Adding 3rd battery

Handymans342

Well this is odd. So I have the 2 house batteries out and everything runs on the boat like normal. Weird

212rowboat

Handymans342 said:

Well this is odd. So I have the 2 house batteries out and everything runs on the boat like normal. Weird

you may want to check your battery switch, then... it's possible the connect is bridged either by corrosion or breakage... i had this happen to a switch once- looked fine from outside, but when i dismounted it and flipped it over, it looked like it came out of a 16th century shipwreck collection. 

212rowboat

zaverin1 said:

Take longer and cause damage to the cells

i was actually only giving you an 'out' when i interjected the bit about 'same batteries' as it was already understood the batteries would be like as well as same age earlier in the thread..... and you bit back at me.  so, in kind:

even batteries that aren't alike will charge on the same bank, as the charger has no clue about the capacities or conditions of what it's charging. 

a 'smart' charger pushes amps at a voltage until the battery pushes back- and then it backs off to a trickle for maintenance.  'some' of these 'smart' chargers have circuits to sense heat generated and trickle if it goes above a set temperature- regardless of the resting charge.  either way a smart charger simply checks it's work as it accomplishes charge, and fluctuates the charge according to the state of the battery itself.  

the damage is done to the battery that holds less capacity in a bank that is being charged- it is bombarded beyond its limits and the plates swell, and because the battery beside it is still in need of charge, if in the case of a smart charger the charger stops charging due to either heat or inaccurate voltage readings from the smaller battery.  this makes the smaller capacity battery overcharge and the larger undercharge, which destroys them both. 

this isn't rocket science.  it's pretty simple.  if i took a charger made for a single 105ah battery and paralleled 50 'like' batteries off of it, it would take 50 times longer to charge than it would the single battery (if they were all in the same discharge state)- there would be no damage to the battery nor the charger.  zilch.  the only concern is the quality of the charger... it's not going to be happy pushing max amp/volts for periods of time exceeding what it was designed for.  parts would fry due to heat- which goes back to smart chargers that use heat sensors.. it would stop, cool off, and start again... that's all.  

what MT presented is dead on.  

trip_n

im thinking of getting 2 of the duracell 34m agm's==200.00 plus tax.
just trying to make sure my PD=pd2020 will charge them and work as it should

Handymans342

212rowboat said:

Handymans342 said:

Well this is odd. So I have the 2 house batteries out and everything runs on the boat like normal. Weird

you may want to check your battery switch, then... it's possible the connect is bridged either by corrosion or breakage... i had this happen to a switch once- looked fine from outside, but when i dismounted it and flipped it over, it looked like it came out of a 16th century shipwreck collection. 

I will check this out today.  The battery switches do not have a 1 or 2 position. Just says on

JoeStang

zaverin1 said:

I guess I don’t really know your set up Joe when It comes to how many batteries you currently have if you have a battery switch on it battery class and so on
All those details would make a big difference on how you wire and what kind of charger  you install

Right now I've got 1 starting & 1 house battery. I have the following switch that isolates them.



I am going to replace the starting with the same sized battery, and get two new Group 31's for the house. Then mount & wire them in parallel.

After all this discussion it sounds like I CAN do a 2 bank charger, but a 3 bank will bring them back to 100% faster. Is that correct? If so it's only like a $10 difference, so I'll get the 3 bank.

Willhound

Yes, get the 3 bank, just make sure it's one that is capable of hooking all three batteries even though 2 of them will be wired parallel. You might want to consider changing the battery switch also to one that has Off, 1, 2, and Both.
For example, when my switch is on 1, that is starting battery, on 2 it's my two house batteries wired parallel and Both of course, is all. As soon as the engine gets shut off and I'm anchored somewhere, the switch is set to 2 so that I know my starter battery is isolated and no worries about it drawing down from running radios, fridge, lights etc. Then back to 1 when preparing to start and leave.

zaverin1

Yep change out the switch or add another one 

Handymans342

Here are my switches. Look like yours @raybo3??

