Check your batteries.

[Capt’n Ron]

This may be obvious information to many, but not everyone may know this.  Your motor/starting battery and your house battery (or house bank) should be different battery types!  Your starter should be a good crank battery whereas the house battery should be deep cycle, AGM, or lithium.  

The reason I mention is because there have been some new boats delivered with crank batteries only for both starter and house. If this is the case, contact your dealer. 

I’d also recommend if you haven’t already done so, learn about your boat batteries, types, amp hours (Ah),voltage, charging system, discharge levels, inverter (if you have one or want one) AC and DC electrical, and what the Ah run is for each device. This will help ensure you do not find yourself stranded with dead batteries, or having to replace them too soon!  

I don’t claim to be a marine electrical expert, but what I’ve learned is an important aspect of happy boating. 

Cheers,
Ron

[lynnardm]

Capt’n Ron,

It turns out the engine and house battery in my new (last summer) 895 are both the same (engine crank/start). I was shocked. This is one thing I didn’t think to check in my initial inspection. I’ll be going back to my dealer and asking them to get me a house battery. What got me looking at batteries is that the battery for the bow thruster just went dead. I don’t yet know what’s going on with that as it’s just come up

Capt’n Lynn

[Capt’n Ron]

I ended up having to add a dedicated charger for my bow thruster battery. Would be interesting to know if anyone else is having issues with their bow thruster battery?

[CruisingCascadia]

Capt'n Ron, the same thing happened to us with our mf855. The fridge killed one of our starter batteries on our way to Desolation Sound last year. Now with our new nc895 our heater is killing our starter battery even though we have a 4 battery house bank (that it was supposed to be connected to).
Also, the battery charger for the starter batteries is connected through our inverter so if we disconnect from shore power and turn on the inverter the starter battery charger uses the inverter to charge the starter batteries from the house bank.
We are going to get an electrical audit done and talk to Sundance after we know what is going on.
Weon't want any surprises.

[jlasail]

On the same subject, the bow thruster batteries (2), died after only 3 seasons. The other batteries (all acid based), are all still fine after 5 years. Boat: 2014 SO409.

[Capt’n Ron]

Good idea to get an electrical audit, something isn’t right. Do you have a battery monitor and a voltage meter?  I just installed the Victron 712 last week so I was able to determine my run Ahs. My refridge uses about 90A over 24 hours, so if you are not monitoring closely you can drain your battery bank while anchored.  

I’ve also had a lot of electrical issues over the past three years and Sundance has spent a lot of time fixing them, but I have still had issues with my inverter. After talking to Victron reps at the Seattle boat show a couple weeks ago they determined my battery bank was still not wired correctly and the wrong inverter was installed for the loads I run, my Keurig.    Turns out a modified sine wave inverter was installed instead of a pure sine wave inverter, so I’m looking to have to replace it. I fixed my battery bank wiring when I installed the Victron. 

The good out of all of this is I’ve learned a lot about electrical that I probably needed to know anyway. 

[Capt’n Ron]

Just some clarification on battery types. Your engine batteries should be starting (crank) type and your house batteries should be a deep cycle type, which handle discharge and recharge cycles much better as well as other important features. House batteries would include: flooded, AGM, Gel, and Lithium. They each have pros and cons so do your research, but from what I’ve found AGM batteries seem to be the preferred, but they are expensive! I’m sure there are experienced owners on the forum that can share their thoughts as well.

You should also pay attention to keeping your batteries charged through the winter months when you may not be using your boat as much and the batteries getting charged. Batteries will have some level of discharge just sitting idle so you could find yourself with dead batteries when you are looking to head out on the water. A good thing to understand is the charge level of your battery as it may not be what you think. Here is a general guideline I found on-line:

100% charge = 12.6-12.7 volt for flooded, 12.8-12.9 for AGM
75% charge = 12.4 flooded, 12.65 AGM
50% charge = 12.2 flooded, 12.35 AGM
25% charge = 12.0 flooded, 12.0 AGM
0% dead = 11.8 flooded, 11.8 AGM

Get your voltage meter out and check your levels when the battery is not under charge, and as a general rule don't let a battery level drop below 50%. There is a lot more to know about batteries and boat electrical than what I've posted, so dig in and learn and share.  

