Barry Oliver

Most sounders have a voltmeter which will tell you battery voltage. Mind you, not much good if your electric motor is on a different circuit. 🙂
This is the voltages discharges:
% of Charge (discharged DOD)             Volts
100              0                               12.7
90                10                             12.58
80                20                             12.46
75                 25                           12.40
70                 30                         12.36
65                 35                         12.32
60                  40                       12.28
50                   50                       12.20
Discharged   >50                     11.90
My minn has a battery level indicator. I found this:
"For my motor, four is 12.8v or better, three lights is 12.6v two, 12.5, and one light is 12.3v. "
If true, then the lowest light indicates about 60-65% of charge, which makes sense.
As ellicat implies- easy enough to get an inline voltmeter - Jcar or something similar sell them.
Raises a question of how long your deep cycle battery would last if discharged regularly...probably depends upon the type and quality of battery and how long it was left discharged.
How long is a piece of string?
However a mate of mine had a deep cycle last 10yrs from carefully managing it. I also read a marine battery has an expected life of 1-6yrs. I expect if you discharge to more than 50% regularly its going to be 1yr, and 6yrs if you don't go below 80% or thereabouts and recharge soon after discharge.
I found this:
"Battery life is directly related to how deep the battery is cycled each time. If a battery is discharged to 50% every day, it will last about twice as long as if it is cycled to 80% DOD. If cycled only 10% DOD, it will last about 5 times as long as one cycled to 50%. Obviously, there are some practical limitations on this - you don't usually want to have a 5 ton pile of batteries sitting there just to reduce the DOD. The most practical number to use is 50% DOD on a regular basis. This does NOT mean you cannot go to 80% once in a while. It's just that when designing a system when you have some idea of the loads, you should figure on an average DOD of around 50% for the best storage vs cost factor. Also, there is an upper limit - a battery that is continually cycled 5% or less will usually not last as long as one cycled down 10%. This happens because at very shallow cycles, the Lead Dioxide tends to build up in clumps on the the positive plates rather in an even film. The graph above shows how lifespan is affected by depth of discharge. The chart is for a Concorde Lifeline battery, but all lead-acid batteries will be similar in the shape of the curve, although the number of cycles will vary."
 
Cheers
B

Hi guys,
Thanks for all the thoughts, although I suggested the 'missus' issue to her and I'm now writing this from my hospital bed...;-)....I don't think that was so helpful...:-)
I did the testing both up and down the river in very calm conditions to exclude water/environment.
The motor is a new 60hp Yamaha. It does have a sacrificial trim tab which is offset to the RHS about 8 degrees- this is the recommended setting afaik. Also afaik the trim tab impacts the steering rather than any list/heel.
I undid the bungs after the test and there was no water in hulls.
I've heard back from Brisbane Yamaha and they want the boat back to do their own tests- bring on the unlockdown....given the boat is new not much I want to fiddle with. Anyway will let you all know one day...

Hi guys,
Thanks for all the thoughts, although I suggested the 'missus' issue to her and I'm now writing this from my hospital bed...;-)....I don't think that was so helpful...:-)
I did the testing both up and down the river in very calm conditions to exclude water/environment.
The motor is a new 60hp Yamaha. It does have a sacrificial trim tab which is offset to the RHS about 8 degrees- this is the recommended setting afaik. Also afaik the trim tab impacts the steering rather than any list/heel.
I undid the bungs after the test and there was no water in hulls.
I've heard back from Brisbane Yamaha and they want the boat back to do their own tests- bring on the unlockdown....given the boat is new not much I want to fiddle with. Anyway will let you all know one day...

