Mod needed to keep boat on but can't put in gear

[The Hulk]

lets say you have a 12v 100A battery for easy math = 1200w power (not really because after 50% you dont have power for a boat/car anyway)

you have a 12v jump pack lithium so slightly higher voltage (which is a major key in why they work for the starter motors) higher voltage = faster speed on motors... 

say you have a 10A jump pack battery (yes i know they all say something like 12v 400A) marketing gimmick for ability to supply up to 400A peak for a split second but that is NOT 400A capacity otherwise it would be 4X the size of your boat battery.

most jump packs are liFePo4 cells so roughly fully charged pretty close to 15v depending on make/model.  10A * nominal  (12.8v) = 128w for a decently sized jumper, and good luck finding any jump pack to list the "actual" battery capacity rather than peak supply current.. 

our dead battery is 1200w capacity and lets say its 50% dead and cant start the boat, now you connect a jump pack and have 128w of useful power to put into a 1200w battery, however you cant put the full power into the dead battery once the voltage of jump pack comes down equal to that of the dead battery. (takes higher voltage to push energy into the battery) 

so you have basically barely charged your dead battery and depleted your jump pack. This is why connecting a lead-acid jump pack (older style) is an absolute terrible idea because peak supply current on a small LA battery is very low compared to todays jump packs and the load of dead battery brings down the jump packs ability to supply the load of starter motor. (its similar) with Litihum jump packs but since they can supply a larger load it sometimes works. 

i've seen instructions on many of these cheap jump packs and it states disconnecting the positive cable and connect jump pack without dead battery in the equation until it starts. 

[ahopkins22LSV]

I have never heard of that in any application, it sounds like a great way to really mess something up or give yourself a nice shock!

[The Hulk]

22 minutes ago, ahopkinsVTX said:

I have never heard of that in any application, it sounds like a great way to really mess something up or give yourself a nice shock!

the better solution is to buy a bigger more $$ 100-200 lithium jump pack to be safe and not have to do any of the above.  some of the nicer ones dont supply power until the button is pushed which allows you to get things connected before pushing the button and starting right after. 

Edited March 1, 2019 by The Hulk

[oldjeep]

40 minutes ago, The Hulk said:

lets say you have a 12v 100A battery for easy math = 1200w power (not really because after 50% you dont have power for a boat/car anyway)

you have a 12v jump pack lithium so slightly higher voltage (which is a major key in why they work for the starter motors) higher voltage = faster speed on motors... 

say you have a 10A jump pack battery (yes i know they all say something like 12v 400A) marketing gimmick for ability to supply up to 400A peak for a split second but that is NOT 400A capacity otherwise it would be 4X the size of your boat battery.

most jump packs are liFePo4 cells so roughly fully charged pretty close to 15v depending on make/model.  10A * nominal  (12.8v) = 128w for a decently sized jumper, and good luck finding any jump pack to list the "actual" battery capacity rather than peak supply current.. 

our dead battery is 1200w capacity and lets say its 50% dead and cant start the boat, now you connect a jump pack and have 128w of useful power to put into a 1200w battery, however you cant put the full power into the dead battery once the voltage of jump pack comes down equal to that of the dead battery. (takes higher voltage to push energy into the battery) 

so you have basically barely charged your dead battery and depleted your jump pack. This is why connecting a lead-acid jump pack (older style) is an absolute terrible idea because peak supply current on a small LA battery is very low compared to todays jump packs and the load of dead battery brings down the jump packs ability to supply the load of starter motor. (its similar) with Litihum jump packs but since they can supply a larger load it sometimes works. 

i've seen instructions on many of these cheap jump packs and it states disconnecting the positive cable and connect jump pack without dead battery in the equation until it starts. 

It that works for you then go for it.  Used my jump pack on many occasions and never had an issue. 

I'd love to see a picture of these instructions that are telling you to disconnect the battery.

 

[Falko]

I've always been told to never disconnect a battery to jump it, unless that battery is shorted/dead-dead and it can harm the jumping battery/charging system. The re-connection of the battery can damage the charging system with the instant big draw. Any truths to that??

OR

You could always do what an old 200hp outboard I had once did. They supplied a pull cord in the event the battery went dead. SHould have supplied a gym membership too...

Edited March 1, 2019 by Falko

[shawndoggy]

Hulk I'm pretty sure you must be a descendant of Rube Goldberg?

You are inventing a complicated solution where there's an easy one. 

Just add another battery (or two).  You can get a group 29 deep cycle for about $110.  If you currently have the two factory Group 24s that most boats get spec'd with, that will double your reserve capacity.  Even better, just replace your two group 24s with two group 29s.  I had my dealer do this before I took delivery, and the two G29s fit under the observer's seat, just like the G24s (the battery box cleats do need to get moved a little).  Keep them charged and topped up when not in use with a shore charger.  For polite stereo useage, that's going to be plenty.

