How much battery do I need for my stereo system?

[BrandonG]

I am looking to power my stereo system off batteries separate from the starting battery for my 2019 AR195.

The OE setup has 4 small Polk audio speakers connected to the Clarion headunit and I am adding 2 Wetsounds REV 10 tower speakers powered by a Wetsounds Sinister SDX2.

The Rev 10's are 4 ohm impedance so the specs on the amp say at 4 ohm it runs 2 X 400w @ 58A.

Most of the trips I will be taking the boat on will be multiple day trips and it would be nice if I could get up to 30 hours run time before having to charge the batteries.

I dont know how to calculate how much battery this would require which is where Im asking for help.

The specs on the batteries Im looking at are group 27 flooded deep cycle marine batteries and the specs say they are 90 amp hour- 575 cold cranking amps at 0 degrees and 175MIN @25 amps.

I realize there are alot of variables depending on what the volume is set at ect but given the specs how many hours could I get with 2 or 3 of the batteries when listened to at say 75% of max volume output or is there any more specs I need to be able to figure this out?

Thanks!

 

[Jaylex]

grab 2 of the group 27s and you should be fine. I think you want to look at the reserve capacity and amp hours, higher the better.

That WS amp is prob pretty beefy, so you might wanna get 2 vs 1 to have room for growth.

 

[DavisAR195]

For the last two seasons I have been running one battery on a 2017 AR195 with the stock speakers running off the head unit and 2 Exile SXT9Q tower speaker off an Exile amp running 300w at 4ohm for each.

I’m generally out for 4 to 6 hours at a time and anchor for 2-3 hours. I run the stereo entire time of the stock interstate battery and never once had an issue or concern starting the boat.

 

[BlkGS]

I am looking to power my stereo system off batteries separate from the starting battery for my 2019 AR195.

The OE setup has 4 small Polk audio speakers connected to the Clarion headunit and I am adding 2 Wetsounds REV 10 tower speakers powered by a Wetsounds Sinister SDX2.

The Rev 10's are 4 ohm impedance so the specs on the amp say at 4 ohm it runs 2 X 400w @ 58A.

Most of the trips I will be taking the boat on will be multiple day trips and it would be nice if I could get up to 30 hours run time before having to charge the batteries.

I dont know how to calculate how much battery this would require which is where Im asking for help.

The specs on the batteries Im looking at are group 27 flooded deep cycle marine batteries and the specs say they are 90 amp hour- 575 cold cranking amps at 0 degrees and 175MIN @25 amps.

I realize there are alot of variables depending on what the volume is set at ect but given the specs how many hours could I get with 2 or 3 of the batteries when listened to at say 75% of max volume output or is there any more specs I need to be able to figure this out?

Thanks!

You could assume 75 Amps per hour of use, with additional power use for thinks like the bilge and phone chargers and stuff. 2 batteries with 90 amp hours would be180 amp hours, so you could get 2-2.5 hours of play time if you were at max volume with no engine use.

Scaling down is tough, if you're at 50% volume it's hard to say how many amps it will pull without clamp meter readings.

 

[Mainah]

Calculation is a bit tough on lead acid batteries given the variables that will impact them. Lets say you have 100ah battery and are drawing 20 amps rms that battery may last 4 hours in the real world depending on factors like heat, peak draw, etc. Now lets say you are drawing 100 amps rms. That battery may not even last 10 minutes before the volatge drops enough to cause stuff to cut off. Bigger batteries or multi battery systems (they split the load) handle higher rms draw rates better than smaller ones. If you are going to be playing very loud when floating using lead acid batteries the math is far from linear.

If you are going to run ballast pumps or other very high draw items for only a few minutes one tip is to combine the start and house banks for that small period of time to split the stress of the high draw.

The amount of time the engines are at mid to high rpms will also be a major factor.

 

[BrandonG]

Thanks for the help guys. I already bought a 3 bank charger for the boat so I am just going to go with three batteries at this point. That should give me a full day of listening for sure.

One thing I am looking into is adding a Minn Kota on board alternator charger.. It basically takes excess power from the alternator and uses it to charge the batteries, this should help a bit while wake boarding. Has anyone ever used one?

 

[PaulyB]

I have 4 Rev10s, a 12 inch sub, 4 XS650s, a SD2, HT-2 , and HT-6 and I can run for about 7-8 hours at full blast with 4 Group 27 AGM batteries.

If I am going to be out longer I take a Honda EX2000 quiet generator with me and I will use that towards the end of the day. If I dock somewhere without power, I use the generator overnight to charge the batteries back up. Otherwise, plug the boat into shore power at the end of the day and you will be ready for the next day. I think looking for 30 hours without recharging would be pretty hard to achieve, even if you aren't going to run a subwoofer. But you should be fine with 3 batteries for an 8 hour day.

 

[Mainah]

Thanks for the help guys. I already bought a 3 bank charger for the boat so I am just going to go with three batteries at this point. That should give me a full day of listening for sure.