Also, don't forget to check your bow thruster battery when its under charge and when it's not being charged.  The reason is if your bow thruster battery is being charged by the house battery charger, it could be you are experiencing voltage loss if the cable from the charger to the battery is not properly sized for the distance. If that's the case then your battery is not getting fully charged and would lead to undercharge or dead battery and could result in having to replace it sooner than needed. I believe the maximum acceptable loss is 10%, but 3% is recommended. So if your charger is putting out 14.1 volts and you have a 10% loss at the battery, that means your battery is only getting 12.69 volt charge and is right at the edge of acceptable. You can either run a bigger gage wire from the charger or add a dedicated charger for the thruster battery. This is a problem I had so a dedicated charger was added and I've not had an issue since.

[lynnardm]

Feb 15, 2019 3:45:38 GMT lynnardm said:

Capt’n Ron,

It turns out the engine and house battery in my new (last summer) 895 are both the same (engine crank/start). I was shocked. This is one thing I didn’t think to check in my initial inspection. I’ll be going back to my dealer and asking them to get me a house battery. What got me looking at batteries is that the battery for the bow thruster just went dead. I don’t yet know what’s going on with that as it’s just come up

Capt’n Lynn

Here is an update on my (895) bow thruster battery.  The boat is always on shore power or being run with the engine. I hooked up a trickle charger a few days ago and this charged the battery and at this point it has held a charge for 2 days at the dock.  I measured the volts at the battery when connected to shore power and the reading is 12.57 volts. Capt'n Ron (my electrical expert :')  has advised that this indicates that the charge voltage at the battery is too low to adequately charge the battery.  I've notified Sundance of this problem and of the problem of an incorrect house battery.

Captn Lynn

[Nick Buck-Niehaus]

Feb 15, 2019 0:14:37 GMT Capt’n Ron said:

This may be obvious information to many, but not everyone may know this.  Your motor/starting battery and your house battery (or house bank) should be different battery types!  Your starter should be a good crank battery whereas the house battery should be deep cycle, AGM, or lithium.  

The reason I mention is because there have been some new boats delivered with crank batteries only for both starter and house. If this is the case, contact your dealer. 

I’d also recommend if you haven’t already done so, learn about your boat batteries, types, amp hours (Ah),voltage, charging system, discharge levels, inverter (if you have one or want one) AC and DC electrical, and what the Ah run is for each device. This will help ensure you do not find yourself stranded with dead batteries, or having to replace them too soon!  

I don’t claim to be a marine electrical expert, but what I’ve learned is an important aspect of happy boating. 

Cheers,
Ron

Hi lynnardm and Capt’n Ron, Nick from Sundance here. This is only my second post on the forum, and I'd like to thank you both for the wealth of info you've contributed to this resource (which I'm not affiliated with BTW).

There is an explanation for why we use batteries of the same type, and it is supported by the factory. As you know, when you're underway the battery charging source is the alternator on your engine as opposed to when you're plugged in the batteries are charged by your battery charger via shore power. Basically, the shore power battery charger is smart enough to charge batteries of different types, but your engine alternator is not. So we install batteries of the same type so that while you're underway and the engine is charging your batteries they are charged completely and evenly. I confirmed with the factory this morning that this is what they support.

Sounds like the batteries we installed in your boats are working for you, right? Let me know if that's not the case and I'd be happy to discuss. I'll send you both an email with my direct contact info.

[Capt’n Ron]

Nick, welcome to the forum and thanks for your response.

The concern is using a starting battery for house type loads will quickly damage a starting (the house) type battery. Everything I’ve read and talking to folks from Xantrex and Victron indicate the house battery should be type; deep cycle, AGM, or Lithium and not a starter. I have seen some suggest using two dual purpose batteries, but even though they are deep cycle they apparently don’t have the full efficiency of a true deep cycle battery. I understand the factory confirmed using two starting batteries is supported, but it doesnt appear to be aligned with industry recommendations or the best solution for owners. I know it can be done because I have 1 starting battery and a bank of 4 deep cycle batteries for the house and it works fine, so I would think this setup would work for a single house battery as well, but I could be missing something.

I am still learning about marine electrical so if you or others can provide additional clarification or insight I’m sure it would be appreciated by all!

Cheers,
Ron

[Cruising Cascadia]

Hi all.
I have a 2019 NC 895 offshore. I've been connected to shore power for about 3 weeks and came back to discover my starter battery is completely dead but my house bank is charged at 100%. I am able to start the engines with red bypass switch and slowly charge the starter with the engines running. Is this an alternator problem, bad battery charger or something else? I do have a marine electrician scheduled to come out in a few weeks but I would like to understand the problem if I can

Thanks in advance!
Stacey

[buff]

Hi folks.
I have a 2018 MF795 with two batteries. One starter and one house. They were both initially dual purpose AGM. The house battery was actually too small. The dealer installed only 70Ah. Since there was a fridge and heating running on it as well as the bow thruster I had to replace it now. Jeanneau actually states two 110Ah batteries.
So I decided to get a 105Ah AGM battery as the house battery and connected the bow thruster to the starter battery.
But the main thing I changed was to deactivate the Bluesea charging relay which isolates the batteries when the engine is not running. Instead I installed a B2B charger for the house battery. So now the house battery is always charged with 14.5V even when the starter battery is full and only taking 13.6V. The B2B charger has a maximum of 30A charging and it does that until the battery is almost full.
I can really recommend this solution since it charges the house battery with the correct charging pattern and with the optimum voltage. And of course it separates the batteries when the engine is not running.

