Dual battery....opposite situation of Tonka.....HELP

[Kahuna Khris]

I have been getting low voltage warnings on my 2016 FSH Sport boat gauge (with alarm) and low voltage warnings on my Humminbird fishfinder as well. I have to turn on the parallel isolation switch to temporarily resolve the issue. I tested the batteries and the start battery was low (8.5 V) while the house battery (an identical battery) seemed fine. I had the start battery tested and am replacing it as it failed the load test. My issue is this......When I pulled the start battery, which is a starting battery, I noticed that the house battery is also a starting battery. Shouldn't the house battery be a deep cycle? I want to replace both at the same time but am not sure if they are the same due to charging requirements etc. I was just going to replace them with two starting batteries, as that is what the dealership installed, but then noticed this post that Tonka's came with two deep cycle batteries. HELP!! I have lost faith in the dealership's opinion as I have learned over the years that I know more about this boat than they do. Neither of these batteries are used to power my 36V Riptide as I have 3 dedicated batteries and charging system for them. House battery used for Humminbird, radio and Canon Mag 10 downriggers. Boat motor is off when I use this equipment as I can troll with the Riptide.
Batteries are both Napa Marine 24M-7, (800 cca /1000 ca) starting batteries (see pics below). They are approximately 2 1/2 years old.

So I don't want my question to get lost in all of the background. Should I install a starting battery as the start battery and a deep cycle as the house battery? If so, do they have to have identical ratings and will my charging system (boat alternator) be OK with the two different batteries?

Opinions please.

Attached Files:

 

[Brian Filas]

I have had similar issues. I have never determined if the alternator charges both batteries or just the starting (I assume both). Even if it does charge both, the way I fish (motor to the spot then use the trolling motor to fish) means the engine is off most of the time. This means I am pulling more juice off the house batter, than the alternator can put back into the battery. To fix this, I have one bank, of my 3 bank charger, charging the house battery (starting usually doesnt have an issue). Just a few weeks ago, I forgot to plug in my charger overnight, went fishing, and got the low voltage alarm on the house battery. Again, the main issue is you draw more than the alternator can put back in (espeically if you are not running the main motor very long). Hope that helps. Here is a link to my overview if you want to see how I set things up.

 

[Brian Filas]

One other point. The other issue to consider with two different batteries is the jumper. As you know, there is the option to put the batteries into parallel. Not sure how having two different batteries would effect the batteries when linked together. Might have to google that.

 

[bronze_10]

Somehow you have created three different threads on the same topic...
Your house battery can be whatever type u want. Some say u need the same batt others say they can be different.

 

[Dough]

I'd use two deep cycle. Jet ski engines don't need a starter battery.

 

[Kahuna Khris]

Somehow you have created three different threads on the same topic...
Your house battery can be whatever type u want. Some say u need the same batt others say they can be different.

That's just ignorance on my part. I didn't want to limit my answers by restricting my post to one forum only as it is a cross-boat issue. Thx for reply.

 

[Kahuna Khris]

[/QUOTE]

I have had similar issues. I have never determined if the alternator charges both batteries or just the starting (I assume both). Even if it does charge both, the way I fish (motor to the spot then use the trolling motor to fish) means the engine is off most of the time. This means I am pulling more juice off the house batter, than the alternator can put back into the battery. To fix this, I have one bank, of my 3 bank charger, charging the house battery (starting usually doesnt have an issue). Just a few weeks ago, I forgot to plug in my charger overnight, went fishing, and got the low voltage alarm on the house battery. Again, the main issue is you draw more than the alternator can put back in (espeically if you are not running the main motor very long). Hope that helps. Here is a link to my overview if you want to see how I set things up.

I found this on another post which should answer your alternator question. With parallel switch off and the start and house switches on, the alternator charges both batteries. (see below).

 

[Ronnie]

I started getting a “low aux voltage” warning a few years ago and replaced two matching batteries with two matching interstate cranking/starting batteries. In retrospect I should have taken @txav8r advice and put a deep cycle battery in for the house / aux battery because now I’m experiencing the “low aux volatile” problem again. The guy at interstate told said the same thing as @txav8r did when I bought the batteries but I didn’t listen. I brought both batteries in to be test and both passed so now to resolve the issue I’m going to replace the house/aux battery with a deep cycle battery. A costly an unexpected lesson I could have avoided.

If you have the stock dual battery system you’re engines stators charge both batteries automatically, one at a time but I don’t know which charges first.

 

[Bubblehead]

I have had similar issues. I have never determined if the alternator charges both batteries or just the starting (I assume both). Even if it does charge both, the way I fish (motor to the spot then use the trolling motor to fish) means the engine is off most of the time. This means I am pulling more juice off the house batter, than the alternator can put back into the battery. To fix this, I have one bank, of my 3 bank charger, charging the house battery (starting usually doesnt have an issue). Just a few weeks ago, I forgot to plug in my charger overnight, went fishing, and got the low voltage alarm on the house battery. Again, the main issue is you draw more than the alternator can put back in (espeically if you are not running the main motor very long). Hope that helps. Here is a link to my overview if you want to see how I set things up.

