 2 start batteries to the 2 house batteries.

So today I finished charging the remaining 2 batteries(house). Everything is charged up and ready to start.

First, I try the starboard engines. She turns over quickly! Thank God!

Then I try the port engine. She starts to turn over and then click, click. No go.

I try the combine button and it doesnt help.

Since I cant hear the port engine very well when im trying to start her, with the starboard running, I decide to shut down the starboard

I try the port side again and just as I thought I heard before, a few turns and then clicks.

So I decide to start up the starboard engine again and watch the meter in the pilothouse to see, after running for a while, if it shows it is charging. Sometimes if I run the engine for

a while, the alternator will help charge the battery.

I try to start the starboard and nothing! not a click, nothing!

I just had it running and turning over fast 5 minutes ago!

So obviously this tells me my problem! Its not necessarily my batteries, but my connections.

So i guess tomorrow, I need to clean every connection! At the alternators, the combine button, the ground wires, everything i can find.

I know all the barrery connections are clean since i just spent the last 2 days doing that as i charged the batteries.

Thanks for all the help so far and lets see what tomorrow brings, unless anyone has any other suggestions for me.

Ed