batteries boil over when using dual battery charger/maintainer

[Frisky Business]

Have a Nautilus dual battery charger/maintainer but both batteries boiled dry twice during the winter in the basement and then once when installed on the boat during this past summer. What good is a maintainer if you have to babysit it? Anybody every seen this before? Any suggestions as to what to do?

 

[Peter Eikenberry]

Re: batteries boil over when using dual battery charger/maintainer

simple answer, it's being overcharged. Why? Something wrong with the charger/maintainer. It's not regulating the voltage correctly. It sounds like it is never getting out of the bulk charging stage. You need to have the charger checked out.

 

[Auger01]

Re: batteries boil over when using dual battery charger/maintainer

Toss the charger in the garbage. It is toast.

12v Battery Charger, Battery Desulfator, Battery Maintainer, Charger

 

[sam am I]

Re: batteries boil over when using dual battery charger/maintainer

I picked up two of these at O'Riellys for $29.99 ea.

Schumacher Onboard Battery Maintainer ? 12 Volt, 1.5 Amp, Model# SE-1-125 | Battery Maintainers| Northern Tool + Equipment

Seemed to be doing okay for the price, can even mount them in your boat.

 

[gm280]

Re: batteries boil over when using dual battery charger/maintainer

Most battery charger/maintainers have a circuit that monitors the peak over charge condition on the battery and then shuts down to a trickle charge for the maintaining portion of the cycle. But is sounds like your charger/maintainer circuit isn't sensing that peak over charge event and continues charging until all the electrolyte solution is evaporated...bad, very bad! The battery charges until the peak voltage breaks over the peak charge. It then drops a little and that triggers the peak over event meaning the battery is 100% charged. So it sounds like your charger is not functioning properly. If you have a warrantee with it yet you may can get it replaced....

 

[UncleWillie]

Re: batteries boil over when using dual battery charger/maintainer

Understanding the basics of battery charging may help.

A typical Flooded Lead Acid Battery will have a resting voltage of ~12.6 volts.
Most any battery will be charged if it connected to a voltage of more than ~13.8v. 14.5v is a typical voltage but it can often be found anywhere between 14 and 16 volts.

Every battery has a "Float" Voltage somewhere near 13.5v, where it can be held at indefinitely, and it will remain 100% charged without Boiling off the water. Maintaining this voltage is problematic because it varies with the exact chemistry of the battery and the temperature of the cells. A few degrees of temperature change would require the voltage to be adjust slightly. A correction of 0.002v per degree F is typical. With out knowing the chemistry of the battery and having a temperature probe attached to the case of the battery, Maintaining the correct Float Voltage would be impossible.

To overcome this issue, "Maintainer" Type Chargers typically charge the battery into the lower 14 volt range and then shut OFF.
When the charger detects that the battery voltage has dropped to near 13.0 volts, The charger turns back ON at a 2-3 Amp Charge rate.
When the voltage reaches 14+ volts again, the Charger shuts OFF again, and the cycle repeats.

If you place a meter on the battery, you will see the voltage slowly drop to near 13v and then very quickly jump up to 14+.
This will typically give the battery a 1 second charge about once every 2 minutes. This totals to about 10 minutes of charging per day.
It also produces an average long term voltage that equals that Magic Float voltage.

 

[bruceb58]

Re: batteries boil over when using dual battery charger/maintainer

If your battery had one bad cell, it would also boil out the cells of the good cells although the chance of two having this issue is not likely.

 

[JoLin]

Re: batteries boil over when using dual battery charger/maintainer

I picked up two of these at O'Riellys for $29.99 ea.

Schumacher Onboard Battery Maintainer — 12 Volt, 1.5 Amp, Model# SE-1-125 | Battery Maintainers| Northern Tool + Equipment

Seemed to be doing okay for the price, can even mount them in your boat.

The term 'onboard' here does NOT refer to it being an 'inherently safe' (spark-protected), marine rated charger. IMO, these should not be mounted permanently on a boat.