Hi guys,
Thanks for all the thoughts, although I suggested the 'missus' issue to her and I'm now writing this from my hospital bed...;-)....I don't think that was so helpful...:-)
I did the testing both up and down the river in very calm conditions to exclude water/environment.
The motor is a new 60hp Yamaha. It does have a sacrificial trim tab which is offset to the RHS about 8 degrees- this is the recommended setting afaik. Also afaik the trim tab impacts the steering rather than any list/heel.
I undid the bungs after the test and there was no water in hulls.
I've heard back from Brisbane Yamaha and they want the boat back to do their own tests- bring on the unlockdown....given the boat is new not much I want to fiddle with. Anyway will let you all know one day...

Hi guys,
Thanks for all the thoughts, although I suggested the 'missus' issue to her and I'm now writing this from my hospital bed...;-)....I don't think that was so helpful...:-)
I did the testing both up and down the river in very calm conditions to exclude water/environment.
The motor is a new 60hp Yamaha. It does have a sacrificial trim tab which is offset to the RHS about 8 degrees- this is the recommended setting afaik. Also afaik the trim tab impacts the steering rather than any list/heel.
I undid the bungs after the test and there was no water in hulls.
I've heard back from Brisbane Yamaha and they want the boat back to do their own tests- bring on the unlockdown....given the boat is new not much I want to fiddle with. Anyway will let you all know one day...

Hi guys,
Thanks for all the thoughts, although I suggested the 'missus' issue to her and I'm now writing this from my hospital bed...;-)....I don't think that was so helpful...:-)
I did the testing both up and down the river in very calm conditions to exclude water/environment.
The motor is a new 60hp Yamaha. It does have a sacrificial trim tab which is offset to the RHS about 8 degrees- this is the recommended setting afaik. Also afaik the trim tab impacts the steering rather than any list/heel.
I undid the bungs after the test and there was no water in hulls.
I've heard back from Brisbane Yamaha and they want the boat back to do their own tests- bring on the unlockdown....given the boat is new not much I want to fiddle with. Anyway will let you all know one day...

Hi all,
The plot thickens!
Today I removed the electric trolling motor from the front and lifted up the large transducer (I thought that may have been acted like a trim tab as it was on the rear RHS).
Alas, as some of you have already alluded to- these things weren't the cause of the port side heel.
The test I did this morning was in calm water, multiple directions, multiple speeds and using a level to measure the heel/list. This is what I found.
The boat was quite level when stopped. The Level was zero. As speed increased it stayed level until about 33kph when it began to heel. Top speed was about 46kph. It had heeled to port about 5-8 degrees. Reducing speed didn't make much difference until I got below 33kph when the level returned to zero.  The boat came onto plane about 22kph. Coming onto plane didn't seem to cause any heel.  As soon as I got to about 33kph it would heel to about 5-8 degrees and basically remain there as speed went to maximum. I didn't try it with the elect motor installed but that's only going to make it worse if anything. I did the test going upriver and down river on multiple runs. It was very calm with an outgoing tide.
Trim did not make any noticeable difference (as I had thought previously). It may have been that previously as the motor was trimmed out it increased speed and I thought trim was the cause. Today I kept all variables constant, except speed and the heel was remarkably persistent above about 33kph. It may have increased a little from 33kph to 46kph but the level never went above about 8 degrees and variable between 5 and 8.
What was also interesting was that below 33kph the level was remarkably stable around zero.
I can't do anything else and have no idea what might be causing it. I guess there are only two things left- the motor/propeller and the hull. 
Emails have gone to Brisbane Yamaha and Polycraft.
As I mentioned in the email to them, its very disappointing as apart from this problem and another minor one, I really like the boat. 😞
Brisbane Yamaha have replied saying they've forwarded my email to their workshop and will get back to me.
I expect they will need the boat returned.
Anyway, that's where things are currently at and since we are in lockdown here in Brissy now, there's nothing else I can do. 
 
cheers
b
 
 