Maybe that helps a bit.

Cheers
Buff

[westboating]

Feb 20, 2019 19:27:23 GMT Nick Buck-Niehaus said:

Feb 15, 2019 0:14:37 GMT Capt’n Ron said:

This may be obvious information to many, but not everyone may know this.  Your motor/starting battery and your house battery (or house bank) should be different battery types!  Your starter should be a good crank battery whereas the house battery should be deep cycle, AGM, or lithium.  

The reason I mention is because there have been some new boats delivered with crank batteries only for both starter and house. If this is the case, contact your dealer. 

I’d also recommend if you haven’t already done so, learn about your boat batteries, types, amp hours (Ah),voltage, charging system, discharge levels, inverter (if you have one or want one) AC and DC electrical, and what the Ah run is for each device. This will help ensure you do not find yourself stranded with dead batteries, or having to replace them too soon!  

I don’t claim to be a marine electrical expert, but what I’ve learned is an important aspect of happy boating. 

Cheers,
Ron

Hi lynnardm and Capt’n Ron , Nick from Sundance here. This is only my second post on the forum, and I'd like to thank you both for the wealth of info you've contributed to this resource (which I'm not affiliated with BTW).

There is an explanation for why we use batteries of the same type, and it is supported by the factory. As you know, when you're underway the battery charging source is the alternator on your engine as opposed to when you're plugged in the batteries are charged by your battery charger via shore power. Basically, the shore power battery charger is smart enough to charge batteries of different types, but your engine alternator is not. So we install batteries of the same type so that while you're underway and the engine is charging your batteries they are charged completely and evenly. I confirmed with the factory this morning that this is what they support.

Sounds like the batteries we installed in your boats are working for you, right? Let me know if that's not the case and I'd be happy to discuss. I'll send you both an email with my direct contact info.

[westboating]

Team,

     So more battery fun from the 895 (2019 model year delivered Oct 2018).  We spent the night on an un-powered dock.  We ran the fan (part of the diesel heater) and the fridge all night.  In the am the port motor started fine while the starboard would not.  We used the battery cross tie or shunt and it worked fine (thanks Jarod of Sundance Maintenance).  We had the issue again after a night on the hook and this time we were very power conscious running only the refrigerator.  We started the port motor and let her run for 30 minutes in an attempt to validate the charging process.  After the 30 min run the starboard would still not start.  The cross tie worked of course, but this behavior would lead me to believe the motors only charge their respective battery, port to crank battery and starboard to the house.  We validated this by running the starboard for 20 min, shutting it down and then successfully starting indicating the alternator is charging the house.  We could not of course verify if the starboard motor charges only the house battery, but we do know the port motor will not.  I wonder about the poor lonely thruster battery.

My take away is one, our boat may not be wired as Nick and the factory intended and two, we need more house battery.  My concern with a more substantial house battery is will the shore power battery charger have issue with dissimilar batteries.  That's my big question.

Thanks

[neverlander]

Boats mostly come with regular batteries for house, not any kind of deep cycle battery. E.g. Mine came with 110Ah house battery. Assuming fridge will use 5 Amps per hour, it will barely be enough for a night because this battery can be discharged to %60 or so. More importantly, battery life will be shortened quickly as you discharge to the limits.

I would calculate the current and near future power needs before changing the batteries. Deep cycle batteries are good for house one.

[vasko]

I'm using www.boat-vitals.com with alarms

[jgmallo]

Hello!

My Merry Fisher 895 with twin Yamaha F150 delivered in June 2020 have a setup of 2 x lead acid batteries of 140ah each, one for starting the port motor and the other to start the stardboard motor and house.

After checking the Yamaha's outboards owners manual it seems that Jeanneau is not following the installation recomendations, because as per manual they should have installed 3 batteries, 2 for starting the motors and then a 3rd one for housing, using a different positive cable running from the alternator to the house battery.

This should allow us to have a gel or lithium battery for housing with the possibility to be charged from the alternator without damage.

