Upgrade battery, more batteries and/or capacitor

[Tommy Bierly]

I've recently added upgraded my sound system...more speakers, amps, etc... don't judge me. I have an amp for the cabin speakers, an amp for the tower speakers, an amp for the 10s and an amp for the 12 (I said don't judge me)...oh yeah, and a powered bazooka tube. (I said don't judge me)

my initial plan was to add a second house battery - sameexact battery, just two house batteries.

my questions are:
1) is it possible to upgrade the house battery/batteries? Or am I stuck with the group type just based on the rest of the house battery requirements?

2) is it better to add a capacitor or just another battery if my primary concern is length of charge?

Any thoughts or recommendations?

 

[Inthrustwetrust]

You can put in whatever you like, as long as it’s 12v. I upgraded my audio and went with a Renolgy 200ah AGM deep cycle battery, which is advertised a battery for solar system storage. It’s rather large and weighs 100 ish pounds. I also got a killer deal it. If you get a bigger battery you are going to have to take out the old battery tray and put in a new one or utilize something else to hold it in place. Lithium is a popular choice but my Noco tender is pretty new (not lithium comparable) and I didn’t want to get another tender. I got a Wetsounds 6 channel amp, two Rev 10s on the tower, 4 Recon 6s in the cockpit and a Wetsounds stealth 10 sub. Went out to Crab Sunday, after 5 hours of floating I still had 12.6v on the new house battery.

 

[Tommy Bierly]

You can put in whatever you like, as long as it’s 12v. I upgraded my audio and went with a Renolgy 200ah AGM deep cycle battery, which is advertised a battery for solar system storage. It’s rather large and weighs 100 ish pounds. I also got a killer deal it. If you get a bigger battery you are going to have to take out the old battery tray and put in a new one or utilize something else to hold it in place. Lithium is a popular choice but my Noco tender is pretty new (not lithium comparable) and I didn’t want to get another tender. I got a Wetsounds 6 channel amp, two Rev 10s on the tower, 4 Recon 6s in the cockpit and a Wetsounds stealth 10 sub. Went out to Crab Sunday, after 5 hours of floating I still had 12.6v on the new house battery.

Tell me more about this deal....

 

[212s]

my initial plan was to add a second house battery - sameexact battery, just two house batteries.
my questions are:
1) is it possible to upgrade the house battery/batteries? Or am I stuck with the group type just based on the rest of the house battery requirements?

As mentioned you can put in whatever you want. I presume your 24ft boat has dual battery switches for start and house, so simply parallel wiring in a second house battery is very easy, just a pair of short battery cables to connect them and a way to secure the battery is all you need. Ideally you want to install another of the same kind and size. You still would only use a 2-bank charger as one bank is the start, and the second is for the pair of house batteries connected together. Don't worry about a 3-bank charger. You can use one, but unless you put in some kind of switch to disconnect the two house batteries from each other, you're wasting your time. And one bank will charger both just fine - they will naturally equalize each other with a single input charge.

2) is it better to add a capacitor or just another battery if my primary concern is length of charge?

You need another battery. A capacitor is only needed when high current transients draw more than the battery or charging system can provide. The capacitor does not add any listening time, it merely stores energy for brief transient current draws such as lots of power for subwoofer systems at max output. It helps to level out the voltage and current draw when pounding tunes and is typically used in vehicles so headlights don't dim with the beat of the music.

 

[Inthrustwetrust]

Tell me more about this deal....

Home Depo was running $100 off + free shipping, and I had some Home Depo gift cards laying around to use. This was about a month ago.

 

[marcham]

Dual deep cycle house batteries, wired in parallel is probably your best bet. Note that both batteries should be same brand and same age.

They can be whatever size you want, but note that the stators may not charge them fully if deeply discharged, you may need a 120v shore power charger.

Lithium , although expensive, is becoming a viable option, but requires significant changes to the wiring, including a dc-dc charger instead of a battery combiner.

 

[212s]

Lithium , although expensive, is becoming a viable option, but requires significant changes to the wiring, including a dc-dc charger instead of a battery combiner.

Not all require changes...Relion and a few others are producing drop-in replacements with BMS that takes care of the battery for you. You no longer need a lithium compatible charger or anything else. Just drop it in and hook it up...that's the way I'll probably go when my house battery becomes too weak. Sure they're expensive up front, but since they can last 10x longer it becomes cheaper than replacing AGM batteries with more usable stored energy as well. In fact a group 24 75ah lithium can produce 60ah of usable energy to 80% discharge, while a 79ah AGM can only produce 40ah to 50%. Since the lithium can do it day after day for thousands of cycles compared to just hundreds for AGM, the lithium will last for years. The bonus of weighing half as much as lead-acid is nice too if you're using several for trolling motors.

