Twin 40s battery question

P

Pandion

New member
Folks, I recently happened upon an old discussion (http://www.c-brats.com/viewtopic.php?t=59&sid=95bde120bbb205b4ca4584d273f6730c) of battery wiring for twin Honda 40s, and now have a better understanding of why the charging coil in my starboard engine got fried (once for the boat's previous owner, once for me).

Aparently, each engine needs to be wired separately to its own battery, and having both engines' charging systems connected to the battery switch (a configuration the factory may have used for a while) can cause damage to the charging coils.

Oops. I will rewire the system as advised.

Can anyone tell me what the correct battery size is for a Honda 40? I can't find that info in my owner's manual.

Thanks.
 
Andy,

We aren't home to look at what we have.

I know each is directly wired to one battery. Each battery has a switch in the cockpit. We do not have a "house" battery.

I'm making a very short jumper cable to be able to connect the positive terminals if I need to "jump start" one of the motors. By starting the motor with the "low" battery, I can then remove the jumper cable and then start the motor with the "good" battery.

This link shows, in the section titled "New way" how to obtain the same results with a 1, 2, both, off selector switch.

http://continuouswave.com/whaler/refere ... ttery.html

I'm too lazy to remove the current switches and rewire a new one.
 
Generally what is "said" 13 years ago is still true.
1. each engine should be wired so it goes to its own battery.
2. never run the engine with both outboard engines feeding one battery
3. Never run an engine so that the charger is not attached to any battery.

A lot of other things have changed. There is now the "center fielder" by Balmar, which allows two engines to run into a battery bank, but this is made for alternator engines, which use the specific Balmar regulators.

AGM batteries have come along, and they will take a lot more charging power.

There are some things I disagree with--and part has to do with boat usage and way things are set up.

"A charger is not necessary" Yes, if the boat is run at least once a week--or daily--as commercial boats. And, there is no heavy house load.

Nowdays, we see more boats with refrigeration, with heavy house loads, more electronics, etc--and there is a need to fully top off house batteries===and if the engine is not run enough, to top off start batteries.

I happen to use 3 group 31's on my 22--why? I use a combiner, I have heavy house and electronic loads, and don't run my boat every week. I want low self discharge, but also ability to charge fast, and discharge fast, if necessary...

For the average 22, with twin 40's--a set of group 24's lead acid batteries is the way the boat should be rigged, with one battery to each engine. If you are going to be using a lot of house load, then you can look at ways to add a 3rd battery, but for most of us, not necessary.
 
Thanks folks. Would you go with dual purpose or starting batteries? And what might recommend one brand of battery over another?
 
In planning the electrical set up for my 2014 CD 26 Venture with twin Honda 90s,
I've gone thru the learning curve to now know twin outboard engines each
require their own starting battery. Before getting to this point, I wanted one
12V starting battery for the engines and two paralleled 12V batteries for the
house. Then the Honda rep said "Nope, you need 2 starting batteries if you
have twin engines" but never explained why in this day and age.

So I end up with 2 Group 24 flooded lead acid (Interstate) marine cranking
batteries, one for each engine, and 1 Group 27 flooded lead acid deep cycle
marine battery for house needs. I want to switch the Gr 27 to a Gr 31 but don't
know if there is space. I mind their recharging needs and they have worked well
to date. Could have spent more $$$ on AGMs but why?

My manual for a single BF90 Honda minimum requirement for a starting battery is
"12V-55Ah/5HR  (65Ah/20HR) (CCA582A)".

A quick search for a single Honda BF40, the manual say only "12V - 70AH".

Aye.
 
Maybe Yamaha is different to Honda. I have never owned a Honda outboard so I really don't know. When we took delivery of our 2008 Venture 23 with twin 60 hp Yamahas I was surprised to find only one battery switch. In addition, the boat was equipped with one starting battery and one deep cycle battery, both group 27.

It was explained to me that by using an ACR both batteries would be charged as necessary when running but that only the deep cycle battery would be used for "house" purposes, ensuring the starting battery available for the motors at all times. The battery switch was [is] simple with positions off/on/combined. This last position obviously brought both batteries together if necessary to crank a motor. Once one motor is running, of course, the output from that one can help start the second. Both motors are wired to charge the one system. The layout can be seen here https://www.bluesea.com/support/referen ... plications if you look for 2 motors/2 batteries. On shore power the guest battery charger is wired for two banks, monitoring and charging each as necessary.

Coming from an age where I was told that each motor needs its own battery and should only charge that battery [a view that still seems to be common in the marketplace] I was skeptical. I bought an emergency jumpstart battery and have kept it in a locker under the V berth since, taking care to bring it into the open air for periodic charging. I have never used it.

Coming from the Chesapeake Bay where hot summer temperatures and perhaps not the greatest battery charger meant that I was replacing batteries every 2 to 3 years I wondered how this "new technology" would affect battery life. Each year for six years I hauled the batteries out of the boat and down to the Interstate warehouse for load testing. They don't sell batteries retail but were happy to do the test since I had Interstate batteries. Each year both batteries reached spec for new status. I knew this couldn't go on forever and I didn't want to pay for two new batteries at the same time but I again came from an age where you didn't mix old with new. Educated by the Interstate expert I now know that this is quite possible using the circuitry with an ACR. Last year I subsequently bought a new group 29 deep cycle Interstate battery to use for "house" and moved the original deep cycle group 27 to the starting position. Obviously the wiring needed a change. Both batteries fitted perfectly since the group 29 is only slightly larger than the 27.