I will ask a Yamaha local dealer for advice.

[Capt’n Ron]

I agree, there should be at least 3 battery banks for 895’s and 1095’s and two for the 795’s; 1 for starboard engine (crank/start battery type), 1 for port engine (crank/start battery type), and 1 or more for the house (deep cycle battery type). In my opinion, any boat considered weekender or more will likely end up on the hook overnight and should have a dedicated house battery bank. As to how big the house bank should be will depend on your electronics and electrical needs.

Over the last 5 years of having my Jeanneau I’ve found there are wrong ways to configure batteries, there are a lot of ways that will work, but there is typically a best configuration for your boating needs.

Let’s start with the wrong:

• You shouldn’t use a deep cycle battery for your engines – The battery chemistry isn’t intended for this type of use and can lead to shorter lifecycle or battery damage.

• You shouldn’t use a start/crank battery for your house power – Same holds true for this configuration, the battery chemistry is not intended for many deep cycle uses and will result in shorter life or damage to the battery.

What can work:

• If you only have two battery banks, 1 for starboard engine, and 1 for port engine and house, at the very least you would want to have a dual purpose battery for the port/house battery and you may want to have the same for the starboard engine to ensure the charging profiles are the same (flooded or AGM).

What is best in my opinion:

• Three battery banks; 1 crank/start for starboard engine, 1 crank/start for port, and a deep cycle for the house. This does bring up the question regarding charging different battery types across the three banks. My understanding is as long as they are all of the same type; flooded or AGM, then the charging profile won’t be different. But if you have flooded batteries for the engines and AGM for your house you do end up with different charging profiles you will need to address. This can be solved by installing a DC to DC charging converter off one of the engine battery to the house bank. You will also need to address charging when connected to shore power and will likely need separate chargers for engine and house batteries as most chargers or have a charger than can charge multiple batteries with separate profiles (flooded or AGM).

FYI, I am not a marine electrician or claim to have a full understanding of marine electrical. I get my information from Pacific Yacht Systems videos, blogs and post created by Jeff Cote and his team who are marine electricians. I highly recommend you do your own research and configure your batteries to your understanding or that of a marine electrician.

Now as to why Jeanneau configures their boats the way the do, I really don’t have an answer. Like I mentioned, these boats are intended to be used for multiple days at a time and should have a dedicated house bank. My best guess is they do this to keep cost down and assume the dealer and the owner will determine what works best for their boating needs and configure it after factory. I actually agree with that approach as long as the dealer sales person ask you the right questions on your intended use during the purchase of the boat. In my case my sales person did and I ended up with a dedicated start/crank battery for my engine and a flooded deep cycle for my house along with an inverter/charger. I have since upgraded my batteries to AGM.

Here are a couple links you may find useful:

PYS One outboard to charge two batteries
PYS How to charge multiple batteries with one alternator

Again, this is just my opinion and I welcome others input, but hope it helps  More knowledge about your boat is always a good thing!

Cheers,
Ron

[zaphod]

The difference between cranking batteries and deep cycle is not chemistry. They are both lead acid chemistry. The difference is in the cell structure. Cranking batteries tend to have thinner plates and are more suited to putting out high amps for short periods, whereas the thicker plates in the deep cycle batteries are more suited to putting out lower amps over a longer period of time and enduring deeper discharges.

An appropriately sized deep cycle battery is more than capable of starting an engine, but I wouldn't want to use a cranking battery in my house bank.

It does seem bizarre that Jeanneau would use one of the engine batteries for house loads. It is ridiculous to think that after a night on the hook with the fridge on you would not be able to start one engine!

If it were my boat I would change that right away! If you plan to use the fridge for more than a day you would also do well to upgrade the house bank as well. 1 battery, even a 140ah battery will not cut it for anything more than overnight. A standard lead acid battery can only be discharged to 50% so you would only have 70ah to work with. My fridge burns 40-50ah just from dusk to dawn alone.

I have a sailboat so I am not totally familiar with the systems on the powerboats. How many amps do the outboard alternators put out?

[jgmallo]

Sept 2, 2021 0:57:56 GMT zaphod said:

The difference between cranking batteries and deep cycle is not chemistry. They are both lead acid chemistry. The difference is in the cell structure. Cranking batteries tend to have thinner plates and are more suited to putting out high amps for short periods, whereas the thicker plates in the deep cycle batteries are more suited to putting out lower amps over a longer period of time and enduring deeper discharges.

An appropriately sized deep cycle battery is more than capable of starting an engine, but I wouldn't want to use a cranking battery in my house bank.