Hi all,
The plot thickens!
Today I removed the electric trolling motor from the front and lifted up the large transducer (I thought that may have been acted like a trim tab as it was on the rear RHS).
Alas, as some of you have already alluded to- these things weren't the cause of the port side heel.
The test I did this morning was in calm water, multiple directions, multiple speeds and using a level to measure the heel/list. This is what I found.
The boat was quite level when stopped. The Level was zero. As speed increased it stayed level until about 33kph when it began to heel. Top speed was about 46kph. It had heeled to port about 5-8 degrees. Reducing speed didn't make much difference until I got below 33kph when the level returned to zero.  The boat came onto plane about 22kph. Coming onto plane didn't seem to cause any heel.  As soon as I got to about 33kph it would heel to about 5-8 degrees and basically remain there as speed went to maximum. I didn't try it with the elect motor installed but that's only going to make it worse if anything. I did the test going upriver and down river on multiple runs. It was very calm with an outgoing tide.
Trim did not make any noticeable difference (as I had thought previously). It may have been that previously as the motor was trimmed out it increased speed and I thought trim was the cause. Today I kept all variables constant, except speed and the heel was remarkably persistent above about 33kph. It may have increased a little from 33kph to 46kph but the level never went above about 8 degrees and variable between 5 and 8.
What was also interesting was that below 33kph the level was remarkably stable around zero.
I can't do anything else and have no idea what might be causing it. I guess there are only two things left- the motor/propeller and the hull. 
Emails have gone to Brisbane Yamaha and Polycraft.
As I mentioned in the email to them, its very disappointing as apart from this problem and another minor one, I really like the boat. 😞
Brisbane Yamaha have replied saying they've forwarded my email to their workshop and will get back to me.
I expect they will need the boat returned.
Anyway, that's where things are currently at and since we are in lockdown here in Brissy now, there's nothing else I can do. 
 
cheers
b
 
 

Hi all,
The plot thickens!
Today I removed the electric trolling motor from the front and lifted up the large transducer (I thought that may have been acted like a trim tab as it was on the rear RHS).
Alas, as some of you have already alluded to- these things weren't the cause of the port side heel.
The test I did this morning was in calm water, multiple directions, multiple speeds and using a level to measure the heel/list. This is what I found.
The boat was quite level when stopped. The Level was zero. As speed increased it stayed level until about 33kph when it began to heel. Top speed was about 46kph. It had heeled to port about 5-8 degrees. Reducing speed didn't make much difference until I got below 33kph when the level returned to zero.  The boat came onto plane about 22kph. Coming onto plane didn't seem to cause any heel.  As soon as I got to about 33kph it would heel to about 5-8 degrees and basically remain there as speed went to maximum. I didn't try it with the elect motor installed but that's only going to make it worse if anything. I did the test going upriver and down river on multiple runs. It was very calm with an outgoing tide.
Trim did not make any noticeable difference (as I had thought previously). It may have been that previously as the motor was trimmed out it increased speed and I thought trim was the cause. Today I kept all variables constant, except speed and the heel was remarkably persistent above about 33kph. It may have increased a little from 33kph to 46kph but the level never went above about 8 degrees and variable between 5 and 8.
What was also interesting was that below 33kph the level was remarkably stable around zero.
I can't do anything else and have no idea what might be causing it. I guess there are only two things left- the motor/propeller and the hull. 
Emails have gone to Brisbane Yamaha and Polycraft.
As I mentioned in the email to them, its very disappointing as apart from this problem and another minor one, I really like the boat. 😞
Brisbane Yamaha have replied saying they've forwarded my email to their workshop and will get back to me.
I expect they will need the boat returned.
Anyway, that's where things are currently at and since we are in lockdown here in Brissy now, there's nothing else I can do. 
 
cheers
b
 
 