One thing I am looking into is adding a Minn Kota on board alternator charger.. It basically takes excess power from the alternator and uses it to charge the batteries, this should help a bit while wake boarding. Has anyone ever used one?

Yamaha jet boats do not have alternators. They have stators and the minn kota device will not work. I am not familiar with it but can say for certain it won’t work and it may even be harmfull to ignition for the engine. If our boats had alternators we would be talking a lot less about batteries. Stators just dont make near the juice an alternator does and that is the issue.

3 batteries are going to be heavy and iff all on one sode will likely list the boat. Two group 31s and and an inverter were enough to slightly list my 242. You may consider locating one of the batteries on the other aide of the boat. The closer you can get the batteries center line of the boat the less it will have an effect.

 

[Mainah]

I have 4 Rev10s, a 12 inch sub, 4 XS650s, a SD2, HT-2 , and HT-6 and I can run for about 7-8 hours at full blast with 4 Group 27 AGM batteries.

If I am going to be out longer I take a Honda EX2000 quiet generator with me and I will use that towards the end of the day. If I dock somewhere without power, I use the generator overnight to charge the batteries back up. Otherwise, plug the boat into shore power at the end of the day and you will be ready for the next day. I think looking for 30 hours without recharging would be pretty hard to achieve, even if you aren't going to run a subwoofer. But you should be fine with 3 batteries for an 8 hour day.

4-group 27s is a great setup for that kind of power demand all day. Splitting the current draw between the batteries is really helping them last that long.

 

[BrandonG]

Pauly that boat has to be about the loudest thing on water with that setup! Based on what you have I feel confident I could get 2 days of boating on a full charge running just my 2 REV 10's and the Stock radio system.
I am probably going to end up buying a generator though, I run a 36V MK terrova on my fishing boat that I use all day fishing and have noticed at tournaments quite a few guys are running those generators to charge on the go so I can use it for that and my AR

I didn't realize these boats didn't have an alternator, haven't looked too closely in the engine bay, I figured since it was an inline 4 it would have a V belt driven alternator. Thanks for that info Mainah!

 

[PaulyB]

Pauly that boat has to be about the loudest thing on water with that setup! Based on what you have I feel confident I could get 2 days of boating on a full charge running just my 2 REV 10's and the Stock radio system.
I am probably going to end up buying a generator though, I run a 36V MK terrova on my fishing boat that I use all day fishing and have noticed at tournaments quite a few guys are running those generators to charge on the go so I can use it for that and my AR

I didn't realize these boats didn't have an alternator, haven't looked too closely in the engine bay, I figured since it was an inline 4 it would have a V belt driven alternator. Thanks for that info Mainah!

Sorry I wasn't thinking, I have 4 group 31s not 27s.

 

[Mainah]

Sorry I wasn't thinking, I have 4 group 31s not 27s.

Holy Electrons Batman!!!

 

[BlkGS]

3 batteries are going to be heavy and iff all on one sode will likely list the boat. Two group 31s and and an inverter were enough to slightly list my 242. You may consider locating one of the batteries on the other aide of the boat. The closer you can get the batteries center line of the boat the less it will have an effect.

Interesting... i'm about to put 3 batteries and 2 amps over there... maybe i need to rethink that. Blah!

 

[PaulyB]

Interesting... i'm about to put 3 batteries and 2 amps over there... maybe i need to rethink that. Blah!

With a 23 foot boat it won’t be as noticeable. But you will want to put your passengers on the starboard side more often.

 

[BlkGS]

With a 23 foot boat it won’t be as noticeable. But you will want to put your passengers on the starboard side more often.

Well it seems like that happens alot already, plus I will be standing on that side. I keep the second anchor on the opposite side so hopefully it will be OK.

 

[Mainah]

It is not hard to relocate batteries to the other side. Just run some 0 awg through the engine compartment. If installing amps in the helm one can then run the wire from the batteries on the starboard side.

To be honest the slight list is most noticeable when the passenger load is also more to the side the batteries are on. Trim tabs with an auto gyroscopic controller fixed that for me. When my batteries need replaced a few more years down the road I am likely going to drop in high performance lithiums. That wil save over half the weight with even more ah and less volatge drop for better bass.

 

[BrandonG]

I did end up going with three after talking to wetsounds, I am also going to probably keep a small generator locked up in my truck somehow to charge when off the water. Bass Pro Shops had a pretty good deal on their deep cycle 27's.. 114$ VS 194$

 

[PaulyB]

Sams has deep cycle 31 AGM batteries for 159

 

[BrandonG]

Too late now but that's good to know as I may have to buy trolling motor batteries for my fishing rig

 

[Rootbeer Float]

For the last two seasons I have been running one battery on a 2017 AR195 with the stock speakers running off the head unit and 2 Exile SXT9Q tower speaker off an Exile amp running 300w at 4ohm for each.

I’m generally out for 4 to 6 hours at a time and anchor for 2-3 hours. I run the stereo entire time of the stock interstate battery and never once had an issue or concern starting the boat.

I have the same boat. Did you put a Subwoofer in ? Or did you just add the 2 exiles and amp to the boats stock set up? How does it sound ?