 

[Thalasso]

Re: batteries boil over when using dual battery charger/maintainer

The term 'onboard' here does NOT refer to it being an 'inherently safe' (spark-protected), marine rated charger. IMO, these should not be mounted permanently on a boat.

They shouldn't be mounted at all. They can cause DC leakage into the water if hooked to shore power and cause electrolysis.

 

[bruceb58]

Re: batteries boil over when using dual battery charger/maintainer

They shouldn't be mounted at all. They can cause DC leakage into the water if hooked to shore power and cause electrolysis.

I would think if they have a plastic case, they should be fine. Even if the case was metal, they would have to be mounted to an aluminum boat or the engine for it to matter.

All bets are off with those Schumacher chargers though. I would never use those for a few reasons.

I picked up two of these at O'Riellys for $29.99 ea.

By the way, Amazon has them for $22.

 

[sam am I]

Re: batteries boil over when using dual battery charger/maintainer

The term 'onboard' here does NOT refer to it being an 'inherently safe' (spark-protected), marine rated charger. IMO, these should not be mounted permanently on a boat.

You certainly could be right, I didn't read the destruction manual before I flippantly said that but, I did go fetch it and it says.....

"Use the battery charger on 6 and 12V LEAD-ACID, GEL and AGM-type rechargeable batteries with recommended rated capacities of 12 Ah (6V) and 5-33Ah (12V), as used in automobiles, trucks, tractors, airplanes, vans, RV's, trolling motors, etc." :noidea:

It never states though, I read the entire thing, "inherently safe (spark-protected), marine rated charger", you are correct.

http://www.amazon.com/Schumacher-SE...p/B0000AXTUY/ref=pd_sbs_auto_5#productDetails

"Product Description
This fully automatic onboard battery charger is a 1.5-amp charger which plugs onto an electrical wall outlet. This unit charges 12-volt batteries, and keeps larger batteries warm even under cold temperatures. This plug-in trickle charger has reverse polarity protection and can install next to the battery on automobiles, boats, tractors, golf carts, and other equipment. Appropriate hardware and mounting brackets are included with this battery charger."

 

[sam am I]

Re: batteries boil over when using dual battery charger/maintainer

By the way, Amazon has them for $22.

Doh......Oh well, I was in a hurry to have looked online, I didn't even know I wanted them, just saw them on the shelf and bought them. They seem to be working okay so far, no boiling and maintain function is working fine.

I don't think I will be leaving them plugged in anyway though for more than maybe 2 days a month through/over winter. Other then that, I don't use chargers/maintainers during summer, I'm out almost daily seems sometimes.

 

[bruceb58]

Re: batteries boil over when using dual battery charger/maintainer

I bought one of the chargers that I have on eBay for 80$. It is a dual bank 3 stage 5 amps per bank and its a marine charger. I would suggest that over 2 of those Shumachers.

 

[JoLin]

Re: batteries boil over when using dual battery charger/maintainer

Doh......Oh well, I was in a hurry to have looked online, I didn't even know I wanted them, just saw them on the shelf and bought them. They seem to be working okay so far, no boiling and maintain function is working fine.

I'm just advising you to be cautious. I use a portable smart charger on my boat a couple times a year to desulfate the batteries. I do it this way...

1. Open the engine hatch and do a sniff test.
2. Position the charger in the cockpit, above deck, and run the leads to the battery down in the ER.
3. Attach the leads to the battery.
4. Plug in the charger.
5. When done, unplug the charger, THEN detach the battery leads.

If it sparks at the 115V connection when I connect/disconnect it, it won't blow anything up.

 

[sam am I]

Re: batteries boil over when using dual battery charger/maintainer

Good advice, thank you......I did notice it has a "auto-start feature, to not supply current to rings/clamps until properly connected" but, certainly should not second guess "smart" features such as that, best to follow a procedure such as yours always!!

I have the batts out of the boat in the garage for the winter......