Hi all,
The plot thickens!
Today I removed the electric trolling motor from the front and lifted up the large transducer (I thought that may have been acted like a trim tab as it was on the rear RHS).
Alas, as some of you have already alluded to- these things weren't the cause of the port side heel.
The test I did this morning was in calm water, multiple directions, multiple speeds and using a level to measure the heel/list. This is what I found.
The boat was quite level when stopped. The Level was zero. As speed increased it stayed level until about 33kph when it began to heel. Top speed was about 46kph. It had heeled to port about 5-8 degrees. Reducing speed didn't make much difference until I got below 33kph when the level returned to zero.  The boat came onto plane about 22kph. Coming onto plane didn't seem to cause any heel.  As soon as I got to about 33kph it would heel to about 5-8 degrees and basically remain there as speed went to maximum. I didn't try it with the elect motor installed but that's only going to make it worse if anything. I did the test going upriver and down river on multiple runs. It was very calm with an outgoing tide.
Trim did not make any noticeable difference (as I had thought previously). It may have been that previously as the motor was trimmed out it increased speed and I thought trim was the cause. Today I kept all variables constant, except speed and the heel was remarkably persistent above about 33kph. It may have increased a little from 33kph to 46kph but the level never went above about 8 degrees and variable between 5 and 8.
What was also interesting was that below 33kph the level was remarkably stable around zero.
I can't do anything else and have no idea what might be causing it. I guess there are only two things left- the motor/propeller and the hull. 
Emails have gone to Brisbane Yamaha and Polycraft.
As I mentioned in the email to them, its very disappointing as apart from this problem and another minor one, I really like the boat. 😞
Brisbane Yamaha have replied saying they've forwarded my email to their workshop and will get back to me.
I expect they will need the boat returned.
Anyway, that's where things are currently at and since we are in lockdown here in Brissy now, there's nothing else I can do. 
 
cheers
b
 
 

Hi all,
The plot thickens!
Today I removed the electric trolling motor from the front and lifted up the large transducer (I thought that may have been acted like a trim tab as it was on the rear RHS).
Alas, as some of you have already alluded to- these things weren't the cause of the port side heel.
The test I did this morning was in calm water, multiple directions, multiple speeds and using a level to measure the heel/list. This is what I found.
The boat was quite level when stopped. The Level was zero. As speed increased it stayed level until about 33kph when it began to heel. Top speed was about 46kph. It had heeled to port about 5-8 degrees. Reducing speed didn't make much difference until I got below 33kph when the level returned to zero.  The boat came onto plane about 22kph. Coming onto plane didn't seem to cause any heel.  As soon as I got to about 33kph it would heel to about 5-8 degrees and basically remain there as speed went to maximum. I didn't try it with the elect motor installed but that's only going to make it worse if anything. I did the test going upriver and down river on multiple runs. It was very calm with an outgoing tide.
Trim did not make any noticeable difference (as I had thought previously). It may have been that previously as the motor was trimmed out it increased speed and I thought trim was the cause. Today I kept all variables constant, except speed and the heel was remarkably persistent above about 33kph. It may have increased a little from 33kph to 46kph but the level never went above about 8 degrees and variable between 5 and 8.
What was also interesting was that below 33kph the level was remarkably stable around zero.
I can't do anything else and have no idea what might be causing it. I guess there are only two things left- the motor/propeller and the hull. 
Emails have gone to Brisbane Yamaha and Polycraft.
As I mentioned in the email to them, its very disappointing as apart from this problem and another minor one, I really like the boat. 😞
Brisbane Yamaha have replied saying they've forwarded my email to their workshop and will get back to me.
I expect they will need the boat returned.
Anyway, that's where things are currently at and since we are in lockdown here in Brissy now, there's nothing else I can do. 
 
cheers
b
 
 