If you need to be "that guy" at the sandbar that thinks that everyone wants to (or at least needs to) hear all of your music, then you're going to need to come up with a more elaborate solution ... which is still going to involve either more reserve capacity or an alternator that's going to deliver a real charge at idle.

[shawndoggy]

1 hour ago, The Hulk said:

lets say you have a 12v 100A battery for easy math = 1200w power (not really because after 50% you dont have power for a boat/car anyway)

you have a 12v jump pack lithium so slightly higher voltage (which is a major key in why they work for the starter motors) higher voltage = faster speed on motors... 

say you have a 10A jump pack battery (yes i know they all say something like 12v 400A) marketing gimmick for ability to supply up to 400A peak for a split second but that is NOT 400A capacity otherwise it would be 4X the size of your boat battery.

most jump packs are liFePo4 cells so roughly fully charged pretty close to 15v depending on make/model.  10A * nominal  (12.8v) = 128w for a decently sized jumper, and good luck finding any jump pack to list the "actual" battery capacity rather than peak supply current.. 

our dead battery is 1200w capacity and lets say its 50% dead and cant start the boat, now you connect a jump pack and have 128w of useful power to put into a 1200w battery, however you cant put the full power into the dead battery once the voltage of jump pack comes down equal to that of the dead battery. (takes higher voltage to push energy into the battery) 

so you have basically barely charged your dead battery and depleted your jump pack. This is why connecting a lead-acid jump pack (older style) is an absolute terrible idea because peak supply current on a small LA battery is very low compared to todays jump packs and the load of dead battery brings down the jump packs ability to supply the load of starter motor. (its similar) with Litihum jump packs but since they can supply a larger load it sometimes works. 

i've seen instructions on many of these cheap jump packs and it states disconnecting the positive cable and connect jump pack without dead battery in the equation until it starts. 

The question this begs to me is why, when you have two batteries, do you have a depleted starting battery in the first place?

[Skymedic]

If one were to decide to upgrade their alternator, is the factory wiring sufficient? Was looking at the DB Electrical high output. 

Edited March 1, 2019 by Skymedic

[oldjeep]

11 minutes ago, Skymedic said:

If one were to decide to upgrade their alternator, is the factory wiring sufficient? Was looking at the DB Electrical high output. 

Doubt it.   This chart says that you would need a 2 gauge or 0 for a 220 amp alternator.   I'd suspect that the stock wiring is 4 gauge at best.

 

https://alternatorparts.com/wire-size-chart.html

[Skymedic]

Awesome. Thanks for your help. 

[The Hulk]

4 hours ago, shawndoggy said:

The question this begs to me is why, when you have two batteries, do you have a depleted starting battery in the first place?

I had somebody install an ACR and I think it failed last year and I never got around to him fixing and replacing it so that's #1 as well going to grp 27 or 29, if the ACR was working properly I would not have had any issues cuz I could have just kept it on battery one. 

I have the blue seas model any other recommendations?

[shawndoggy]

14 minutes ago, The Hulk said:

I had somebody install an ACR and I think it failed last year and I never got around to him fixing and replacing it so that's #1 as well going to grp 27 or 29, if the ACR was working properly I would not have had any issues cuz I could have just kept it on battery one. 

I have the blue seas model any other recommendations?

I guess I'd recommend double checking the wiring and making sure it's wired up right.  It's pretty idiotproof if wired correctly.

[oldjeep]

32 minutes ago, shawndoggy said:

I guess I'd recommend double checking the wiring and making sure it's wired up right.  It's pretty idiotproof if wired correctly.

Number one mistake that everyone makes is not running the ground wire to the ACR

[The Hulk]

1 hour ago, oldjeep said:

Number one mistake that everyone makes is not running the ground wire to the ACR

I looked in there and it was not connected or fell off I put it back on but the light flashed and then never flashed again so im thinking it's toast. Should have installed myself $$#$@ 

[oldjeep]

17 minutes ago, The Hulk said:

I looked in there and it was not connected or fell off I put it back on but the light flashed and then never flashed again so im thinking it's toast. Should have installed myself $$#$@ 

Pretty hard to burn one out even if you do something silly like wire it up with the batteries connected.  Id double check all the connections before assuming it is fried. 

https://www.bluesea.com/viewresource/1368

 

Edited March 1, 2019 by oldjeep

[ahopkins22LSV]

When did you notice this ground issue? Did you damage your batteries?

[The Hulk]

Noticed when I'd left on bat 1 killed it flipped over to 2 and it was dead as well. Started looking at that device didn't see the light flashing and found where somebody installed it the ground wire wasn't connected.. I reconnected it and played around with it and followed a few of the instructions but can never get it to come on tried turning on and off and couldn't get the voltages to work

In reading the instructions again are those voltage is measured when connected to the battery or when the ACR is not connected to the battery and only grounded?

if they are when connected to the battery and your battery is below 10.8 volts am I to understand it will not charge then so it is a pointless device? 

[oldjeep]

How would you get a voltage with only ground connected? 

