Boiled Battery - Who's to Blame?

[gbendaly]

hello all

having boiled my domestic use battery lately , I hesitate to install the expensive newly purchased 105 Ah marine one in the bank before making sure it won't face the same fate I must point out that my knowledge in electrical matters is limited and the boat was purchased supposedely professionally wired up.

the charging in is done by means of :

1. one 75 watt solar panel , (connected via a battery isolator)
2. the engine alternator connected to the rotary switch and to the isolator
3. a sterling 30 A 4 stage charger ( god knows how it is connected)

I am wondering if any one in this forum will be kind enough to enlighten me whether the fault goes to the old fried battery (which was two years old) or to one of the fore -mentioned items
I would very much appreciate any feed back on the matter and any wiring or diagram of connection suggested to make sure this won't happen again
thank you.
in order not to overload this forum by further explanations or sketches you might want to send me you can E-mail me on
gbendaly@gmail.com

[markpj23]

I would not think a maintained 2-year old battery would be the cause of anything. Is it the only one in the bank? Need some more details on your system else we're all just stabbing in the dark....

[camaraderie]

Does the solar panel have its' own regulator or is it hooked up directly to the isolator?
Did you religiously keep the water topped up with DISTILLED water over the two years and NEVER let the plates become exposed?

[chris_gee]

I wonder if it is possible that the solar panel is pushing out say say 6 amps and you need only a tiny float charge of say .5 amp after the main charging. If it is not going through the smart charger this could overcharge and burn out the battery. I also had the idea that excess amperage from the solar panel had to go somewhere eg to refrigeration or lighting or fans. Normally a 10 watt solar panel would provide ample for a battery top up and that size could well power a small refrigerator or close to. However my understanding of these things is limited.

[gbendaly]

the solar panel is directly hooked up to the isolator
and the batteries are the sealed type maintenance free

[gbendaly]

two batteries one 75 Ah for the engine and another 105 Ah for domestic use , both are the sealed type marine deep cycle maintenance free and being charges either by the engine alternator when motoring,or by trhe 4 stage sterling charger when tied to the pontoon but always withe 75 watts solar panel which is connected to the negative pole on one battery and to one end of the isolator, I would have sent some pictures I took from the charger but I cannot find the attachment clip

[gbendaly]

maybe it can be of some help

[jdoe71]

Your Sterling charger looks exactly like my ProMariner ProTech4 30 amp charger, right down to the decals. Mine is black. They sure look the same though I have no idea if Sterling makes for ProMariner or vice versa but it's either the same unit or a knock off of one.

I have never had a problem with it doing anything weird with the batteries, it functions exactly as it should according to my Microlog monitoring system. But without putting voltage/amperage metering on it, you'll never know. It could be defective and is not going into float properly.

Do you have the Gel/flooded switches set correctly on it? It is under the cover on the end of the charger were the wires come out. When you say your batteries are sealed, are they Gel, AGM or just sealed flooded lead acid? Makes a big difference.

[camaraderie]

A 75 watt panel will generally put out 17.5 volts in full sunshine and fry ANY battery. You need a regulator for the panel...that is what killed them.

[David M]

Don't guess. Fixing something that isn't broken gets expensive.

It could be any of your DC sources which means your solar charger, your battery charger or your alternator that is causing the over voltage.

Disconnect two out of three of your DC sources. Turn on the remaining DC source and put a good digital multimeter across your DC system where your battery got destroyed. Do this with a new battery in its place. Watch the voltage when your DC source is charging. It should never get much over 14 volts. Test your other DC sources in the same way, by turning off or disconnecting all but one DC source.

This way you can nail down which is the problem child without guessing.

Once you have determined which DC source is the problem, you may need to replace the regulator for that source. Before you replace the regulator, make sure all your electrical connections are clean and tight, especially any voltage sensor wires.

[CharlieJ]

I agree with Cam above...the unregulated solar panel is the culprit. High voltage is what kills batteries during the charge cycle.

By the way, most batteries do not die a natural death; they are murdered!!

[Evan]

Ditto the solar panel. It needs some sort of regulator unless you are running an amp.hour deficit. Consider this scenario. You motor for 5 hours, fully charging the battery with the alternator. Then you turn off the engine. The sun is still up, and the solar power is putting power into a fully charged battery. Of course you cook it!

[gbendaly]

thanks guys for all your inputs and feedback I wll order a regulator for the solar panel and will test individually all the DC sources as suggested
to be sure all the DC sources are OK

[gbendaly]

Originally Posted by jdoe71

Your Sterling charger looks exactly like my ProMariner ProTech4 30 amp charger, right down to the decals. Mine is black. They sure look the same though I have no idea if Sterling makes for ProMariner or vice versa but it's either the same unit or a knock off of one.

I have never had a problem with it doing anything weird with the batteries, it functions exactly as it should according to my Microlog monitoring system. But without putting voltage/amperage metering on it, you'll never know. It could be defective and is not going into float properly.

Do you have the Gel/flooded switches set correctly on it? It is under the cover on the end of the charger were the wires come out. When you say your batteries are sealed, are they Gel, AGM or just sealed flooded lead acid? Makes a big difference.

the engine battery is gel while the newly purchased domestic one is an AC DELCO marine lead calcium deep cycle sealed battery
and I will have a look at the switches as you kindly suggested I will have to unscrew the cover on the far right side for that, is the setting of these switches the same for the gel and calcium lead batteries ??thanls Jdoe

[camaraderie]

No...you can't max the two types and charge with the same source. Get a new engine battery or charge it separately.