Hi all,
The plot thickens!
Today I removed the electric trolling motor from the front and lifted up the large transducer (I thought that may have been acted like a trim tab as it was on the rear RHS).
Alas, as some of you have already alluded to- these things weren't the cause of the port side heel.
The test I did this morning was in calm water, multiple directions, multiple speeds and using a level to measure the heel/list. This is what I found.
The boat was quite level when stopped. The Level was zero. As speed increased it stayed level until about 33kph when it began to heel. Top speed was about 46kph. It had heeled to port about 5-8 degrees. Reducing speed didn't make much difference until I got below 33kph when the level returned to zero.  The boat came onto plane about 22kph. Coming onto plane didn't seem to cause any heel.  As soon as I got to about 33kph it would heel to about 5-8 degrees and basically remain there as speed went to maximum. I didn't try it with the elect motor installed but that's only going to make it worse if anything. I did the test going upriver and down river on multiple runs. It was very calm with an outgoing tide.
Trim did not make any noticeable difference (as I had thought previously). It may have been that previously as the motor was trimmed out it increased speed and I thought trim was the cause. Today I kept all variables constant, except speed and the heel was remarkably persistent above about 33kph. It may have increased a little from 33kph to 46kph but the level never went above about 8 degrees and variable between 5 and 8.
What was also interesting was that below 33kph the level was remarkably stable around zero.
I can't do anything else and have no idea what might be causing it. I guess there are only two things left- the motor/propeller and the hull. 
Emails have gone to Brisbane Yamaha and Polycraft.
As I mentioned in the email to them, its very disappointing as apart from this problem and another minor one, I really like the boat. 😞
Brisbane Yamaha have replied saying they've forwarded my email to their workshop and will get back to me.
I expect they will need the boat returned.
Anyway, that's where things are currently at and since we are in lockdown here in Brissy now, there's nothing else I can do. 
 
cheers
b
 
 

Here you go. Did a test today off Manly. 10kph wind from the E smack in the middle of an outgoing tide. Boat facing into wind. (kph is kilometers per hour)
I used a clamp meter at the battery.
Rabbit mode/10= 43 amps (draw)= 4kph (boat speed over ground)
8=24amps= 3.2kph
7=18amps=2.6kph
6=12amps=2.4kph
5=8amps=1.93kph
4=4.8amps=1.44kph
3=2.7amps=1.12kph
2=1.1amps=0.8kph
1=0.5amps=0.5kph
On the anchor lock, as you'd expect, current draw varied. Today it was from 0-5amps- this is going to be much dependent on wind and current. If there's no current and no wind then you'd expect the motor to draw zero current. If its blowing a gale with a current its going to draw 43amps (and it still may not hold your position).
If you have a 120amp battery and you only want to go to 80% discharge you have 24amps so on rabbit mode you'd get half an hour or about 2k.
If on 5, you'd get about 3hrs and about 6k.
On anchor lock you'd get quite a few hours, but as mentioned its going to be a function of wind and current. If it consistently drew 2.5 amps then you'd get about 10hours.
Done!
Now I just need to catch some fish and/or go boat camping. :-)
 
 

Thanks all,
For those, like me, who are learners...'Listing' refers to a boat leaning off centre- left or right, due to something within the boat (like cargo distributed more to one side than the other). While 'Heeling' refers to a boat leaning off centre due to some external (like wind).
I found this link helpful (as well as all your comments)
https://www.boatingmag.com/how-to/tips-to-alleviate-lean-list-and-heel/
 
I also note that the electric motor is on the LHS along with the battery. Its a polycraft model with two consoles and so the captain console is on the RHS, which should offset the motor. The bait tank is on the LHS too but was empty when I experienced the List.
Anyway, until I get out and test the trim and weight distribution the discussion is academic but still useful for my learning.
Thanks again.

Thanks all,
For those, like me, who are learners...'Listing' refers to a boat leaning off centre- left or right, due to something within the boat (like cargo distributed more to one side than the other). While 'Heeling' refers to a boat leaning off centre due to some external (like wind).
I found this link helpful (as well as all your comments)
https://www.boatingmag.com/how-to/tips-to-alleviate-lean-list-and-heel/
 
I also note that the electric motor is on the LHS along with the battery. Its a polycraft model with two consoles and so the captain console is on the RHS, which should offset the motor. The bait tank is on the LHS too but was empty when I experienced the List.
Anyway, until I get out and test the trim and weight distribution the discussion is academic but still useful for my learning.
Thanks again.