With Both Start and House swithes on and the emer. parallel off (normal condition), the alternator charges the start battery until it reaches 13.7 volts. At 13.7 volts the Voltage Sensing Relay will close and allow charge voltage to the House battery. If the little red light on the VSR is on, that means it is charging your house battery because your start battery is full charge. If you are having low voltage problems with your house batt and it load test sat; then check the VSR to see if it is operating as intended.

 

[ClemsonTiger]

1 start, 1 deep cycle. Standard config on ALL boats w/2 batteries. Your alternator will charge it fine, doesn't matter if the ratings are different.

Larger boats with multiple engines/outboards and larger draw will have variations of the 1/1 config.

 

[Bubblehead]

Voltage rating must match

 

[txav8r]

If your running an ACR, your best bet is deep cycle. And to clear up common confusion, your charge system isn’t an alternator, and the system doesn’t charge the start battery first always, it charges the lowest voltage battery first. We don’t have the sophisticated software that a motorhome or other equipment might have. The ACR is merely a relay, that has upper and lower limits, and will choose only one path to deliver a charge, that will always he the lowest voltage battery. That said, it may go back and forth a tad as they charge, and generally, the lowest battery will be the one that just started the boat. But our engines do not draw the battery down much at all, so if you have had the stereo on before starting, the house could be lowest. The VSR is different but it wouldn’t make much sense to charge an almost full battery first, and then charge your house, that has spent the afternoon powering your 1500w stereo! I don’t profess to know the VSR like I do the ACR, but I know it’s quirky.

 

[Bubblehead]

BEP makes vsr, blue seas makes acr. My 210 came with BEP. Neither operate by determining which battery has lowest voltage. They operate based on the presence of a charging voltage, something above 13v. If start battery is low and house is dead, then engine charges start until voltage triggers relay to charge house.

 

[Bubblehead]

To add, if you connect a separate charging source to house ie, solar)ola have a dual sensing relay, it will charge house until voltage triggers relay, then charges start

 

[Corey]

Get yourself two identical AGM batteries (Group 27 Optima Blue Tops are what I have, Group27) never an issue with AGM's.

 

[Tonkatoy]

Yes, batteries should be identical since they will be paralleled during charging or emergency paralleled. Deep cycles can start our engines without any issues.

 

[Ronnie]

I got two identical agm interstate starting batteries and am now seeing the low saucer voltage alarm on them that I experienced on another set of batteries two seasons ago. I was told that if I keep the batteries on a dual bank charger / maintainer when not in use (which I do) than the batteries do not need to be identical. That said I plan to replace my aux starting battery with a deep cycle with the goal of getting rid of the alarm. In case the following is not well known, once the low volatage alarm comes on if it is not addressed the stereo and other non essential systems basically everyone but the engines loses power. It really sucks to be on the water without tunes.

 

[Kahuna Khris]

I got two identical agm interstate starting batteries and am now seeing the low saucer voltage alarm on them that I experienced on another set of batteries two seasons ago. I was told that if I keep the batteries on a dual bank charger / maintainer when not in use (which I do) than the batteries do not need to be identical. That said I plan to replace my aux starting battery with a deep cycle with the goal of getting rid of the alarm. In case the following is not well known, once the low volatage alarm comes on if it is not addressed the stereo and other non essential systems basically everyone but the engines loses power. It really sucks to be on the water without tunes.

Yes. First I would get the low voltage warning on the dash, then on my fishfinder, then the fishfinder would shut down...my gas gauge....speedo....everything would shut down, but the boat would keep running. Weirded my out the first time it happened and now in the process of fixing the issue. Thx for reply.

 

[Kahuna Khris]

So I went to the boat yesterday to take out my second battery (start) to have it checked, after replacing the house battery which was bad. What I found was that only the house battery had all of the wires connected to it. The house battery is a starting type battery. The only wires to the start battery were jumpers from the house battery to make it a parallel circuit. (See diagram attached). Also attached is the 190 FSH sport manual showing the battery setup.

Isn't this setup wrong because
1) The start wires should go to the start battery and the accessories to the house, which should be a deep cycle.
2) This setup negates the isolation switches because there is no way to bypass the house battery to just use the start battery.

The dealer installed my accessories so they were aware of the setup as it sits.

 

[Bubblehead]

Positive leads from acc should go to house switch, other side of switch to house batt+, Engine +leads go to Start switch and other side of switch to start batt +, all negatives to associated battery and both batt neg connected. Simplified of course, you should have inline fuses close to batt on +lead to protect wiring. I am sure others will add to this