Battery bank guidance

walleye

Trying to get a handle on what powers what in regards to my battery bank. The two batts on the left of the attached pic are 24s. The two on the right are 27s. Should I assume each of the 24s is dedicated to one engine only for cranking? If so would one of the 27s be connected to the geny or would both 27s be paralleled as the house bank? If I need to start disconnecting batteries to figure out what runs what via process of elimination I can do that, though wanted to first see what the collective wisdom was here. I'm clearly not familiar and am an electrical novice at best. Boat is a new to me 320 (2008). Thanks in advance!

Weber

The 27's should be your house batteries, and the 24's should be for the motors.

DanD2

One of those 24's is also for your genny. I suspect it's the one on the right. The two on the right should be deep cell and are your house batteries. The would power things like fridge, lights, TV, 12v receptacles etc.

walleye

Thanks for the feedback guys. To clarify, does each of my 5.0s have its own 24 dedicated to it (with one of them sharing a 24 for the genny)? Or is one 24 for one engine, another 24 for the genny, and the other engine tied to the two 27s? My dock neighbor suggested to me today that it might be the later setup. Would that be possible and make sense?

walleye

Also, I was playing with my battery switches today and noticed that when I had one switch turned off and the other turned on that neither of my engines had power to turn over. (I alternated turning one switch on and the other off; both had the same result - neither engine would turn over). I was under the assumption the engine with its dedicated switch turned "on" would turn over and the one turned off would not. Am I incorrect or do I have a battery issue to deal with? When both batteries are turned "on" both engines start and run normally. 

DanD2

Let's try this again.......one 24 for cranking one engine, the other 24 for cranking the other engine plus genny.  The 27's SHOULD be just your house batteries.

As far as your battery switches, some boats are different and some switches are different, I'd have to see what it states on each switch (i.e. on/off/emergency/parallel etc.), however one should be for the engines and the other for the house. The switches allow you to isolate the house from the starting or run all your batteries in parallel in case the starting are weak.

redlightning

I have a 330 and two connected are house power.  the other two are one for each motor as far as I can tell. 

walleye

Thanks again, all. Dan, here's a pic of my switches. As you can see the dial switches are for (or claim to be for) each engine. If this is the case, why do neither engines turn over when I have one (either port or starboard) dial switch turned off?

Weber

I have the same panel, if only one switch is on you can only start that motor, both switches need to be on to start both.

Dream_Inn

I agree with Weber. You should not need both switches on to start one engine.  Only that engine switch should need to be on.  Sounds like you may have some wiring incorrect.

rmrstlmo

Not to get too far off the topic....  I have a question regarding the terminals labeled "Hatch Override".  My 2000 340 has terminals like those but they're not labeled.  Are those for attaching a battery pack to raise the hatch if your boat batteries are dead?

JC290

You are correct that is what they are for

walleye

Not sure if this would help diagnose any battery problems I may or may not have, but what should the DC volt meter on my electric panel read when batteries are fully charged and shorepower is unhooked, charger off, etc?

raybo3

About 13volts

Dream_Inn

Probably a tad lower than 13, like 12.8V.

DanD2

Walleye, the DC volt meter is just for the house batteries.

As far as the switches, in looking at your pic, you have the same setup as I do and you are correct in your assumptions. It appears that you have something funky going on or hooked up incorrectly.

