Are these deep cycle batteries? Why can't I check the electrolyte levels?

[goboatingnow]

Originally Posted by Emmalina

Not a big fan of chargers with fans LOL yep not good ups batteries as house bank

Almost all modern chargers have speed controlled fans , my victron has a “ night mode “ where it reduces charge current and hence fan speed so as not to disturb sensitive sleepers like u.

[Whiteoil]

Yeah I was considering flood lead acid batteries and top them up every so often. I'm not sure, could the bow thruster operate off 3 deep cycle batteries? Would the current battery charger be sufficient?

I have not even confirmed my current batteries are bad, right now I only know the battery charger is louder... i'm watching the 12 part series by Pacific yachting on marine electrics so that's helping.

Originally Posted by SteveSails

If the charger has a speed controlled cooling fan it will run faster as the charger heats up under load and make considerable noise. If your loads have increased recently that could explain the increased noise. Victron has a night mode on their chargers, the charger runs at reduced power so the fan doesn't keep you up all night. If the noise more like a hum or a vibration then there could be a fault in the charger. In any case I would replace the batteries. What kind of batteries? Flooded lead acid, AGM or even Lithium? That's whole other topic.
BTW, I recommend you don't get lithium until you have a better understanding of batteries and charging systems.

[Whiteoil]

Originally Posted by Sailmonkey

When your charger is making noise, what is the battery voltage?

I’ve a hunch that the charger has cooked the batteries by staying at absorption voltage anytime there is a load on the batteries while they’re being charged.

How could I confirm the batteries are cooked?

[Sailmonkey]

Originally Posted by Whiteoil

How could I confirm the batteries are cooked?

Quick, non-scientific way is to turn off the charger and see how long the batteries will run your boat before the voltage collapses.

[GordMay]

Originally Posted by Whiteoil

How could I confirm the batteries are cooked?

Insert a wooden toothpick, near the center of the battery. If the toothpick comes out clean, the battery is cooked.

[Chuck34]

Originally Posted by Whiteoil

How could I confirm the batteries are cooked?

Cooked or not…they were not designed to be used on a boat and need to be replaced.

[landsend]

Sailmonkey:



Quick, non-scientific way is to turn off the charger and see how long the batteries will run your boat before the voltage collapses.



Absolutely correct!! Just changed out my AGM batteries. By mistake I turned off the charger, 4 seconds later no power.

[Lake-Effect]

Originally Posted by Chuck34

Cooked or not…they were not designed to be used on a boat and need to be replaced.

Very few batteries were designed to be used on a boat.

Yes the choice of UPS batteries is not optimum... maybe they were real cheap or free to the PO. Maybe the PO just made short trips and they were adequate.

The only reliable ways to know whether any house batteries are useable (capacity or condition) are:

• haul them to a battery vendor's and get them tested with a decent battery analyser (results taken with a grain of salt) -or-
• do a load test. Here are the steps for a "C/20" test. In a nutshell, you find your battery's true Ah (Amp/hour) capacity by charging it fully, then pulling X Amps (where X is the rated Ah divided by 20) until the battery voltage reaches 10.5v (do not go lower), then multiply X by the number of hours the test ran, and that's your real battery capacity.

Only the OP can decide what capacity in Ah would be adequate for their intended use. There are other considerations too: UPS type batteries are generally just trickle-charged constantly, so they might not respond well to deep discharge followed by rapid charging. The battery's specs don't provide a recommended charging profile or current.

[Whiteoil]

I left the charger off and it runs the fridge for 4 hours with a 20 percent discharge . So they still operate. I'm just unsure why the battery charger is humming away like it's the end of the world now and then.

I am living on the boat right now, but ideally the batteries would run my fridge and autopilot for 12-18 hour hops.

The three AGM UPS batteries are below the forward berth bunk, where I'm currently sleeping (until I've replaced my exhaust elbow- coming tomorrow, then i'll sleep in the aft again). Also picking up my new foams cushions. The batteries aren't going to blow up on me right? I've removed one to check the label and put it back and redid the "hack" wiring job. I don't need to worry about sleeping on top of them for a couple more days without blowing a hole through the middle of myself? Right? They're not overly hot or anything.

Originally Posted by Lake-Effect

Very few batteries were designed to be used on a boat.

Yes the choice of UPS batteries is not optimum... maybe they were real cheap or free to the PO. Maybe the PO just made short trips and they were adequate.

