Blige pump problem!

[Sweden123]

Hello me and my brother have an issue with the bilge pump , it drains the battery very quick and last year 4 batteries got destroyed. This year we bought an switch panel from Amazon and a solar panel with a regulator but we see no changes.
Right now we have a smaller 12V battery 7.2 Ah and the bilge pump consume 3A.
It takes about one week and the battery needs to charge agian.
We hope someone here at iboats with better experience can help us!
Have a good day / Sweden123

 

[mike_i]

Why is the pump running so much that it runs the battery down?

 

[dingbat]

What make and model is the bilge pump?
Output of your solar charger?

Could be a couple of things:
Is the pump by chance auto-sensing?
Supply (charger) not meeting demand (pump)?

Lead acid batteries don't live long if DOD is greater than 50% (~12 volts)

Electric motors will often "leak" current to ground before failing outright.
Need to put a meter on the positive wire running to the bilge pump to see if your "leaking" current to ground

 

[Sweden123]

Why is the pump running so much that it runs the battery down?

The bilge pump have a level guard and its not raining that much. We tested the bilge pump yesterday and it started and 0.2V gone from the battery after a quick test.

 

[Sweden123]

What make and model is the bilge pump?
Output of your solar charger?

Could be a couple of things:
Is the pump by chance auto-sensing?
Supply (charger) not meeting demand (pump)?

Lead acid batteries don't live long if DOD is greater than 50% (~12 volts)

Electric motors will often "leak" current to ground before failing outright.
Need to put a meter on the positive wire running to the bilge pump to see if your "leaking" current to ground

The bilge pump is from a local store here in Sweden called Biltema which means car theme and the pump have no name at all.
The bilge pump is a 16.6 gallons per minute and consume 3A and using auto sensing.
Here is the solarpanel kit from Amazon Puooifrty 180W Solar Panel Kit 12V Battery Charger with 100A Control for Boat RV
When the pump starts the volt drop 0.2V...
Thanks for all the good information , we have a multimeter we can use but we dont know how it works. The multimeter is from car theme haha
I will upload pictures on thursday.

 

[airshot]

Why not stop the water going into the boat, seems that might be a better solution !!

 

[dingbat]

The bilge pump is a 16.6 gallons per minute and consume 3A and using auto sensing.

3A = 38 Watts per minute of run time
12V, 7.2 AH = 92 watts of battery capacity
Battery provides 2.4 minutes of run time

Auto sensing runs the pump for X duration, every X minutes.
How much current is used per cycle and how often is the pump "sensing?

Here is the solarpanel kit from Amazon Puooifrty 180W Solar Panel Kit 12V Battery Charger with 100A Control for Boat RV

Your battery is way undersized for the task.
Your solar panel is capable of outputting 180 W, but your battery only has the capacity to store 92 watts. Leaving a lot on the table running at 51% capacity

 

[Sweden123]

Why not stop the water going into the boat, seems that might be a better solution !!

May be an solution but we prefer to use a bilge pump

 

[Sweden123]

3A = 38 Watts per minute of run time
12V, 7.2 AH = 92 watts of battery capacity
Battery provides 2.4 minutes of run time

Auto sensing runs the pump for X duration, every X minutes.
How much current is used per cycle and how often is the pump "sensing?


Your battery is way undersized for the task.
Your solar panel is capable of outputting 180 W, but your battery only has the capacity to store 92 watts. Leaving a lot on the table running at 51% capacity

Very interesting , how do you calculate this?
12V x 7,2 Ah = 86,4 watts of battery capacity.
The bilge pump only runs when it detects water and last time we tested the bilge pump 0,2 V just disappeared from the battery.
We had bigger batteries last year but they got destroyed and we have no idea why either.
My brother think the bilge pump destroy all the batteries...
But i agree with you , the battery we use now are way to small for this purpose.
Thanks for replying / Sweden123

 

[dingbat]

Very interesting , how do you calculate this?
12V x 7,2 Ah = 86,4 watts of battery capacity.

Volts x Amps = Watts
12 x 7.2 = 86.4 Watts

The bilge pump only runs when it detects water

Are you sure about that?
Most "auto-sensing" pumps cycle a small detection circuit every so often. Rule pumps cycle (1.2 mA) every 2.5 minutes looking for the presence of water.