Thanks all,
For those, like me, who are learners...'Listing' refers to a boat leaning off centre- left or right, due to something within the boat (like cargo distributed more to one side than the other). While 'Heeling' refers to a boat leaning off centre due to some external (like wind).
I found this link helpful (as well as all your comments)
https://www.boatingmag.com/how-to/tips-to-alleviate-lean-list-and-heel/
 
I also note that the electric motor is on the LHS along with the battery. Its a polycraft model with two consoles and so the captain console is on the RHS, which should offset the motor. The bait tank is on the LHS too but was empty when I experienced the List.
Anyway, until I get out and test the trim and weight distribution the discussion is academic but still useful for my learning.
Thanks again.

Here you go. Did a test today off Manly. 10kph wind from the E smack in the middle of an outgoing tide. Boat facing into wind. (kph is kilometers per hour)
I used a clamp meter at the battery.
Rabbit mode/10= 43 amps (draw)= 4kph (boat speed over ground)
8=24amps= 3.2kph
7=18amps=2.6kph
6=12amps=2.4kph
5=8amps=1.93kph
4=4.8amps=1.44kph
3=2.7amps=1.12kph
2=1.1amps=0.8kph
1=0.5amps=0.5kph
On the anchor lock, as you'd expect, current draw varied. Today it was from 0-5amps- this is going to be much dependent on wind and current. If there's no current and no wind then you'd expect the motor to draw zero current. If its blowing a gale with a current its going to draw 43amps (and it still may not hold your position).
If you have a 120amp battery and you only want to go to 80% discharge you have 24amps so on rabbit mode you'd get half an hour or about 2k.
If on 5, you'd get about 3hrs and about 6k.
On anchor lock you'd get quite a few hours, but as mentioned its going to be a function of wind and current. If it consistently drew 2.5 amps then you'd get about 10hours.
Done!
Now I just need to catch some fish and/or go boat camping. :-)
 
 

Here you go. Did a test today off Manly. 10kph wind from the E smack in the middle of an outgoing tide. Boat facing into wind. (kph is kilometers per hour)
I used a clamp meter at the battery.
Rabbit mode/10= 43 amps (draw)= 4kph (boat speed over ground)
8=24amps= 3.2kph
7=18amps=2.6kph
6=12amps=2.4kph
5=8amps=1.93kph
4=4.8amps=1.44kph
3=2.7amps=1.12kph
2=1.1amps=0.8kph
1=0.5amps=0.5kph
On the anchor lock, as you'd expect, current draw varied. Today it was from 0-5amps- this is going to be much dependent on wind and current. If there's no current and no wind then you'd expect the motor to draw zero current. If its blowing a gale with a current its going to draw 43amps (and it still may not hold your position).
If you have a 120amp battery and you only want to go to 80% discharge you have 24amps so on rabbit mode you'd get half an hour or about 2k.
If on 5, you'd get about 3hrs and about 6k.
On anchor lock you'd get quite a few hours, but as mentioned its going to be a function of wind and current. If it consistently drew 2.5 amps then you'd get about 10hours.
Done!
Now I just need to catch some fish and/or go boat camping. :-)
 
 

Here you go. Did a test today off Manly. 10kph wind from the E smack in the middle of an outgoing tide. Boat facing into wind. (kph is kilometers per hour)
I used a clamp meter at the battery.
Rabbit mode/10= 43 amps (draw)= 4kph (boat speed over ground)
8=24amps= 3.2kph
7=18amps=2.6kph
6=12amps=2.4kph
5=8amps=1.93kph
4=4.8amps=1.44kph
3=2.7amps=1.12kph
2=1.1amps=0.8kph
1=0.5amps=0.5kph
On the anchor lock, as you'd expect, current draw varied. Today it was from 0-5amps- this is going to be much dependent on wind and current. If there's no current and no wind then you'd expect the motor to draw zero current. If its blowing a gale with a current its going to draw 43amps (and it still may not hold your position).
If you have a 120amp battery and you only want to go to 80% discharge you have 24amps so on rabbit mode you'd get half an hour or about 2k.
If on 5, you'd get about 3hrs and about 6k.
On anchor lock you'd get quite a few hours, but as mentioned its going to be a function of wind and current. If it consistently drew 2.5 amps then you'd get about 10hours.
Done!
Now I just need to catch some fish and/or go boat camping. :-)
 