MarkB

How are those 2 batteries wired? They didn't bridge them together in such a way that would put them on 1 circuit, did they?

walleye

Alright gang, I have a related issue/question.  While on the hook yesterday,  my TV/DVD (original Rinker AC/DC TV unit) would shut down after a few minutes after my kids would start watching a DVD on DC power (it would start playing movie; then shut down after a few mins.). The TV/DVD works fine when it's operating on AC power. Additionally, it seems I lose "cold" on my cabin fridge very quickly when its operating on DC (works fine and makes plenty of cold when its operating on AC). While on DC power after a few hours my fridge green light is still on, though the red light also flashes (green light only when I'm on AC). Both the TV/DVD and fridge issues were occurring within two hours of being on the hook. I've tested my batteries with a voltmeter and the 27s showed 12.6.  However, it seems that the PO has "starting" 27s installed as opposed to a deep cycle or starting/deep cycle hybrid. 
Thoughts on what could be the issue here?  Are the starting batteries not providing adequate amps to sustain my fridge and/or TV/DVD while on the hook even after just an hour or two? 
For reference, my 27s are the 27M6's listed here: http://www.atlanticbattery.com/category_v3.aspx?categoryID=48

JC290

deep cycle battery would be best, did you load test the batteries? they may show good voltage but not be able to hold

Weber

Load test your batteries, it sounds like you have a lack of capacity.

I had a similar issue, I could tell my fridge was not as cold as it used to be when out on the water, and the radio and amps would cut out after having it turned up for a while.  Once I replaced them we are good to go.

Weber

Also when you check voltage, make sure you disconnect them.  You could be reading 12.6 but one battery may only read 11.6 when it is disconnected.

walleye

Thanks. I did not load test but will do that. If I need to replace the 27s I will do so with deep cycle (as opposed to the current 27 starters). If I did that could I leave the current 24s (assuming they are in good shape) or would I need to replace them too? I've read some about always replacing all batteries at the same time but does that mean in my situation replacing both 27s as opposed to just one, or does it mean I'd also want to add new 24s too? I don't want to screw anything up. 

Cableguy Greg

Starting batteries drain very fast. I would replace the house batteries with deep cycle batteries. If you can swing it, group 31's would work best. Sam's Club has a great price on Group 31 AGM deep cycles that are made in the USA by Deka.

Hamdog

You do not have to replace the starter batteries too. Just replace the two 27's with the biggest deep cycles that will fit. On a 320, you definitely want to go up to the group 31's. I have 2 group 31 (which is simply the size) Lead Acid batteries on my 342 and they work just fine but AGM's are better as long as your charger is compatible. When you read that all batteries need to be replaced at the same time, it just means all batteries in parallel need to be replaced at the same time. Starter batteries can be replaced individually when needed but house batteries are wired together as one bank. Also, make sure you hook the main positive to one battery and the main negative to the other one. Do not hook both to the same battery. Then just use a short cable to jump the positive over to the other positive and the negative over to the other negative. Hope this helps.

walleye

Appreciate the info and handholding on this! Both sets of batteries are currently lead acid. When I replace the 27s would it screw up my system if the replacement type was something other than lead acid (eg, AGMs)? Would two different types of batteries charge appropriately if hooked to the same charger or do I need to keep them all lead acid?

Dream_Inn

Walleye, you will need to look at your battery charger (& maybe Google a manual for it if you don't have one).  If the charger can take AGMs, then you should be ok.  You would probably have to change a setting on it as well.

frenchship

Here is the best way to hook up both batteries in parallel .

DanD2

As far as AGM batteries and the charger, your charger may be able to handle AGM's but be sure it can handle the different type on a per bank basis. Some chargers. just because it can charge AGM's does not mean you can put lead acid on a different bank.

rmrstlmo

The charging profile of AGM vs lead acid is pretty close.  I recently replaced my single house battery with AGM (was lead acid).  Both starting batteries are lead acid.  I switched the charger to AGM setting to favor the new house battery.  Everything has been working fine for a couple of months. When the starting batteries give out I'll replace them with AGM.

Hamdog

I went with lead acids again because the first set of house batteries lasted for 5 seasons and the starter batteries are still going strong into the 6th season. I would have gone AGM except I didn't want to mess with the charger and the current setup. Worked for 5 years so figured why change something that was working. Just do not skimp on the batteries. I paid about $125 per deep cycle lead acid battery which were what my marine service guy said were the best ones he could get.

walleye

Thanks all. Very helpful.