 

[marcham]

Am familiar with that brand, spoke to their tech support last year. They recommended me to use either a lifepo4 compatible alternator (not possible in our boats) or use a dc dc converter. Their current charging instructions publication still seems to reflect that. If you have more recent or different technical info from them I'd love to hear it. I'd love to have smaller batteries which would give me better storage in that compartment.

https://ceb8596f236225acd007-8e95328c173a04ed694af83ee4e24c15.ssl.cf5.rackcdn.com/docs/product/Relion_Charging_Instructions_022421.pdf

 

[FSH 210 Sport]

Am familiar with that brand, spoke to their tech support last year. They recommended me to use either a lifepo4 compatible alternator (not possible in our boats) or use a dc dc converter. Their current charging instructions publication still seems to reflect that. If you have more recent or different technical info from them I'd love to hear it. I'd love to have smaller batteries which would give me better storage in that compartment.

https://ceb8596f236225acd007-8e95328c173a04ed694af83ee4e24c15.ssl.cf5.rackcdn.com/docs/product/Relion_Charging_Instructions_022421.pdf

When I spoke to the supervisor of ReLion’s tech support he stated that with PMG / PMA ( permanent magnet generators/ alternators) charging systems there would not be a problem.

The main reason is that our charging systems/alternators are always at full output, the rectifier / regulator shunts the unwanted energy to ground, these are the same type of systems found in other power sports equipment like dirt bikes, snow mobiles, side by sides etc. So the electron hungry LiFePO4 batteries will just absorb what would otherwise just be shunted to ground. Our systems peak charging voltage is 14.4-14.5 which is the sweet spot for LiFePO4 batteries. The same is true with Battle Born batteries and other brands.

Automotive style alternators regulate the output by changing the magnetic field density on the rotor, or changing the excitation voltage. Automotive alternators can put out a tremendous amount of charge current for their size especially when compared to the oldest automotive PMG type of generator. LiFePO4 batteries have very little resistance when compared to lead acid batteries, and can take all of that current for a very long time while they charge, whereas a lead acid battery and its higher resistance will back down on the amount of current that can be delivered to the battery. This high output is what damaged many auto type alternators in the past.

I quizzed both BB and ReLion extensively about the application in my boat, and the MinnKota MK 330 charger which does hot have lithium specific profile, but it does have an AGM profile which is 14.4 volts, with a 13.6 volt float for 12 hours, the only difference I can see in charging profiles in the new series of Minnkota chargers like mine is that the lithium setting does not have a float voltage after the bulk cycle.

I did have one problem with the BEP Marine DVSR that came stock on my boat with the change over to a 100ah LiFePO4 battery in that the DVSR is looking for 13.4 volts from either the start or house battery which is a charging level voltage as far as the DVSR is concerned. Well the BB LiFePO4 batteries resting voltage of 13.6 is above that threshold so the DVSR closes in the stock / OEM configuration. I put in an Interstate AGM dual purpose start battery over the winter, and when the DVSR closes, the LiFePO4 battery starts transferring power to the AGM battery. So, I had to cut the red wire on the back of the DVSR and connected it to a spare ckt rocker switch. After the engines are started and the voltage on the AGM battery comes up to or greater than the LiFePO4 battery I energize the ckt to the DVSR and the relay closes 10 seconds later paralleling the start and house battery.



In the near future I’ll be using an ignition hot to energize the DVSR through a 300 second time delay relay to give the start battery voltage time to come up before the DVSR closes. It is important that the AGM and the LiFePO4 batteries are not left in parallel while floating … so when the ignition is turned off the DVSR control voltage drops and the relay opens breaking parallel.





If anyone is interested I started a thread about this subject some time back…. https://jetboaters.net/threads/conversion-to-lifepo-batteries.35834/page-4#post-599247

 

[TXtraumaRN]

I basically did the same thing as you did HERE, but you have one more sub than I (for now). Just finished my second battery install. I kept the stock battery to run all the house stuff and installed an Xs Power AGM Battery to solely run my amps and speakers. I also installed a Noco Battery Tender and used Blue Sea Systems Add-a-Battery Kit. I have zero experience with any of this and overall it was fairly easy.