Battery preferences

Wolfboy

Well-known member
Joined
Aug 8, 2018
Messages
75
Fluid Motion Model
C-28
Vessel Name
Magic Hour
MMSI Number
338440967
Given all of Slipaways issues I’ve decided that I’d try swapping out the batteries. I don’t know how old the batteries are so if nothing else I at least start fresh. The question is what type do I get? AGM or lead acid, starting or duel purpose, and how many amps? I’ve read that it’s a good idea to replace them all at the same time but I don’t know they should all be the same type, amps, group or what.
 
The typical choices are AGM or flooded and you will get various opinions on why use one over the other. AGM you do not have to worry about adding distilled water to the cells and they can be placed in any position. The trade off is cost. They can go for as little as $150 each or up to $275. Flooded can be purchased at Walmart for around $90. I use Walmart flooded group 27, usually readily available at any Walmart. You may be able to fit group 31, but it will be tight. Make sure you get marine batteries all the same type. Amperage can range and the way they rate the amperage can be different. The fact is you get what you get when you buy the battery you want. Usually the amps are around 100 for amps or less for amp hours.
When you replace the batteries, make sure your charger is set for the battery type and if you have a solar panel the same. The important thing about batteries, regardless of type, is how well you care for them and maintain them. A large discharge is bad for any battery. Be careful of how many amps you are using when anchored out and be sure all your switches are off before leaving the boat for extended periods. Always keep the batteries topped up and they will last a long time. We can talk about golf cart batteries, but that is for another day. Keep it simple.
 
My plan right now is to go with AGM batteries with a starting type for the engine and deep cycle for the house and thruster batteries. The pro sport charger says to remove the jumper to convert it from lead acid to gel but doesn’t mention whether or not to remove it for AGM. Do you know whether or not I remove the jumper?
 
Tim,

I pulled this information off the internet:

AGM (Absorbed Glass Mat) and gel batteries are both examples of VRLA (Valve Regulated Lead-Acid) batteries. ... These abbreviations refer to the safety valves in the battery's lid. In common parlance, the term gel battery is used to indicate both AGM and Gel batteries.

Cheers,
Bob Allan
2016 R-27C
Annie M
 
Before installing different types of batteries be sure to check your battery charger capabilities. The battery charger on my C28 is capable of charging three banks and three types of batteries- AGM, Gel, and Vented. But it charges all three banks in the same selected charging profile. ie., It will not charge one bank in AGM mode and the other two in Vented mode, etc. I bought a vented lead acid battery to replace the AGM cranking battery. Before installing it I checked the charger's owners manual to see how to set it. Good thing I did. Since I didn't hook up the battery I was able to return it and bought another AGM.
 
I went with the West Marine AGM 92 batteries. Once I installed them I clipped the jumper for the Charger. In the process I found the dates on the old batteries. It turns out the house and thruster batteries are 10 years old and the engine battery is 5 years old. Swapping batteries didn't clear up my engine starting issue, but given their ages I'm still glad I did it.
 
check all the cable connections for a good connection. remove, clean, reattach (at both ends)
 
knotflying":37exrpd3 said:
The typical choices are AGM or flooded and you will get various opinions on why use one over the other. AGM you do not have to worry about adding distilled water to the cells and they can be placed in any position. The trade off is cost. They can go for as little as $150 each or up to $275. Flooded can be purchased at Walmart for around $90. I use Walmart flooded group 27, usually readily available at any Walmart.

What exactly do you mean by flooded? Is that another term for deep cycle? Or battery’s cells that are “flooded” with battery acid/distilled water (refillable). I just get blank stares when I ask for a flooded battery at oriely.
 
Here’s a good explanation between flooded, AGM and gel batteries:
https://batteryguys.com/pages/the-diffe ... -batteries
Flooded are wet cell conventional batteries that can be either maintenance free or those that have removable cell caps to check and maintain fluid levels.
Flooded batteries can either be deep cycle for the house battery, “starter” for engine and thruster use or a hybrid for both purposes that is optimized for neither. Deep cycle are best for long period lower current drains and starters are best for giving lots of current for short periods of time.
If you are going to a battery store where they don’t understand the term “flooded battery” I would go to a different store....
 
Thats the thing. The guy at Oriely explained everything the way you just did. But he was just lost on the term flooded. Same thing happened at another place last year. Anyway it makes sense now thank you.

I now have a deep cycle for house and a deep cycle for starter. That means I can run them in parallel right? Is it ground to positive, instead of ground to ground? I want to know more about this stuff...and specifically be able to take all the connections off both my batteries and wire it a couple different ways from scratch. I hear so many varying opinions, I want to try out a few for myself.
 
House, thruster+windlass and starter should not be connected to each other either in parallel or in series. They are separate on purpose so that if you run the house battery down, for example, you can still start the engine because it is on a separate and isolated battery.
If you have multiple house batteries you can connect positive to positive and negative to negative so they are in parallel and have more total amp hours to power your house electrical needs such as refrigerator, water pressure, cabin lights, etc.
Connecting two 12 volt batteries positive to negative and negative to positive puts them in series and doubles the voltage without increasing the amp hours. You don’t want to do this on our boats.
If you need to replace your batteries, which is a good idea every few years, the best advice i have is to reconnect the battery cables exactly the same way as they are now. Label or uniquely mark all cable ends. Take photos of how they are wired before removing them and make sure the battery cables match those photos after the new batteries are installed.
You should not mix AGM with flooded batteries. If you are using only flooded batteries, you can mix deep cycle with starter batteries but try to get ones with the same amp hour ratings.
Ok all you battery experts out there, please correct me if I have any of this wrong! I’m still learning as well...
 