 

Bugger x 2...I thought Tues is going to be good- wind is perfect...got excited...then looked at my diary...:-(...client's...client's...client's...I'm going to have to have a serious talk to my secretary...I mean, surely she can schedule clients on non-fishing days?
I am so keen to do an over-nighter...new boat and all...sigh...
 

Bugger x 2...I thought Tues is going to be good- wind is perfect...got excited...then looked at my diary...:-(...client's...client's...client's...I'm going to have to have a serious talk to my secretary...I mean, surely she can schedule clients on non-fishing days?
I am so keen to do an over-nighter...new boat and all...sigh...
 

Most sounders have a voltmeter which will tell you battery voltage. Mind you, not much good if your electric motor is on a different circuit. 🙂
This is the voltages discharges:
% of Charge (discharged DOD)             Volts
100              0                               12.7
90                10                             12.58
80                20                             12.46
75                 25                           12.40
70                 30                         12.36
65                 35                         12.32
60                  40                       12.28
50                   50                       12.20
Discharged   >50                     11.90
My minn has a battery level indicator. I found this:
"For my motor, four is 12.8v or better, three lights is 12.6v two, 12.5, and one light is 12.3v. "
If true, then the lowest light indicates about 60-65% of charge, which makes sense.
As ellicat implies- easy enough to get an inline voltmeter - Jcar or something similar sell them.
Raises a question of how long your deep cycle battery would last if discharged regularly...probably depends upon the type and quality of battery and how long it was left discharged.
How long is a piece of string?
However a mate of mine had a deep cycle last 10yrs from carefully managing it. I also read a marine battery has an expected life of 1-6yrs. I expect if you discharge to more than 50% regularly its going to be 1yr, and 6yrs if you don't go below 80% or thereabouts and recharge soon after discharge.
I found this:
"Battery life is directly related to how deep the battery is cycled each time. If a battery is discharged to 50% every day, it will last about twice as long as if it is cycled to 80% DOD. If cycled only 10% DOD, it will last about 5 times as long as one cycled to 50%. Obviously, there are some practical limitations on this - you don't usually want to have a 5 ton pile of batteries sitting there just to reduce the DOD. The most practical number to use is 50% DOD on a regular basis. This does NOT mean you cannot go to 80% once in a while. It's just that when designing a system when you have some idea of the loads, you should figure on an average DOD of around 50% for the best storage vs cost factor. Also, there is an upper limit - a battery that is continually cycled 5% or less will usually not last as long as one cycled down 10%. This happens because at very shallow cycles, the Lead Dioxide tends to build up in clumps on the the positive plates rather in an even film. The graph above shows how lifespan is affected by depth of discharge. The chart is for a Concorde Lifeline battery, but all lead-acid batteries will be similar in the shape of the curve, although the number of cycles will vary."
 
