Adding a battery

[Zzmeyer]

I have a new Jeanneau 349 with three Exide ER350 80 amp low maintenance dual flooded batteries. One starter and two house. Due to physical constraints and difficulty of getting the Exide I was thinking of making all three Exide the house bank and adding a simple flood start battery. They are on separate circuits, but with a combiner. Are there any issues with doing this. Thanks!!

[Uncle Bob]

Originally Posted by Zzmeyer

I have a new Jeanneau 349 with three Exide ER350 80 amp low maintenance dual flooded batteries. One starter and two house. Due to physical constraints and difficulty of getting the Exide I was thinking of making all three Exide the house bank and adding a simple flood start battery. They are on separate circuits, but with a combiner. Are there any issues with doing this. Thanks!!

Makes perfect sense to me.

[GILow]

Originally Posted by Zzmeyer

I have a new Jeanneau 349 with three Exide ER350 80 amp low maintenance dual flooded batteries. One starter and two house. Due to physical constraints and difficulty of getting the Exide I was thinking of making all three Exide the house bank and adding a simple flood start battery. They are on separate circuits, but with a combiner. Are there any issues with doing this. Thanks!!

Sounds ok, my main concern would be whether the batteries are in significantly different condition due to age or treatment. The two house batteries have probably lived a very different life to the engine battery.

If the boat is NEW, as against new to you they should be fine. But then I imagine there would be warranty concerns if you chamge things.

EDIT: And, of course, you'd need to make sure the wiring was adequate to prevent voltage imbalance across the combined.bank.

[Zzmeyer]

Originally Posted by GILow

Sounds ok, my main concern would be whether the batteries are in significantly different condition due to age or treatment. The two house batteries have probably lived a very different life to the engine battery.

If the boat is NEW, as against new to you they should be fine. But then I imagine there would be warranty concerns if you chamge things.

EDIT: And, of course, you'd need to make sure the wiring was adequate to prevent voltage imbalance across the combined.bank.

Thanks for that input. Yes. The boat is new, new, not just new to me so all the batteries should be about the same age and the house bank has been used only for a couple weeks, mostly at the dock. I was thinking of converting the current engine battery to the third house bank rather than adding a third house bank 1) because I can't get the same exact battery I'm hoping whatever difference between a new engine battery and the house batteries won't affect much as they are on separate circuits and should only interact when the combiner kicks in and 2) the three current batteries are all right next to each other so there is no wiring length difference. The new engine battery will only be about a foot further. You mentioned warranty and I'm sure if there is a problem they will have an excellent case to deny me.

[alaskanviking]

Electrically it won't take much. This will add to your house bank capacity. bigger house bank has a lot of advantages. Just need cables to put in series with the other two batteries.

If the new starter battery location is only a foot away than the wiring won't move much.

Battery chemistry has to be the same. Voltage has to be the same. Is the house bank 12v? If it's 24v your plan won't work.

Kind of a small bank though.

[Phyrcooler]

I’m in a similar boat (pun intended). I’m assessing adding a starter battery under the companionway in my Beneteau 38.1 and putting a deep cycle in the location of the current starter battery. They only provided Group 24 sized batteries (and space for same) - so it doesn’t look like I can upgrade the battery size. SO... by relocating the starter battery, this will allow me one additional, for a total of 4 house batteries. One of many projects I am analyzing for need and priority!

[Uncle Bob]

Originally Posted by alaskanviking

Electrically it won't take much. This will add to your house bank capacity. bigger house bank has a lot of advantages. Just need cables to put in series with the other two batteries.

If the new starter battery location is only a foot away than the wiring won't move much.

Battery chemistry has to be the same. Voltage has to be the same. Is the house bank 12v? If it's 24v your plan won't work.

Kind of a small bank though.

Just a word of caution, the third battery goes in parallel with the other two, not series.

[Zzmeyer]

Originally Posted by alaskanviking

Electrically it won't take much. This will add to your house bank capacity. bigger house bank has a lot of advantages. Just need cables to put in series with the other two batteries.

If the new starter battery location is only a foot away than the wiring won't move much.

Battery chemistry has to be the same. Voltage has to be the same. Is the house bank 12v? If it's 24v your plan won't work.

Kind of a small bank though.

