Question about switching to AGM

[orexismd]

When I purchased a 2019 210 FSH I received two flooded starter batteries. Upgrading the stereo system and adding a JL 500/5 amp and bought two of the Sams club Duracell 31 AGMs. Two questions.

1. Are there any problems with keeping a flooded battery as a starter and running two AGMs in parallel as the house? I have a solar charger I can use for the flooded battery and a two bank Promariner for for the AGMs. Or, would it be better to just use the two AGMs - one as a starter and the other as the house ( switching the knob to run parallel if needed- ballast pumps/air pumps)

2. Does having two different battery types cause any conflict on how the strator or dvsr deliver voltage? Don't want to damage the AGMs. Have yet to do the DVSR mod which i plan to do. Are there any steps that need to be taken to re-calibrate the battery sensor module/ equivalent system to let it know the battery has been replaced as to prevent overcharging and early failure?

 

[props2you]

1. Nope, I, among many have this set up. The DC's have more CCA's too for the starting battery and run the AGM's for your house.

2. Nope, DVSR regulates the voltage to not overcharge them. No need to recalibrate as the systems decisions are based on the battery feedback/voltage, whether to charge or idle.

 

[Bruce]

I have two 5 year old AGMs. They are diehard group 31 platinums. I have them wired where I can use one, the other or both to serve both starting and house needs. I also have a low voltage disconnect that prevents them being discharged below 50%. I do not have or need A DVSR. This system works best for my constant refrigerator load. I could add a third small battery for starting but the starter load is so small that it is not an issue.

You can read about my setup at

https://jetboaters.net/threads/my-unusual-alternate-dual-battery-setup.5632/

 

[JBehrens]

I run a group 31 Duracell from Sam's and a group 24 led acid that came with the boat. Have had no problems, I do not use a DVSR but have a simple 2 battery switch and alternate use. The group 31 is mostly for playing music when not running.

 

[ralphsmithiii]

1. Nope, I, among many have this set up. The DC's have more CCA's too for the starting battery and run the AGM's for your house.

2. Nope, DVSR regulates the voltage to not overcharge them. No need to recalibrate as the systems decisions are based on the battery feedback/voltage, whether to charge or idle.

@sofakingbig I don't see it in your signature but do you run an aftermarket stereo and if so, what's the setup? Also to clarify, are you running just two AGM's and not a float + 2 AGMS as house batteries?

I'm still not 100% sure which direction I should go. I now have a fairly beefy stereo but haven't spent more than 1-2 hours parked with it on, yet. Still on the factory 2-float start batteries but I know that's not going to last very long. Trying to determine if I need/should run 2 AGM's like @orexismd was asking, or 1 float + 1 agm, or 1 float + 2 agms.

 

[props2you]

@sofakingbig I don't see it in your signature but do you run an aftermarket stereo and if so, what's the setup? Also to clarify, are you running just two AGM's and not a float + 2 AGMS as house batteries?

I'm still not 100% sure which direction I should go. I now have a fairly beefy stereo but haven't spent more than 1-2 hours parked with it on, yet. Still on the factory 2-float start batteries but I know that's not going to last very long. Trying to determine if I need/should run 2 AGM's like @orexismd was asking, or 1 float + 1 agm, or 1 float + 2 agms.

Hey @ralphsmithiii I do run an aftermarket system. I have a 10" sub and 800 watt amp powering the system with the stock connext head unit and stern unit. I have 3 total batteries on board. My house set up consists of 2 Duracell GRP 31's and my start is GRP 24 Dynamic deep cycle. I use the stock solar solar charger to trickle charge the system, I do not run a separate float charger or shore charger.

https://jetboaters.net/threads/the-...et-boat-today-thread.2661/page-89#post-372815

My previous set up was 2 GRP 24 Dynamic deep cycles (stock from dealer) and that would get me about 4-6 solid hours on the water with the aftermarket stereo set up.

The demand to start these engines is fairly minimal, so you'd be fine with a single DC battery. Your power demand will be from your stereo. For that exact reason is why I decided to upgrade to 2 AGM's on the house and run the 2 AGM house batteries parallel to double their capacity. 2 GRP 31 AGM's will give you more than enough run time without having to worry about running our of juice. Just be sure you get appropriate gauge jumpers and coast guard approved trays and straps for your added battery(s).

If you poke around and do some searching on here you will find that to be the most common set up for these boats. Most set ups are pretty similar in the context of most are running 600-800 watt amps with 10"-12" subs and powering 6-8, 6 1/2"- 8" speakers throughout the boat.

 

[ralphsmithiii]

@sofakingbig

After I posted earlier, I looked at my bookmarks and saw I had asked a similar question in an older thread before I added the second round of stereo upgrades. My current system now consists of a JL M800/8 amp and now a M600/6 powering 6 6.5's, 2 8.8 towers and now 2 10" subs. I suppose I can swap out the factory float group 24 house battery for 1 of the group 31 Duracell AGM's from Sam's and see how that holds up. Part of me says just buy two of the 31's and use both for the house and leave the start the factory float 24 (similar to what you're running) and call it a day.

Question: When you cable them in parallel are you just running a jumper power and ground from the 1 31agm house directly "parallel" to the 2nd one? I'll look around for a wiring schematic in the meantime but figured I'd ask.

 

[props2you]

@ralphsmithiii

No Worries! Agree with the part of you that says to add the 2 AGM's. With that type of power demand from your stereo system, I would be cautious & conservative and go with the 2 GRP 31 AGM's for your house. Keep in mind, with the low starting demand requirement of these 1.8's you're better off using that AGM for the house. Dedicate the GRP 24 float to your start and let your 2 AGM's power the house. AGM's typically will have a less "Cranking Amperage" than the DC/Float. Like the old adage goes- "I'd rather have it and not need it, than need it and not have it"!

Wiring is incredibly simple, once you have your connections set for the start & house, your 2nd house will simply connect + to + and - to -, again, just be sure you have trays and straps with appropriate cables. Best explanation: (disregard the unbalanced charging as you're only running 2 batteries.)
How to Charge Lead Acid Marine and RV Batteries in Parallel


Here is what I used:

Trays:
Amazon.com: NOCO BT31S Group 24-31 HD Battery Tray for Automotive, Marine and RV Batteries: Automotive

Cables:
Amazon.com: InstallGear 5 AWG Gauge 2ft Battery Power Inverter Cables for Solar, Auto, RV & Marine - 99.9% Oxygen-Free Copper (Set): Automotive

 

[tabbibus]

Guys, sorry to hijack. Quick question. If you have a DC starter and say a deep cycle for house, can you use a NOCO genius 2 bank charger for both or do they both have to be the same type of battery.

 

[MicahH]

I have a deep cycle for starting and AGM Duracell 31. I have the ProSport 2 bank onboard charger and it works great. The setting is flooded/AGM as both are flooded style cells. I’m not positive but believe the Noco works the same.