Also you should replace the batteries that are connected such as the house batteries at the same time and all batteries should be the same chemistry. Your charger probably can’t charge correctly an agm and a flooded at the same time as the charge voltages are different.
 
scross":3uk4fxwq said:
House, thruster+windlass and starter should not be connected to each other either in parallel or in series. They are separate on purpose so that if you run the house battery down, for example, you can still start the engine because it is on a separate and isolated battery.
If you have multiple house batteries you can connect positive to positive and negative to negative so they are in parallel and have more total amp hours to power your house electrical needs such as refrigerator, water pressure, cabin lights, etc.
Connecting two 12 volt batteries positive to negative and negative to positive puts them in series and doubles the voltage without increasing the amp hours. You don’t want to do this on our boats.
If you need to replace your batteries, which is a good idea every few years, the best advice i have is to reconnect the battery cables exactly the same way as they are now. Label or uniquely mark all cable ends. Take photos of how they are wired before removing them and make sure the battery cables match those photos after the new batteries are installed.
You should not mix AGM with flooded batteries. If you are using only flooded batteries, you can mix deep cycle with starter batteries but try to get ones with the same amp hour ratings.
Ok all you battery experts out there, please correct me if I have any of this wrong! I’m still learning as well...

All correct and very good advice.
I would highlight what he said about Do Not connect your batteries positive to negative and negative to positive. That does put them in series and adds up the voltages so you will have 24volts or 36volts or 48volts...depending on how many batteries you add. That will cause havoc with your electronics and possibly damage stuff.
You already have weird electrical issues; are you sure a previous owner or shop hasn't already connected your batteries incorrectly?
Good advice to label cables and take pictures so everything goes back together exactly the same way; IF it was correct to begin with. You are doing the right approach to seek help and understand the why and how of everything, so you will know it is correct, THEN label everything so it stays that way.
 
I would be very careful with where you are putting your positive and negative leads and map it out on paper first. I had a job once where I was installing 6 batteries in series and parallel. After correctly installing several stations on the last connection of the last station I accidentally connected a positive to a negative. It was interesting to say the least and me or anyone helping me could have been seriously hurt. Positive lead to negative lead = series. Positive lead to ground = sparks and fire.
 
YukonRon":3au5mul4 said:
scross":3au5mul4 said:
House, thruster+windlass and starter should not be connected to each other either in parallel or in series. They are separate on purpose so that if you run the house battery down, for example, you can still start the engine because it is on a separate and isolated battery.
If you have multiple house batteries you can connect positive to positive and negative to negative so they are in parallel and have more total amp hours to power your house electrical needs such as refrigerator, water pressure, cabin lights, etc.
Connecting two 12 volt batteries positive to negative and negative to positive puts them in series and doubles the voltage without increasing the amp hours. You don’t want to do this on our boats.
If you need to replace your batteries, which is a good idea every few years, the best advice i have is to reconnect the battery cables exactly the same way as they are now. Label or uniquely mark all cable ends. Take photos of how they are wired before removing them and make sure the battery cables match those photos after the new batteries are installed.
You should not mix AGM with flooded batteries. If you are using only flooded batteries, you can mix deep cycle with starter batteries but try to get ones with the same amp hour ratings.
Ok all you battery experts out there, please correct me if I have any of this wrong! I’m still learning as well...

All correct and very good advice.
I would highlight what he said about Do Not connect your batteries positive to negative and negative to positive. That does put them in series and adds up the voltages so you will have 24volts or 36volts or 48volts...depending on how many batteries you add. That will cause havoc with your electronics and possibly damage stuff.
You already have weird electrical issues; are you sure a previous owner or shop hasn't already connected your batteries incorrectly?
Good advice to label cables and take pictures so everything goes back together exactly the same way; IF it was correct to begin with. You are doing the right approach to seek help and understand the why and how of everything, so you will know it is correct, THEN label everything so it stays that way.

I’m not aware of anything the previous owner did. Thats why I want to know what each lead is for. I have a starter and a house, both deep cycle. I numbered each lead when I first got the boat so I’ve replaced both batteries since then just followed the existing wire setup. Now I want to label each one with what it’s for and understand if everything is wired correctly.

The reason I brought up positive to negative was people talk about running their batteries together to prolong battery life. And they monitor their batteries often. Either that or they switch between batteries.
 
On my new to me 2012 Ranger 27, the thruster battery was an Interstate AGM and needed immediate replacing after doing a load-test on it. The battery showed a good surface charge but failed the load test. All the batteries were AGM, I replaced it with an Interstate AGM because their warranty was great and they replaced it at no change.

I have done 65 projects of repair or replacement on this tug. One of the best projects was adding a Xantrex Lite battery monitor for the house batteries. It has taken the guess work of using voltage levels of how the house batteries are doing. What I have learned? The solar panel will keep up with the amperage used by the refrigerator, after 24 hours at anchor, the house batteries are down to 75%, after 48 hours at anchor the house batteries are down to 52%. Why is this important? AGM and flooded batteries can go down to 50%. The engine will fully charge the house batteries in 4 hours when the RPM is at least 1,400.
 
Back
Top