Cheers
B

Most sounders have a voltmeter which will tell you battery voltage. Mind you, not much good if your electric motor is on a different circuit. 🙂
This is the voltages discharges:
% of Charge (discharged DOD)             Volts
100              0                               12.7
90                10                             12.58
80                20                             12.46
75                 25                           12.40
70                 30                         12.36
65                 35                         12.32
60                  40                       12.28
50                   50                       12.20
Discharged   >50                     11.90
My minn has a battery level indicator. I found this:
"For my motor, four is 12.8v or better, three lights is 12.6v two, 12.5, and one light is 12.3v. "
If true, then the lowest light indicates about 60-65% of charge, which makes sense.
As ellicat implies- easy enough to get an inline voltmeter - Jcar or something similar sell them.
Raises a question of how long your deep cycle battery would last if discharged regularly...probably depends upon the type and quality of battery and how long it was left discharged.
How long is a piece of string?
However a mate of mine had a deep cycle last 10yrs from carefully managing it. I also read a marine battery has an expected life of 1-6yrs. I expect if you discharge to more than 50% regularly its going to be 1yr, and 6yrs if you don't go below 80% or thereabouts and recharge soon after discharge.
I found this:
"Battery life is directly related to how deep the battery is cycled each time. If a battery is discharged to 50% every day, it will last about twice as long as if it is cycled to 80% DOD. If cycled only 10% DOD, it will last about 5 times as long as one cycled to 50%. Obviously, there are some practical limitations on this - you don't usually want to have a 5 ton pile of batteries sitting there just to reduce the DOD. The most practical number to use is 50% DOD on a regular basis. This does NOT mean you cannot go to 80% once in a while. It's just that when designing a system when you have some idea of the loads, you should figure on an average DOD of around 50% for the best storage vs cost factor. Also, there is an upper limit - a battery that is continually cycled 5% or less will usually not last as long as one cycled down 10%. This happens because at very shallow cycles, the Lead Dioxide tends to build up in clumps on the the positive plates rather in an even film. The graph above shows how lifespan is affected by depth of discharge. The chart is for a Concorde Lifeline battery, but all lead-acid batteries will be similar in the shape of the curve, although the number of cycles will vary."
 
Cheers
B

Bugger x 2...I thought Tues is going to be good- wind is perfect...got excited...then looked at my diary...:-(...client's...client's...client's...I'm going to have to have a serious talk to my secretary...I mean, surely she can schedule clients on non-fishing days?
I am so keen to do an over-nighter...new boat and all...sigh...
 

Most sounders have a voltmeter which will tell you battery voltage. Mind you, not much good if your electric motor is on a different circuit. 🙂
This is the voltages discharges:
% of Charge (discharged DOD)             Volts
100              0                               12.7
90                10                             12.58
80                20                             12.46
75                 25                           12.40
70                 30                         12.36
65                 35                         12.32
60                  40                       12.28
50                   50                       12.20
Discharged   >50                     11.90
My minn has a battery level indicator. I found this:
"For my motor, four is 12.8v or better, three lights is 12.6v two, 12.5, and one light is 12.3v. "
If true, then the lowest light indicates about 60-65% of charge, which makes sense.
As ellicat implies- easy enough to get an inline voltmeter - Jcar or something similar sell them.
Raises a question of how long your deep cycle battery would last if discharged regularly...probably depends upon the type and quality of battery and how long it was left discharged.
How long is a piece of string?
However a mate of mine had a deep cycle last 10yrs from carefully managing it. I also read a marine battery has an expected life of 1-6yrs. I expect if you discharge to more than 50% regularly its going to be 1yr, and 6yrs if you don't go below 80% or thereabouts and recharge soon after discharge.
I found this:
"Battery life is directly related to how deep the battery is cycled each time. If a battery is discharged to 50% every day, it will last about twice as long as if it is cycled to 80% DOD. If cycled only 10% DOD, it will last about 5 times as long as one cycled to 50%. Obviously, there are some practical limitations on this - you don't usually want to have a 5 ton pile of batteries sitting there just to reduce the DOD. The most practical number to use is 50% DOD on a regular basis. This does NOT mean you cannot go to 80% once in a while. It's just that when designing a system when you have some idea of the loads, you should figure on an average DOD of around 50% for the best storage vs cost factor. Also, there is an upper limit - a battery that is continually cycled 5% or less will usually not last as long as one cycled down 10%. This happens because at very shallow cycles, the Lead Dioxide tends to build up in clumps on the the positive plates rather in an even film. The graph above shows how lifespan is affected by depth of discharge. The chart is for a Concorde Lifeline battery, but all lead-acid batteries will be similar in the shape of the curve, although the number of cycles will vary."
 
Cheers
B