A photo showing the whole setup is in the Chimo album showing the boat in October 2016.

Sorry for rambling on but hopefully this is of interest to someone.
 
chimoii, I have twin yami 40's on my 22 and have the same Blue sea systems ACR system you have. I installed myself and followed the Blue sea systems instructions and wiring diagram which does have a battery for starting and a house battery obviously wired through the switch. So yes both motors are wired to the dedicated "starting" battery and I have not had any issues for 2 years......should this be of concern?

Also a note, I've always been under the impression that with a system like this you want both batteries to be the same type and age so they charge evenly, I understand why you chose the different style batteries but you may want to consider getting a duplicate to the starting. I chose to get 2 dual purpose baterries and I"ve had good results. Maybe someone else will chime in on that concept.
 
Agree that both batteries should have the same age, size, type and characteristics.

As long as the battery has adequate MCA (Marine Cranking amps ) or CCA (Cold Cranking amps) as what the engine manufacture requires, then a dual purpose battery is fine.

For some time folks were not using AGM batteries with Yamaha engines. For some reason the engineers at Yamaha didn't think that AGM batteries met their criteria. I know lots of folks (including myself-at one point) who used AGM with Yamaha, and had no problems.

I have a single Honda, and use Group 31 AGM--the Group 31 because I need the amp hours and the ability to rapid charge because of the refer/freezer. (I charge at C/3 (1/3 capacity) example: My batteries are rated for 110 amp hours. I charge at a little over 30 amps--monitoring the temperature of the battery)
 
CDory23":2ve746jo said:
chimoii, I have twin yami 40's on my 22 and have the same Blue sea systems ACR system you have. I installed myself and followed the Blue sea systems instructions and wiring diagram which does have a battery for starting and a house battery obviously wired through the switch. So yes both motors are wired to the dedicated "starting" battery and I have not had any issues for 2 years......should this be of concern?

Also a note, I've always been under the impression that with a system like this you want both batteries to be the same type and age so they charge evenly, I understand why you chose the different style batteries but you may want to consider getting a duplicate to the starting. I chose to get 2 dual purpose baterries and I"ve had good results. Maybe someone else will chime in on that concept.
Click to expand...

No, you shouldn't have any concern. You have a great setup. To answer your other point, one certainly shouldn't mix types, for example AGM with lead/acid. Your setup with a starting/deep cycle is fine. Mine with one 27 and one 29 is also fine. Going deep cycle for both just gave me a little higher CCA compared to a starting battery. The ACR looks at the state of each battery and charges accordingly. In the past with one charger simultaneously charging two different size batteries this would have been a potential problem.

As technology changes there are lots of opinions expressed on the internet, including mine, that may not be current or applicable to a specific situation. As I mentioned, I don't know Honda motors. When I went through this exercise I contacted Blue Seas through their webpage. I very quickly was connected by email with the factory rep for the area who was very informative and clear. I would suggest anyone who has questions to do something similar.
 
chimoii":dmsydk9c said:
.....
No, you shouldn't have any concern. You have a great setup. To answer your other point, one certainly shouldn't mix types, for example AGM with lead/acid. Your setup with a starting/deep cycle is fine. Mine with one 27 and one 29 is also fine. Going deep cycle for both just gave me a little higher CCA compared to a starting battery. The ACR looks at the state of each battery and charges accordingly. In the past with one charger simultaneously charging two different size batteries this would have been a potential problem.

........
Click to expand...

Is the underlined really true? Perhaps I have missed something in the Blue Seas ACR?

Also "going deep cycle " does not necessarily give you more CCA. The starting battery and deep cycle battery differ by the construction of the plates. Some deep cycle batteries may have less CCA.

Here are quotes from the web site about ACR:

What is an ACR?
An ACR parallels (combines) batteries during charging, and isolates them when charging has stopped and after battery voltage has fallen. An ACR is intended to keep a load from discharging both of the batteries.

How does an ACR work?
An ACR senses when the voltage of either of the batteries rises to a level indicating that a charge source is active (13.0V for 2 minutes). The ACR′s contacts then connect and the ACR applies the charge to both batteries. If the voltage on both of the batteries subsequently drops to 12.75V for 30 seconds, the ACR will disconnect, isolating the batteries.
.....

Will an ACR manage the charge of my individual battery banks?
An ACR does not direct the charge to the battery that “needs it the most” or has the lowest terminal voltage. If there is a charge present on either battery, indicated by a high enough voltage, the ACR will combine the batteries.
Click to expand...

There may be some ACR or other devices which sense the actual charge in the battery (Some expensive battery chargers have this capability). But it is my understanding that the Blue Seas ACR (which I use) are only sensing transfer switches, and do not proportion the amount of charge.

