Three 6 volt batteries and one 8 volt battery

[Tayana42]

Okay to start off I feel like a dummy for needing to ask this question. Four months ago I had my battery supplier install a new charger and house bank. The boat has been in a marina all that time on the charger on shore power. All seemingly good. Today I was checking and topping off electrolyte for the first time since the batteries were installed and much to my surprise I found I have three 6v batteries and one 8v battery!!! When they went in I did check to be sure the wiring pattern was correct but it didn't occur to me to verify that the batteries were all 6v.

Now my questions. They are all deka pro master batteries now four months old. Of course the 8 volt one has to be replaced. Should I insist that all four batteries be replaced? Would there be any damage to the charger, link lite monitor or other 12 volt appliances? What about using the boat as is while awaiting battery replacement?

Feeling somewhat foolish, thanks for your responses.

[rwidman]

OK, finish your post. How are these batteries wired together? Why is there one 8 volt battery? Was the 8 volt battery replaced with the others? Was there originally an 8 volt battery?

[Tayana42]

My house bank is supposed to be four 6v gc2 batteries wire series and parallel. The 8v battery was a mistake made by the battery supplier who also installed them. My mistake was not catching his mistake. So much for relying on professionals.

[gumme]

Mounting batteries in parallel, the lifespan of the batteries, depend to some extend on the capasety of the two batteries, and the charge status of the two batteries, when coupled up.

Have all 3 ''old'' batteries, and the new, capacety tested, and make sure the new 6 volt is charged fully paralelt with the old one it have to work togeter with. Merge the batteries so the have as close as posible capasety in each serial line.

Just to uptomise performance, and lifetime.

Did that give any meaning ? ;-)

Henrik

[rwidman]

Originally Posted by Tayana42

My house bank is supposed to be four 6v gc2 batteries wire series and parallel. The 8v battery was a mistake made by the battery supplier who also installed them. My mistake was not catching his mistake. So much for relying on professionals.

Well, the professional should replace the 8 volt battery with a six volt battery at no charge.

It seems odd that someone would or could make that mistake. 8 volt batteries are pretty rare.

I can't think of a reason anything else would have been damaged. Depending on how the 8 volt battery failed, you may be running on just one pair of batteries.

[Tayana42]

The 8v hasn't failed. Neither have the 6v batteries. Yes it is odd that they made this mistake. I'm sure the supplier will replace the wrong battery. Should I insist he replace all four batteries?

[Sailmonkey]

Originally Posted by Tayana42

The 8v hasn't failed. Neither have the 6v batteries. Yes it is odd that they made this mistake. I'm sure the supplier will replace the wrong battery. Should I insist he replace all four batteries?

I don't think you'll need that. The 8 volt battery has most likely been dragged down to the level of the 6 volt cells and is toast, however sitting on shore power the other batteries at 4 months old are essentially new.

[rwidman]

Originally Posted by Tayana42

The 8v hasn't failed. Neither have the 6v batteries. Yes it is odd that they made this mistake. I'm sure the supplier will replace the wrong battery. Should I insist he replace all four batteries?

But you posted that it had to be replaced. ???

You can insist anything you want but you can't force him to replace the other batteries. I doubt it's worth going to court over.

[transmitterdan]

Is this a 12V boat or a 24V boat?

If it's 12V boat then the 6V and 8V in series are both getting less than full charge. Replace the 8V with a 6V and get the technician to balance charge all four 6V batteries in parallel. Then reconnect them in series parallel as before.

A good technician will have access to a 6V charger.

[Cadence]

I doubt it has caused any damage if short term. The supplier I feel short will make it good by giving you a new 6V. Good business sense would be rebating you the cost of one battery.

[wcapman]

Just my 2 cents from almost 50 years of batteries and boats. If an 8v was installed with a 6v and paralleled with 2 other 6v batteries, I would insist that they take them all back and replace with a fresh set. When you have 2 6 volt batteries, they should be of the same manufacture and the same date code. Think of it this was. In a 12v batter all four cells SHOULD have the same chemistry, or close to it. Each cell will accept a charge more or less equally giving maximum battery life. 6v batteries in series are just like a 12v. The chemistry of each cell must be closely matched or one battery will suck up more charging current than the other resulting in early sulfation of the weaker charged battery. After a year or two you will have battery failure. Conversely if you connect 2 12v batteries in parallel (or 2 6v series parallel banks) all four batteries should me matched for mfgr and date codes. Once you are off teh charger, the good battery bank will drain into the weaker battery bank and discharge itself. Paralleling 12v banks is good for starting a heavy load, like a engine or windlass, but alternating between banks during normal non-charging load conditions will result in the best overall capacity.

Always replace 6vGC batteries in pairs.
Always check the date codes and insist they be the same. Some suppliers will try to push older batteries first and you couild end up with 1 older battery in a bank of 4.

Always use nothing but distilled water to top off a battery.
Always check the cell electrolye with a hydrometer before adding water. It will help detect a weak cell before there is a problem.
Watch for one cell needing more water than the others. That indicates a weak cell that is sucking up the charge current.

Hope that helps.

[mitiempo]

Originally Posted by transmitterdan

Is this a 12V boat or a 24V boat?

If it's 12V boat then the 6V and 8V in series are both getting less than full charge. Replace the 8V with a 6V and get the technician to balance charge all four 6V batteries in parallel. Then reconnect them in series parallel as before.

A good technician will have access to a 6V charger.

I agree but any professional that confuses a 6 volt battery with an 8 volt battery isn't very smart or professional. I would find someone else qualified to do this.

[Cadence]

Originally Posted by mitiempo

I agree but any professional that confuses a 6 volt battery with an 8 volt battery isn't very smart or professional. I would find someone else qualified to do this.

A 6V and an 8V don't look that different.
The guy in the warehouse is probably just a kid or someone not to bright hired to do the grunt work.
Long story short. My brother an I had to go to the funeral parlor to ID Mom it wasn't her they showed us laid out. $hit happens. I'm sure the guy pulling them out of the reefer was no brain child. Maybe smarter than the guy pulling batteries.

[mitiempo]

Originally Posted by Cadence

A 6V and an 8V don't look that different.
The guy in the warehouse is probably just a kid or someone not to bright hired to do the grunt work.
Long story short. My brother an I had to go to the funeral parlor to ID Mom it wasn't her they showed us laid out. $hit happens. I'm sure the guy pulling them out of the reefer was no brain child. Maybe smarter than the guy pulling batteries.

But how smart was the installer?

[Cadence]

Originally Posted by mitiempo

But how smart was the installer?

That's a good question? And who installed them?