The idea of the device is not to allow you to drain the crap out of a battery.   Your use case would be better with an a/b switch.  Use one for noise and one to get home.  

[shawndoggy]

21 minutes ago, The Hulk said:

Noticed when I'd left on bat 1 killed it flipped over to 2 and it was dead as well. Started looking at that device didn't see the light flashing and found where somebody installed it the ground wire wasn't connected.. I reconnected it and played around with it and followed a few of the instructions but can never get it to come on tried turning on and off and couldn't get the voltages to work

In reading the instructions again are those voltage is measured when connected to the battery or when the ACR is not connected to the battery and only grounded?

if they are when connected to the battery and your battery is below 10.8 volts am I to understand it will not charge then so it is a pointless device? 

Why do you even have a batt 1 / batt 2 switch?  You should have an ON-OFF—COMBINE switch. 

Yeah and uh... as an engineer you should know that it’s not gonna work without connecting the ground. 

You might also consider trying all of the instructions instead of just a few. 

Edited March 2, 2019 by shawndoggy
Bad spellin

[DUKENO1]

I made that mistake when I first installed my add a battery kit.  I initially ran a white ground wire just to make sure everything worked (had ran out of black wire).  When I finished I pulled off the temporary ground with the intentions of replacing with the proper color.  Of course I forgot and went several weeks and didn't figure it out till my stereo started cutting out one day. I got it fixed up but stereo battery ended up crapping out early as a result.

 

[The Hulk]

27 minutes ago, shawndoggy said:

Why do you even have a batt 1 / batt 2 switch?  You should have an ON-OFF—COMBINE switch. 

Yeah and uh... as an engineer you should know that it’s not gonna work without connecting the ground. 

You might also consider trying all of the instructions instead of just a few. 

yeah I knew it wasn't working when I saw the ground not connected I then follow the troubleshooting connection and determine that is bad.. I'm having it replaced although I don't have the boat but I'm definitely going to check when I get it back this time.

The switch was still the standard one installed one or two or one plus two or off.

It was the end of the season so was just going to inform dealer to fix it when I took it in but now I'm questioning if in fact it was connected right maybe the house and auxiliary battery were backwards who knows. Checking the wiring is on the pre-launch checklist this year.. along with new larger batteries. 

In thinking further it could also be the fact that we only have a short trip back to the dock so by the time the starter battery gets fully charged and the ACR kicks over to auxiliary it hardly charged at all and the 5-8 minute trip home each time.. 

Edited March 2, 2019 by The Hulk

[shawndoggy]

1 minute ago, The Hulk said:

yeah I knew it wasn't working when I saw the ground not connected I then follow the troubleshooting connection and determine that is bad.. I'm having it replaced although I don't have the boat but I'm definitely going to check when I get it back this time.

It might not be bad tho.  Even if hooked up properly, it's not going to combine a batt that's at 9.6v with your other battery.  It's a failsafe protection to keep you from wrecking your battery and your alternator.  So charge both batts with a shore charger and make sure they are both above 12v, THEN test whether it works.

And post a diagram of how you have it wired with a 1-2-all-off switch.  That could also be problematic.

[The Hulk]

7 minutes ago, shawndoggy said:

It might not be bad tho.  Even if hooked up properly, it's not going to combine a batt that's at 9.6v with your other battery.  It's a failsafe protection to keep you from wrecking your battery and your alternator.  So charge both batts with a shore charger and make sure they are both above 12v, THEN test whether it works.

And post a diagram of how you have it wired with a 1-2-all-off switch.  That could also be problematic.

Boat is 3 hours away I meant to take a picture before I dropped it off to see if they had wired it incorrectly.. and I forgot. All I know it was definitely fubar and it's definitely going to need checked or rewired properly.. 

I as well thought they were replacing the switch.. but didn't seem so, but now thinking out about it maybe they put it in between the combine mode so ACR is the combiner.. I don't know pointless to speculate how they wired it until I get it back

Edited March 2, 2019 by The Hulk

[The Hulk]

On 3/2/2019 at 11:35 AM, shawndoggy said:

And post a diagram of how you have it wired with a 1-2-all-off switch.  That could also be problematic.

just got word that dealer found the issue, battery switch internal contacts were 180 off and internal mounts stripped, switch had to be replaced. Guess that answers a few other VERY (odd situations) with the switch and battery not charging last summer... anyhow all fixed and ACR is now functioning and was not damaged thankfully. 

 

 

[shawndoggy]

1 minute ago, The Hulk said:

just got word that dealer found the issue, battery switch internal contacts were 180 off and internal mounts stripped, switch had to be replaced. Guess that answers a few other VERY (odd situations) with the switch and battery not charging last summer... anyhow all fixed and ACR is now functioning and was not damaged thankfully. 

Still tho... can you post a diagram of how it's wired with a 1-2-ALL-OFF switch?  I've never been able to work out how that could work with the blue seas acr.