Dual Batteries

[Okie Boarder]

I'm planning on reinstalling both batteries like I had last year. The way I did it last year was the "house" battery was only connected to the stereo and amp and it wasn't connected to the engine. I threw it on the battery charger at home. This year I'd like them both to be able to be charged by the engine. Here's my set up:

Starter Battery:

Marine Starting (24 Series)
625 CA
500 CCA

"House" Battery":

Dual Purpose (Starting / Deep Cycle)
875 CA
205 Reserve Capacity

**Goal**

Engine always charges batteries individually when the engine is running with priority to the starting battery. When engine is off the drain is always on the "house" battery, or never drains the starting battery below a certain level.

I've started reading about battery switches, relays, voltage sensing switches and voltage sensing relays. It kind of sounds like I should use a switch and VSR, but I'm not sure.

Can anyone provide some feedback or share your setup?

[tg0824SSVGG]

Okie,

On my previous boat, I had a system setup using an isolator, I chose the "Hellroaring (http://hellroaring.com/)" one.

It is SUPPOSED to isolate your batteries electronically - so they can both be
charged, but used independently. The one I used has a switch I installed under
the dashboard that would allow me to "combine" the batteries if I needed it -

Take a look - I am not sure it was the BEST setup, but it seemed to meet my needs
at the time.

In the Supra, I have an onboard charging system that gets plugged in at home -- but
I don't drive my stereo like some on here do.

[jonyb]

A Perko or other type switch like Todd recommended is ideal to select which battery is opened to the alternator.

[michael hunter]

Okie
All you need is a battery Isolator. Since you are using the batteries for two separate operations the isolator will connect them to the alternator only when the alternator is charging. When the engine is off the batteries are totally separate. You can run the stereo
until it's dead and still have a full charge for starting.
Check out donrowe.com the 95 or 120 amp units should be fine depending on your alternator size. They are super easy to wire up and only cost $39-57. Best of all the system is totally automatic no switches no maintenance.

[docdrs]

here is a thread in the moomba forum with everything ya want to know

http://moomba.com/msgboard/showthread.php?t=10260

plus there is a pic in my profie that shows the bep vsr dual battery set up

[Newty]

Surepower 1314 for sure!
I had an isolator and it worked well but was unable to ever get a complete charge. There is more than one volt loss through an isolator. One volt may not seem like much but when you only have a 13-14 volt capacity max and you loosing 1 through an isolator that adds up.
Perko switches work too but you always have to stop and think about which battery is on and being used etc.
The sure power only requires a simple jumper from your starting battery to the unit and a jumper from the unit to your aux battery.
It will always try to maintain a 13.2 volt charge on your starting battery.
If your starting battery drops below 13.2 it disconnects the batteries. When your alternator charges your starting battery beyond 13.2 the combiner connects your batteries together and keeps them together until your starting battery drops below setpoint, typically once the motor is turned off. Hence your starting battery will never go dead due to your stereo and your alternator will charge it automatically once started.
The best part is it can be had for less than $60.
http://surepower.com/pdf/separatorinterconnect.pdf
Let me know if you have any q's.
I dont work for, or sell surepower equip but I've have always had very good luck with the stuff.

[docdrs]

Newty's is just like the blue sea and the bep marine vsr's
here is the install page
http://www.fourwheelcampers.com/batteryseparator1315.pdf

the 1314 is single senseing the 1315 is dual sensing so you can home charge your aux battery with a charger maintainer first then it will maintain both after its fully charged

[Okie Boarder]

Thanks guys. I'm liking the Blue Sea (http://bluesea.com/category/2/productline/overview/329) setup. I'm leaning towards going with that. I like the fact I can combine batteries. I also like the "Off" switch.

[87SunSportMikeyD]

The BlueSea is much more expensive than the SurePower, and the perko switch is totally unnessecary when you have the SurePower. The SurePower is a more advanced unit and actually costs less, about $65 after wakeworld discount through brettyates/polarbill. Surepower automatically combines or seperates batteries based upon power consumption, state of battery, which one needs charge, etc.

Are you going to upgrade alt too? Check dbalternator.com for nice american made alt for $80.

[TayTay]

So one thing, kind of off on a tangent here, but it has to do with dual batteries and switches. I have just a Perko switch for my batteries. Settings are 1; both; 2; off. Now I was told that its good to turn it off when you are not using the boat because it is better for the battery. Well whenever I turn it off, my dang stereo loses all of its settings. Do I have it all wired wrong, or is that supposed to happen?