It does seem bizarre that Jeanneau would use one of the engine batteries for house loads. It is ridiculous to think that after a night on the hook with the fridge on you would not be able to start one engine!

If it were my boat I would change that right away! If you plan to use the fridge for more than a day you would also do well to upgrade the house bank as well. 1 battery, even a 140ah battery will not cut it for anything more than overnight. A standard lead acid battery can only be discharged to 50% so you would only have 70ah to work with. My fridge burns 40-50ah just from dusk to dawn alone.

I have a sailboat so I am not totally familiar with the systems on the powerboats. How many amps do the outboard alternators put out?

Hello Zaphod,


According with the Yamaha's technical specifications, 50A is maximum amps of the outboard alternator for charging.

Regards!

[westboating]

Follow up to follow up:

Now we have a problem with the start/port motor battery.  I now know the start battery starts and is charged by the port motor.  Unless the buses are connected via the switch only the port alternator charges the port battery.  The starboard motor is started by and charges the 'house' battery.  Both of my batteries are labeled 'Extreme Deep Cycle'. 

The problem I now have is the start battery will not start the motor but will run other things like trim and gauges.  With both batteries having charging limitations, I'm left to suspect they are both suffering from either age or lack of water.  I'm going to try to see if adding water improves performance. 

We've had this boat since new.  We took delivery in October 2018.  So, these batteries shouldn't be more than 3ish years old, which is a bit too young to be killing batteries. 

Fun stuff....

[westboating]

Today I went and looked at the batteries closer.  Does anyone have 3 (4 including the thruster battery)?  I think that is the intended configuration, but our has 2 in the back, one in the front.  Our house bank consists of one 'extreme deep cycle' battery.  Upon closer inspection the batteries aren't sealed, but rater the label is designed to come off for inspection and maintenance.  When I opened the cells, they were very low on water to dry.

I watered one battery and had to get more distilled water.  So as this thread is titled, check your batteries.  I need to go back and water the house battery and check the thruster battery.  A dry battery would explain the good voltage with the inability to provide sufficient cranking current.

[Capt’n Ron]

Here is a link to a good seminar on batteries.  It's a bit long, but has a lot of good information that has been discussed on this forum.


PYS all about marine battery video

[rxc]

"Today I went and looked at the batteries closer. Does anyone have 3 (4 including the thruster battery)"

I have a 43DS sailboat, with 7 batteries. 4 golf carts as my house battery, one Group 31 main engine starting battery, one identical Group 31 up forward for the windlass and the bow thruster, and one Group 24 to start the genset. I have two battery combiners to charge the house battery, the engine start battery, and the bow thruster at the same time when the engine is running and the charging voltage is over 13.2(I think) volts. I haven't switched to LiFePO4 batteries because I don't want to have to deal with Battery Management systems and mixed chemistries. I replace the golf carts every 5-6 years, and the engine and bow thruster batteries approximately every 4 years (they are sealed units).

There is a LOT of discussion about batteries here. The sailors try to run their engines as little as possible, and are the best source for info. It is not quite q religious issue, but there are a lot of strong opinions, so read as much as you can, evaluate your need for power, do the calculations, and check your banking account balance. If you are handy and want to really know how your boat works, re-doing the electric system yourself will be a good education.

Have fun and don't hesitate to ask questions.

[zaphod]

Sept 7, 2021 23:25:23 GMT westboating said:

Today I went and looked at the batteries closer.  Does anyone have 3 (4 including the thruster battery)?  I think that is the intended configuration, but our has 2 in the back, one in the front.  Our house bank consists of one 'extreme deep cycle' battery.  Upon closer inspection the batteries aren't sealed, but rater the label is designed to come off for inspection and maintenance.  When I opened the cells, they were very low on water to dry.

I watered one battery and had to get more distilled water.  So as this thread is titled, check your batteries.  I need to go back and water the house battery and check the thruster battery.  A dry battery would explain the good voltage with the inability to provide sufficient cranking current.

If your batteries were that low on electrolyte, then they are almost certainly damaged. You will recover some of their capacity by topping them up, but they will never be the same as new.

Here's where we get into battery types. Flooded lead acid batteries have one advantage; they are cheap! Their disadvantage is that they require regular maintenance, and are prone to leaking, hence they need to be stored upright and in a liquid tight box.

AGMs, on the other hand, are more expensive, but they are sealed and require no maintenance. They can be stored in any position and do not need a battery box because they don't leak.

Both batteries need to be treated well and not discharged below 50% capacity in order to have a long life. (Unless they are Firefly Carbon Foam AGMs, which can be discharged below 30% without damaging them,)