The only reliable ways to know whether any house batteries are useable (capacity or condition) are:

• haul them to a battery vendor's and get them tested with a decent battery analyser (results taken with a grain of salt) -or-
• do a load test. Here are the steps for a "C/20" test. In a nutshell, you find your battery's true Ah (Amp/hour) capacity by charging it fully, then pulling X Amps (where X is the rated Ah divided by 20) until the battery voltage reaches 10.5v (do not go lower), then multiply X by the number of hours the test ran, and that's your real battery capacity.

Only the OP can decide what capacity in Ah would be adequate for their intended use. There are other considerations too: UPS type batteries are generally just trickle-charged constantly, so they might not respond well to deep discharge followed by rapid charging. The battery's specs don't provide a recommended charging profile or current.

[Sailmonkey]

Originally Posted by Whiteoil

I left the charger off and it runs the fridge for 4 hours with a 20 percent discharge . So they still operate. I'm just unsure why the battery charger is humming away like it's the end of the world now and then.



I am living on the boat right now, but ideally the batteries would run my fridge and autopilot for 12-18 hour hops.



The three AGM UPS batteries are below the forward berth bunk, where I'm currently sleeping (until I've replaced my exhaust elbow- coming tomorrow, then i'll sleep in the aft again). Also picking up my new foams cushions. The batteries aren't going to blow up on me right? I've removed one to check the label and put it back and redid the "hack" wiring job. I don't need to worry about sleeping on top of them for a couple more days without blowing a hole through the middle of myself? Right? They're not overly hot or anything.

What is the voltage at the end of the 4 hour interval. 20% discharge is sort of a squishy number depending on how your ah counter is configured.

[Lake-Effect]

Originally Posted by Sailmonkey

What is the voltage at the end of the 4 hour interval. 20% discharge is sort of a squishy number depending on how your ah counter is configured.

yes this ^ ^ ^

That's why a discharge test is most accurate when it's between two defined points: full charge, and exhausted (10.5v).

And, OP when you complain of charger noise, is it the fan, or what? If it's the fan, they're usually on some sort of internal thermostat that switches it to full at an arbitrary temperature, which is only loosely correlated with charge current.

[StuM]

Originally Posted by Whiteoil

So they still operate. I'm just unsure why the battery charger is humming away like it's the end of the world now and then.

Bearing in the cooling fan wearing out?

[BayouSailing]

Sufficient questions have been raised, by Original Poster (OP), related to configuration done by Previous Owner (PO); that we can develop a clear understanding that OP is on a fast track of electrical education but starting at a remedial level.
OP, you can get there.
The path is steep, but not that hard.
But you need to start with a full electrical analysis of your vessel, storage, loads, charge sources; and then balance that equation.
I recommend you check yet another website, www.abycinc.org , and find a certified marine electrician in your area to walk you through this.
It can be done remotely, by myself or others, but you're really going to want someone on board with you as you change out critical components the first time.
This is not an emergency, but it is not an internet job. Doing it based upon the multitude of advice you may get off the internet may create an emergency, i.e. a fire, WHICH BY THE LAWS OF NATURE WILL SELF EXTINGUISH, when it reaches the water line.

[Joe Okros]

Those batteries are fine for a bow thruster's occasional use. I would keep them for that purpose and it's probably the reason they are located where they are. You need a dedicated "house battery" for lighting, fridges etc and a separate dedicated "starter battery" for your engine. With all that you will need to figure out a way to connect them all to charging sources and a way to combine or isolate them. Then of course, if you need to pull up an anchor you need to take care of that as well. LOL.--fun times in your future

[goboatingnow]

Originally Posted by BayouSailing

Sufficient questions have been raised, by Original Poster (OP), related to configuration done by Previous Owner (PO); that we can develop a clear understanding that OP is on a fast track of electrical education but starting at a remedial level.
OP, you can get there.
The path is steep, but not that hard.
But you need to start with a full electrical analysis of your vessel, storage, loads, charge sources; and then balance that equation.
I recommend you check yet another website, www.abycinc.org , and find a certified marine electrician in your area to walk you through this.
It can be done remotely, by myself or others, but you're really going to want someone on board with you as you change out critical components the first time.
This is not an emergency, but it is not an internet job. Doing it based upon the multitude of advice you may get off the internet may create an emergency, i.e. a fire, WHICH BY THE LAWS OF NATURE WILL SELF EXTINGUISH, when it reaches the water line.

Funny so called professionals threatening fire and brimstone , boring

Ps Ive done more battery technology in my career then so called marine electricians have had hot dinners , most of whom can hardly understand a multimeter,

The OP has a louder fan on his charger , the world is not coming to an end.