Yes 12 volts. Agree it is a small bank even with the addition. The standard house bank is one 80 ah battery.

[GILow]

Originally Posted by Uncle Bob

Just a word of caution, the third battery goes in parallel with the other two, not series.

Spoilsport, I was looking forward to the fireworks.

[GILow]

Originally Posted by Zzmeyer

Thanks for that input. Yes. The boat is new, new, not just new to me so all the batteries should be about the same age and the house bank has been used only for a couple weeks, mostly at the dock. I was thinking of converting the current engine battery to the third house bank rather than adding a third house bank 1) because I can't get the same exact battery I'm hoping whatever difference between a new engine battery and the house batteries won't affect much as they are on separate circuits and should only interact when the combiner kicks in and 2) the three current batteries are all right next to each other so there is no wiring length difference. The new engine battery will only be about a foot further. You mentioned warranty and I'm sure if there is a problem they will have an excellent case to deny me.

Well, it all sounds pretty sensible to me. (Uncle Bob’s advice included.)

My 40 year old boat didn’t come with a warranty so I never got to test their reasonableness.

I am a little surprised by how small they make their standard house bank though. I bet there was an optional upgrade to the house battery capacity that is supplied at a horrendous markup.

I worked with some management guys from one of the Australian car manufacturers a LONG time ago, and they assured me that the base model was actually sold at a slight loss (they make their money on those on the service and the brand recognition) but the real profits were made on all the optional extras on the upgraded models. They seemed pretty genuine about that.

[alaskanviking]

Originally Posted by Uncle Bob

Just a word of caution, the third battery goes in parallel with the other two, not series.

Yep, good catch, thank you. I meant parallel

[Zzmeyer]

Originally Posted by GILow

Well, it all sounds pretty sensible to me. (Uncle Bob’s advice included.)


I am a little surprised by how small they make their standard house bank though. I bet there was an optional upgrade to the house battery capacity that is supplied at a horrendous markup.

.

I asked the dealer about what he considered Jeanneau flaws (I've had 2, both new). I always felt they had small fuel tanks, but for a 33 foot boat 34 gallons is a lot for me. He said house battery capacity. The 2, 80AH house batteries ARE an upgrade. Standard is 1. I think AGM was an option, but I bought the boat late in the manufacturing process so wasn't an option for me. I really want more than 3 house, but I don't easily have the real estate. I guess I shouldn't complain. My first boat, a Pearson 31, had only one battery period.

[GILow]

Originally Posted by Zzmeyer

I asked the dealer about what he considered Jeanneau flaws (I've had 2, both new). I always felt they had small fuel tanks, but for a 33 foot boat 34 gallons is a lot for me. He said house battery capacity. The 2, 80AH house batteries ARE an upgrade. Standard is 1. I think AGM was an option, but I bought the boat late in the manufacturing process so wasn't an option for me. I really want more than 3 house, but I don't easily have the real estate. I guess I shouldn't complain. My first boat, a Pearson 31, had only one battery period.

Wow, yes, that's a little small.

But on the upside, it keeps you thinking about efficiency. I've had a number of conversations these last few weeks with people who have struggled to charge their house banks. I've often felt they would have been better off reducing their consumption instead. But they've put huge banks in, sometimes lithium, and done nothing to address the real problem which is they treat the boat like a house on mains power.

Perhaps your restriction is a blessing in disguise.

[Zzmeyer]

Originally Posted by GILow

Wow, yes, that's a little small.

But on the upside, it keeps you thinking about efficiency. I've had a number of conversations these last few weeks with people who have struggled to charge their house banks. I've often felt they would have been better off reducing their consumption instead. But they've put huge banks in, sometimes lithium, and done nothing to address the real problem which is they treat the boat like a house on mains power.

Perhaps your restriction is a blessing in disguise.

You are so right. I had a Fountain Pajot 47 that used 35 amps every hour, day and night. Two fridges and a freezer, two inverters that each used 24 amps per day on standby, electric toilets. I had a 13.5kw generator to power my 5 air conditioners. Most of my fellow owners had 2,000 watts of solar and over 1,000 watts of Lithium. I'm installing a Victron BMV712 to track usage. Fridge will be my biggest user and hoping to stay below 100 amps a day (not underway).