[Okie Boarder]

Hmmm, I'm going to keep looking into this. Maybe I don't need the switch. I do like the idea of the switch for the "combine" idea, with respect to the Blue Sea option.

Tay,

Yeah, you remove power completely when you go to off. You could wire the stereo 12V constant wire directly to the battery. But, then you defeat the purpose of the switch being put in the "Off" position because the stereo is going to drain the battery slowly.

[cmtaylor777]

Tay Tay

I have the same issue and I don't think there is a way around it. You are shutting down all power to the stereo head unit. This resets the "brain". When you turn the battery back on all presets are cleared. Much like reinstalling the unit. Some newer high end units will save the settings on an internal hard drive but I'm guessing you have a standard head unit. My Kenwood 7120 in my truck will do this, but my older kenwood that is in my boat does not save anything.

I HAVE THE SAME SET UP AND IT IS VERY ANNOYING! If anyone has a way of fixing this, I would love to hear it.

P.S. Tay Tay

I am in the process of changing my amp rack to something like yours. Did you ever finish it? I spent the whole weekend on it and I am almost finished. I incorporated the Perko switch and fuses on the rack. Needless to say it has been a tedious process. I will post the pics when I finish.

[dusty2221]

Can't wait to see the pics!!

[tg0824SSVGG]

in the setup I was describing, this is a TOGGLE switch at the dash, not a switch
like a Perko ...

http://hellroaring.com/images/remote.jpg

Here is the isolator:

http://hellroaring.com/images/BIC%20Installed.jpg

[87SunSportMikeyD]

Oakie and Tay - I dont want to sound like a knowitall because I'm no pro, but it is my understanding that the SurePower accomplishes what both of you are looking for.

Oakie, the SurePower will AUTOMATICALLY combine batteries for starting if the main batt is too low, or when charging if it detects one batt is lower than the other it combines or just charges one automatically. But it also automatically keeps you from leaving batteries combines and draining both like is possible with Perko.

Tay, with the Perko you are physically disconnection power frpm one batt or the other. This is going to reset your stereo everytime. The SurePower will keep your stereo battery isolated but always connected. Even if there is a powerdrain while you are away, just the stereo battery will be dead and once you start driving the alt should charge it (I think it could bring it back from the dead...right?). Especially if you had a nice new 105amp alt!

[Okie Boarder]

Hmmm, I'm going to read more about the Surepower too.

I have a concern with combining batteries for charging. I would think only one battery at a time should charge or else it puts too much load on the alternator, right?

[TayTay]

Tay Tay

I have the same issue and I don't think there is a way around it. You are shutting down all power to the stereo head unit. This resets the "brain". When you turn the battery back on all presets are cleared. Much like reinstalling the unit. Some newer high end units will save the settings on an internal hard drive but I'm guessing you have a standard head unit. My Kenwood 7120 in my truck will do this, but my older kenwood that is in my boat does not save anything.

I HAVE THE SAME SET UP AND IT IS VERY ANNOYING! If anyone has a way of fixing this, I would love to hear it.

P.S. Tay Tay

I am in the process of changing my amp rack to something like yours. Did you ever finish it? I spent the whole weekend on it and I am almost finished. I incorporated the Perko switch and fuses on the rack. Needless to say it has been a tedious process. I will post the pics when I finish.

I haven't finished it yet. I work full time and am taking 21 credits of college right now so I have NO time to do anything. Hopefully this weekend I can make some more progress. The rack is done, now I just have to organize and clean it all up.

On the thread topic, I do have a new deck specificaly made for boats from Alpine. It is there "digital media player". Honestly, I dont listen to the radio but what I "lose" is the settings for the subwoofer and the internal crossovers and the fade/balance. I think what would alleviate that would be a WS-420 ;) We will see this spring but I may just have to buy one!

[87SunSportMikeyD]

The SurePower moderates how strong the incoming charge demand is so as not to over-load the Alt. :)

[Newty]

The surepower WILL NOT combine batteries until the starting battery is charged past 13.2 volts while the motor is running or when you have a charger on the starting battery. Once the starting battery is charged past 13.2v it will then combine the batteries until the starting battery drops below 13.2v again. It will only do that if the aux battery has been significantly drained. In this case the batteries will combine, then seperate, then combine, seperate etc until both batteries are fully charged.
One of the main benifits of the Surepower is that its has built in circuitry to absorb voltage spikes when the combining to avoid any unnesssecary wear on your factory equipment.
It also has a million plus cycle life so its built specifically for this application. Provided you have no excessive draw on your starting battery while the motor is off, the surepower will always make sure the starting battery is charged (over 13.2v) then charge your aux battery while maintaining a full charge on your starting/priority battery.