We had bigger batteries last year but they got destroyed and we have no idea why either.

My brother think the bilge pump destroy all the batteries...

And we would be correct.

Conventional flooded acid batteries are not designed to be discharged more than 50% (in your case, 43 W) of their rated capacity. Doing so has a deterimental effect on battery life. Do it more than a couple of time and you've killed the battery.

You really need to use a deep cycle battery in this application.

 

[airshot]

Volts x Amps = Watts
12 x 7.2 = 86.4 Watts

Are you sure about that?
Most "auto-sensing" pumps cycle a small detection circuit every so often. Rule pumps cycle (1.2 mA) every 2.5 minutes looking for the presence of water.

And we would be correct.

Conventional flooded acid batteries are not designed to be discharged more than 50% (in your case, 43 W) of their rated capacity. Doing so has a deterimental effect on battery life. Do it more than a couple of time and you've killed the battery.

You really need to use a deep cycle battery in this application.

According to Johnson Controls battery engineer, the 50% is for a deep cycle, regular flooded cell batteries
( starting type) should not be drawn down below 75% capacity for longest life. A regular starting battery will be killed after drawing down to 50% a couple times. Hope this is an aluminum boat, a glass boat with that much water is certain to cause stringer rot over time.

 

[tpenfield]

If it is one of those auto-sensing bilge pumps? Throw it away and get a regular float activated pump.

BTDT . . . wasted a battery in about 1 week.

 

[JASinIL2006]

If it is one of those auto-sensing bilge pumps? Throw it away and get a regular float activated pump.

BTDT . . . wasted a battery in about 1 week.

I agree. Those auto-sensing pumps just drain betteries.

 

[dingbat]

According to Johnson Controls battery engineer, the 50% is for a deep cycle, regular flooded cell batteries
( starting type) should not be drawn down below 75% capacity for longest life.

A good argument for not using an “automotive” starting battery on a boat. A Marine starting (dual purpose) battery is a much better choice.

FWIW: He is using a solar rated battery. I use the same battery in my solar powered electric fence installations. Get about 2 years out of a battery running 24/7/365.

 

[Sweden123]

Volts x Amps = Watts
12 x 7.2 = 86.4 Watts

Are you sure about that?
Most "auto-sensing" pumps cycle a small detection circuit every so often. Rule pumps cycle (1.2 mA) every 2.5 minutes looking for the presence of water.

And we would be correct.

Conventional flooded acid batteries are not designed to be discharged more than 50% (in your case, 43 W) of their rated capacity. Doing so has a deterimental effect on battery life. Do it more than a couple of time and you've killed the battery.

You really need to use a deep cycle battery in this application.

Ah okay , yes im pretty sure , it only runs when it detects water and then it shutdown but sometimes it takes a while for it to shutdown.
Really big thanks for your replies dingbat it make me think alot and i will go to the store and buy a new battery very soon!

 

[Sweden123]

If it is one of those auto-sensing bilge pumps? Throw it away and get a regular float activated pump.

BTDT . . . wasted a battery in about 1 week.

Its a bilge pump with built-in level guard
But i need to buy a new battery very soon 7,2 Ah is not much to play with haha

 

[Sweden123]

What kind of battery do you recommend for me?
I see there are many batteries on the market.
SFI , EFI and AGM. I think AGM would be a good choice. We are going to use the battery for our bilge pump and some navi lights.
Is it safe to use the solar kit from Amazon with the new battery?
/Sweden123

 

[mike_i]

Seems like the most logical common sense first thing to do but your suggestion just got blown off, wow.

Why not stop the water going into the boat, seems that might be a better solution !!

 

[airshot]

Seems like the most logical common sense first thing to do but your suggestion just got blown off, wow.

To each his own....we can only suggest...

 

[saaristo]

I like my boats bikges bone-dry. I do not get the boat owners whos 25...26 ft bayliners and searays etc etc are shooting out a bucket of water every 10 minutes or so. But you see that a lot if you pay attention. Other than that, these autosensing pumps are known to drain whatever the size of the battery.