Handymans342

What a cluster F

Handymans342

So if I turn off the port battery switch and try to start the port motor it sounds like a dead battery

Handymans342

Same thing with the starboard switch

Dream_Inn

My panel is similar, but has a house battery switch as well (just a regular light switch looking type for house).  That is a real mess on the back though.  Wow, I've never looked at mine.

Handymans342

I am looking for @frenchship on this one because the wiring diagram does not show all those wires hooked to the switches

aero3113

@Handymans342 a couple of years ago I took the wires off of my battery switch one by one and cleaned the terminal rings and lugs with some Scotch Brite. I then sprayed them with battery terminal protector. Looks like yours can use that also but you have a lot more wires with having two switches!!

Handymans342

I know. I'm going to have to take a whole Saturday to figure this out

212rowboat

@Handymans342 : that is AWESOME!!!!  

if that were mine, and glory be to Allah it is not- I'd be installing a terminal block wherever you can find the place to mount it.  two, in fact- if for no other reason that to make it simple: take lead off one side of the switch and mount it to a terminal block- continue to next lead, until all of one side is on one block, and the other side on the other terminal block... then- ONE lead from each terminal block to the respective side of the switch- and with all leads zip tied in a nice row leading to each terminal block.  

i mean, i had to study that thing a lot more than i should have to identify the power lead. 

Cableguy Greg

JoeStang said:

zaverin1 said:

I guess I don’t really know your set up Joe when It comes to how many batteries you currently have if you have a battery switch on it battery class and so on
All those details would make a big difference on how you wire and what kind of charger  you install

Right now I've got 1 starting & 1 house battery. I have the following switch that isolates them.



I am going to replace the starting with the same sized battery, and get two new Group 31's for the house. Then mount & wire them in parallel.

After all this discussion it sounds like I CAN do a 2 bank charger, but a 3 bank will bring them back to 100% faster. Is that correct? If so it's only like a $10 difference, so I'll get the 3 bank.

That is the best switch on the market. It turns the house and start banks on/off at the same time. No confusion. I have the same switch on my 280EC from the factory.

Handymans342

I don't know how to handle this. The whole thing is prewired and installed at the factory. Not sure why its working like it is

Dream_Inn

Oh boy, I've been studying Handy's pictures too long as well. I'd say start with the batt 1/2/3 fuses and follow those wires to where they go.  I'm assuming the small switch in the middle is the house battery?  I'd follow those wires as well to see where they go.  I do think it's worth making your own schematic of where the wires go.  It'll take time, but with the symptoms you are having, it is well worth it.  Did you have shore power when you said everything still worked without house batteries?  what did the 12v meter in the cabin read for house?

Handymans342

So I did have shore power on and with both battery switches off, still had 13 volts at cabin meter

bella-vita

Cabin panel switch is in middle (up down switch)with that off their should be no power.maybe battery charger powering panel through that switch?

Handymans342

Yeah its probably wired off the hot side

reneechris14

Your receiving power from the charger. Turn off the breaker for the charger in the cabin and you will go dark.

Stodge

I was thinking the same as @reneechris14 that the battery charger may be supplying the 13V. 

I had to completely replace my charger in my 280 and was told to run direct from the charger to the batteries.   Seems the isolator is the common connection these days.

If I'm reading the diagram below correctly, the switches make/break the connections to the isolator.  The charger also goes to the isolator.  So with the batteries off and charger on you have 12V active in your DC system.

Handymans342

I am replacing the isolator just because its original. 

Dream_Inn

Handymans342 said:

I am replacing the isolator just because its original. 

Mine actually went bad last year (I didn't think diodes would just go).  Replaced it with an identical one.

Handymans342

I went with the Guest

Handymans342

Dream_Inn said:

Handymans342 said:

I am replacing the isolator just because its original. 

Mine actually went bad last year (I didn't think diodes would just go).  Replaced it with an identical one.

How did you know it was bad??

Dream_Inn

Handymans342 said:

Dream_Inn said:

Handymans342 said:

I am replacing the isolator just because its original. 

Mine actually went bad last year (I didn't think diodes would just go).  Replaced it with an identical one.

How did you know it was bad??

Battery was not getting charge even thought the alternator was working.