Hope I didn't muddy up the water.:D

[docdrs]

Newt ...i believe that it will not separate till voltage drops below 12.9 volts when the system is charging. the actual voltage of a 100% charged battery is 12.73 volts . there is also a delay built in to prevent sensor chattering during excessive voltage changes

[jonyb]

The stereo won't draw enough current to kill the battery unless it's stored like that for a long time. If that will be the case, trip the circuit breaker or pull the fuse. My head unit stays powered constantly and I haven't had problems.

[Newty]

Your right I forgot about the delay. So it will not combine untill 13.2 and will stay combined until aux battery pulls the starting battery to 12.8. (taken off of the link pasted earlier)
Thanks DOC.
Either way for $50-$60, its a heck of a simple fix for adding an aux battery, w/o getting too complicated.

[Okie Boarder]

jony,

Those "stingers" you have in your boat are on-board chargers, right? Do you also have some sort of switch and isolation set up or do you have those batteries offline from your motor's charging system and only charge them with the onboard's once done for the day?

[saltare inverts]

It is supposed to shut off all battery drain. Even the memory in your radio can drain a battery dead so when you shut off the switch it cuts everything off.

[87SunSportMikeyD]

I really like it, because in case my alt belt breaks, and charging stops, then my main battery will die after a couple hours. There should be plenty of juice in the backup battery to start the boat.

[chautauquasun]

The BlueSea is much more expensive than the SurePower, and the perko switch is totally unnessecary when you have the SurePower. The SurePower is a more advanced unit and actually costs less, about $65 after wakeworld discount through brettyates/polarbill. Surepower automatically combines or seperates batteries based upon power consumption, state of battery, which one needs charge, etc.

Are you going to upgrade alt too? Check dbalternator.com for nice american made alt for $80.

Mikey...did you go with the 1314 or 1315? I am adding a stereo to my boat and wasn't going to upgrade to a dual battery but for the price and simplicity of this product I think I am going to plus I have a few deep cycle marine batteries laying around so it looks like a pretty inexpensive way to make sure i dont kill the starting battery when we are listening to tunes.

[jonyb]

jony,

Those "stingers" you have in your boat are on-board chargers, right? Do you also have some sort of switch and isolation set up or do you have those batteries offline from your motor's charging system and only charge them with the onboard's once done for the day?

Stinger is the brand name. The 3 black boxes are charger/maintainers that are built for the 3 batteries. The batteries are dry-cell AGM's. The 2 big ones are SP1500D's that power only the amps. The smaller battery is the SP800. It powers the boat, and all accessories just like the OEM batteries did, except there's just one. I still have the original battery switch, so the alternator can send current to either the 800 alone, or both 1500's. Remember, the alternator is not a charger. I normally keep the switch on battery 1 (SP800).

[87SunSportMikeyD]

Chaq went with the 1314 per brettyates/polarbill's recommendation.

[chautauquasun]

thanks Mikey...I am going that route as well.

[87SunSportMikeyD]

It is just a small square of circuitry. You bolt it to the compartment's wall. Good luck! Don't forget the new alt too! dbalternator.com

[chautauquasun]

I am looking at running two batteries this year using the Surepower system. I have a question....If I am running the stereo and it drains the reserve/stereo battery with it then switch over to the starting battery and drain that one too? I think you answered my question above but want to make sure.

Also, do I need to upgrade the Alt? This has more to do with the time it takes to charge everything back up. Correct?

[87SunSportMikeyD]

The SurePower is both a battery seperator and combiner. The system keeps the batteries seperate for everything except starting-assist IF the main battery is low. Your stereo would be hooked up to your 2nd battery. So if you drain your stereo, it is dead (hypothetically). Then you would start your boat and the SurePower would link batteries and begin charging both. Since the batteries are now linked you would get stereo power back as long as you were driving and charging.