It can be debated if group 27 and group 29's should be combined. For the most part it does not seem to do any harm. (remember that "group" are only case sizes; not capacities.) Capacity is expressed in Reserve capacity or Amp hour capacity.
 
During the 16 year life of our twin Honda 40 hp powered boat, it started out with group 24 flooded lead acid dual purpose marine batteries, then due to the tight confinement of them in the starboard lazaret, making acid level checking difficult, I switched to Cabalas, group 24, AGM dual purpose marine. We are now on the 2nd set of these. None of the batteries I've replaced have gone bad before replacing, but thinking it prudent to lower the chances of that happening in some remote location by replacing after 5 or 6 years with them still good.

Our wiring set up is simple with each battery dedicated to a single motor, but with a 1, 2, combine or off selector switch to allow for combining to start the Wallas or if one battery does go bad. I alternate between them for house battery use. We do a majority of our cruising on one motor at displacement speed & for the most part will during that time have the switch set to the house for the battery being charged. In the past I have twice had a charge coil burn out. Both times, it was caused by having the batteries combined, while running both motors in conditions, where I was having to do excessive throttle adjustment for an extended period of time. I now no longer combine them when both motors are running, but in the past, when I did, it was for many years under extended cruising conditions & the charge coil only went out, when the conditions were causing unbalanced charging between the motors to an extreme point. After this happened to us on an extended Alaska cruise in 2007, I talked to Les at EQ & he explained to me why it happened.

Battery chargers were recently discussed on another thread, but being as they do effect batteries, I'll comment about chargers here. I readily accept there are better onboard chargers than Guest & many would be better off switching to one of them, but in our case & maybe some others like us, where amp draw is fairly low, when hooked to shore power at the dock, on the go or at anchorage, the cheaper Guest is more than adequate. For us the original Guest 2610, 10 amp charger is still doing fine after 16 years of service. During these years, It has been used here at home during the off season, at the dock in Yellowstone, at many different marinas in SE Alaska & extensively while cruising & powered up by our Honda 2000 generator without any damage to our batteries.

Jay
 
You are absolutely correct Thataway. Instead of 'each battery' I should have said 'both batteries'. Your quote para. 2 "How does an ACR work?" says it even better.
 
Pandion":3vluqdep said:
Jay, when you're using your charger, do you hook it up to one battery and put the switch on "both?"
Click to expand...
I have never hooked the generator directly to the batteries, instead the generator's 120v plug outlet is connected to the input of the shore power connector & thus the Guest 2610 does the actual charging at a total rate of 10 amps of which 5 amps goes to each battery. I do put the battery switch to the combine position, while doing this just like I normally do when using shore power at a dock. Except in this case it's more like being connected to the 15 amps at home instead of the 30 amps normally at a dock. I trust the Guest regulated charge more than the direct generator output even though I do lose a few amps charge, while the onboard charger is in its first stage. The Guest 2610 is a automatic dual battery, three stage charger that drops the amp battery input to 0.1 amp or less, when the batteries are charged & in the stage three float cycle.

I've always used the combined switch setting, when charging the batteries with the onboard charger & through all these years it's worked out well, but after reading the manual tonight I'm now wondering if that's best. The Guest 2610 is connected to the two batteries independently & the manual says the charger will direct the most charge to the lowest charged battery first. By combining them it seems to me this would be disrupted. When the battery switch is turned to the one or two position it's then directing which battery will be used for the house, leaving the charger to charge them independently, but when combined both batteries are going to the house, but it seems the charger would look at the batteries, then as one battery & not allow the charger to charge as designed. I'm thinking now that the combination position of the switch should not be used when battery charging on shore power or when the batteries are being charged with both motors running. Is this correct or have I been doing it right all along.

Jay
 
Andy, I saw you asked about "Dual purpose" vs a normal start battery. Don't think I found you got an answer so I'll tell you where I am with that. As you know I run twin 40 Yamis and I have 2 group 29 Interstate batteries. Each battery is wired to charge off its own engine, and I have a 1,2,Both and Off switch.

My mechanic has recommended using Deep cycle type batteries for both sides. I have been running them for 10 years now, going on 4 years for the second set. Last fall (2015) I put a pair of BatteryMinder chargers on, one for each side. When I store the boat, I plug those in directly wired for each battery, and they charge intelegently, and sulphate when needed.

The Deep Cycle has plenty of start power and also functions well for me as house battery system.

Hope that helps,

Harvey
SleepyC :moon
 
Thanks Harvey. There is no power in the yard where I keep my boat, at the Everett Marina, so in the off season I have been driving up there every week or two, and moving it to a location where I can plug in my portable charger. I am thinking I need to look into solar panels and trickle chargers, (and I know there is a wealth of info on that subject, on this site).

Are any of you Pacific Northwesterners successfully using solar in our wet winter climate?
 
I use two group 24 starting batteries... and my boat always sits lower in the water on the battery side..... I always assumed it was that all the weight was on that side....I usually don't carry more than 8 to 10 gallons of water in the tank.... so if all you'all have the same setup what is making my boat sit lopsided ???
 
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