You do not NEED to upgrade the alt but I would highly recommend it because it's very easy and cheap. You likely have a 35amp alt now, my new one is 105amp. Also it has better internal circuitry to be sure the alt is providing a steady current that doesn't jump around or surge so much. (Again I am not a mechanic so I am explaining to the best of my ability. No flames, but positively worded corrections are WECOME)

http://www.db-starter-alternator.com/Items/adr0334%20-%2010si-marine%201-wire?sck=6745929&caSKU=adr0334%20-%2010si-marine%201-wire&caTitle=NEW%20105%20Amp%20Delco%20Marine%20Alterna tor%20Mercruiser%201-Wire%20ADR0334

Here is the one I got but you may want to look at your current setup and call this company. I think it was Ron at DB. He was SO smart! The alt is made in USA with 1yr warranty for $70.

[jonyb]

The SurePower is both a battery seperator and combiner. The system keeps the batteries seperate for everything except starting-assist IF the main battery is low. Your stereo would be hooked up to your 2nd battery. So if you drain your stereo, it is dead (hypothetically). Then you would start your boat and the SurePower would link batteries and begin charging both. Since the batteries are now linked you would get stereo power back as long as you were driving and charging.



So it links the dead battery and the charged battery together, thus dragging down the charged battery. Would that not be correct?

What I've done in the past with situations like that, is to use a 200A Relay/Isolator. If does basically the same thing, but instead of using the ignition key to trigger it to connect, I wire in a manual toggle switch. That way the boat owner can leave it separated until the boat is started and idling, then flip the switch and connect the batteries. That's only if they don't have an onboard charger because it's pointless at the end of the day to connect the stereo battery to the alternator for a 10 minute ride back to the ramp.

[87SunSportMikeyD]

The SurePower would not link the dead stereo batt with the full main batt untill after you were starting and driving about 1000rpm. The SurePower can use the 2nd battery as starting assist if the MAIN battery is low but otherwise it will not use the 2nd battery at all except to charge it.

Personally I don't have that kind of drain, I can run my stereo for days (a long time anyways) off of my deep cycle battery without draining it all the way and it's not that expensive of a batt.

Using the SurePower I personally never had to charge a battery last year using anything but the alternator. But I wakeboard all day too, I dont' sit in the cove and bump for more than a couple hours.

[chautauquasun]

Thanks Mikey...I order the Surepower 1314 and i have a several old deep cycle batteries that are still good. I am going to wire the stereo directly to the deep cycle battery and use the Surepower to connect my deep cycle and high amp starting battery together. Looks to be a very clean and simple way of doing this. I like that there are no switches to worry about and the Surepower system makes all of those decisions...it can then just worry about listening to tunes and not worry about not starting when I am ready to leave.

DB electrical is a great vendor. I bought a fantastic starter from them last year very cheap and with a great warranty. I cant say enough good things about them or the starter.

thanks for all of your help on this. I now know exactly how I am going to wire everything up.

thanks

Dan

[jonyb]

The SurePower would not link the dead stereo batt with the full main batt untill after you were starting and driving about 1000rpm. The SurePower can use the 2nd battery as starting assist if the MAIN battery is low but otherwise it will not use the 2nd battery at all except to charge it.



I was unsure of that......

[87SunSportMikeyD]

Chaut great to hear! Yup it is super simple and no switches. I agree about the DB elec too they really took good care of me.

I have used it for a year and am very happy. I really dont even notice it's there. The new alt lends a lot of piece of mind too. I should really get brettyates/polarbill in here to talk about it. :)

[Okie Boarder]

I'm starting to figure out which way I'm going to take this. Does anyone have pics they can post of their set up? I'd love to see the connection configuration on the sure power as well as any others.

[smoothfootn]

Have a perko in my dads tige. It works great. We just select one battery when stopped listening to the redio. When you're ready to go, if it doesn't start on that battery, you still have a completely fresh battery 2. Rest of the time we leave the switch in both so it charges both. REMEMBER that if you let one battery run down and the other is good AND the switch is on both, you have the average of the two voltages. ( 9 + 13 ) / 2 = 11 which is not enough! Be aware if the other system uses both batteries to start after one gets low.

[rludtke]

On my previous boat, I had a system setup using an isolator, I chose the "Hellroaring (http://hellroaring.com/)" one.

It is SUPPOSED to isolate your batteries electronically - so they can both be
charged, but used independently. The one I used has a switch I installed under the dashboard that would allow me to "combine" the batteries if I needed it -


Hi Okie,
I don't have dual batteries in my boat, but if I was going to, I would be set it up like my motorhome, which is just like TG's description. The electronic isolator will keep both batteries charged by the alternator, and yet maintain separation of the "house" and "chassi" systems. My motor home also feature a big, heavy shunting switch on the dashboard that will connect the systems togather to allow you the option of using the "house" battery to start the engine if the "chassi" battery goes dead.

There are a lot of surplus motor home parts on the internet (and Ebay stores) which could be useful source for economical parts.

[Okie Boarder]

Pics of the surepower set up? Anyone? Anyone?

I tried emailing them, by the way. Any suggestions on contacting them...no word back so far.

[jet]

Along this same subject. I want to build a drop-box in the floor of my boat. Yall have any ideas on this?? Just a regular batt-box or something better? What do you think??

[dusty2221]

In our old bu, we cut out the floor the size of the battery box, and dropped the box down in the hole. the handles on the side of the box hold it up, so it ends up sticking up about an inch from the floor max. Worked great fro 10+ years.

[jet]

Thats a good idea. thanks man.

[Okie Boarder]

I've seen a bunch of rebuilds on the Correct Craft Fan forum I'm on. I've never paid close attention, but a lot of them have this type of set up for their battery boxes. I would assume they either do what dusty mentioned or it is a standard art you can buy from Correct Craft.

[mapleleaf]

Not too sure about the Sure Power set up, I bought a Bep VSR dual batt switch used, on here last spring and installed it. Best thing ever, no worries with a back batt..... Especially for my hard starting antique!!

[jet]

Hey Dusty..how did you finish the hole out?? Glass it in, then drop the box? Sticking up a inch or so would be great, that would keep water from getting inside of the box.

[Okie Boarder]

So, does nobody have pictures of their Sure Power set up? I'd like to see how it looks and what the wiring is like. I'm almost positive it is the way I want to go. Inexpensive and simple, it seems.

[dusty2221]

Hey Dusty..how did you finish the hole out?? Glass it in, then drop the box? Sticking up a inch or so would be great, that would keep water from getting inside of the box.

Yeah, We did that hole when we replaced the floor in it. So the cut out was made before the new carpet was laid. The hole was just glassed with the new floor, and then the box just dropped right in. Completely removable.

[BadbluSi]

Ok, I've been doing lots of searching on this topic, need some advice!! On a scale of 1-10 how difficult is this install using one of the mentioned products?? The qoute I got from my dealer was $450!! I think that's insane and am somewhat mechanically inclined. Is there a how to or directions somewhere I haven't seen?!

[Okie Boarder]

Look at the last post of this thread and you can see some pictures of the Sure Power set up I just did.

https://forum.supraboats.com/showthread.php?t=8373&page=4

Power cable from the Sure Power to each battery, ground between the batteries, ground from the Sure Power to battery and you're done other than physical mounting.

[BadbluSi]

Okie, is there any preference between the 1314 or 1315? I'm planning on installing the first amp and tower speakers and am not sure which will fit my application. I'm thinking the 1314 will work, any ideas?!

[Okie Boarder]

I'd say the 1314 would be fine. The 1314 is one way. The 1315 is two way. The difference is the 1314 is going to favor one of the batteries as the primary and only connect to the secondary when the primary is sufficiently charged. The 1315 will favor either battery and I could see where you could find yourself with a sufficiently charged "stereo" battery and a dead engine battery depending on how you wire things up.

I would rather the engine system favors charging the engine battery first then worry about the stereo battery. If the stereo battery ends up dead, oh well...I guess no tunes...but I can still start the boat to go home.

Clear as mud?

[BadbluSi]

I'm thinking the 1314 should suffice!! And tunes or no tunes, I want the boat to start!! Been stuck in the middle of the lake once, no bueno!! Thanks for the help!

[csuggs]

This is a really good discussion, especially since I'm getting ready to rewire my motor. It sounds like since I already have a Perko switch installed on my batteries, I don't need an isolator?
Mine is not wired like some others though. On mine, the positive from each battery goes to the Perko switch and then there is a common positive cable going from the switch to power my panel under the dash. So if I am listening to stereo, it is drawing from wichever battery is selected at the time. Same for charging; whichever battery (or both) is selected, that's the one that gets charged. With this type of setup, is an isolator pretty much useless? I have a Guest battery isolator, but have never installed it.