Maybe a confusing Battery question, anyone??

[wilf]

After the problem on another post about my fridge, another puzzling question arises, after tracing my fridge supply wires back to the battery i found that the + wire was connected to 1 battery and the - wire was connected to the battery next to it and the supply at the fridge was showing 28 to 30 volts,

if i connect both the + and - fridge supply to the same battery it shows around 12 to 13v,
i have 3 batteries, that seem connected to each other , one 12volt battery i just bought new now shows around 28v the other two show 13v each or if i touch + on one battery and - on another they show 28v,
Also i cant figure out if there is just one battery for starting and the other 2 are for house as when on switch 1 everything works, lights, water pressure, motor cranks etc, and on switch 2 everything works too, would like to figure out how to have 1 battery that just starts the engine then i dont run it down, any suggestions anyone ???

 

[Brian D]

Take a picture and post it. If you can't get a good photo then a hand drawing will do. With the information you have given, it would help if we had the battery name and model number for each. Right now, as I read you post I am a little confused. Maybe someone else will understand, but it is always good to have a photo or drawing to fall back on.

 

[wilf]

Take a picture and post it. If you can't get a good photo then a hand drawing will do. With the information you have given, it would help if we had the battery name and model number for each. Right now, as I read you post I am a little confused. Maybe someone else will understand, but it is always good to have a photo or drawing to fall back on.

I will post a picture tomorrow and try to show where each battery is connected to where

 

[Brian D]

I am going to move your thread over to Maine Sail group. He is our resident professor of everything. LOL

 

[wilf]

Heres a diagram showing where each cable is positioned and also showing the volts between the different terminals, does this configuration of the batteries look correct ?

 

[wilf]

The battery i just bought says DC24N the other 2 both have GC2 on them (they are 9 years old but still show 14v) also in the battery compartment there is a battery combiner that is in the on position , however that works ?

 

[Stu Jackson]

http://www.smartgauge.co.uk/batt_con.html

 

[wilf]

Thanks i will look at that

 

[wilf]

I dont know much about electrics but is it strange that 2 of the batteries are connected by the + to - terminals?

 

[walmsleyc]

As it's unlikely you "intend" to have a 24v configuration on your boat, the problem is the two batteries at the top of your diagram and wired in series instead of parallel and thus their voltage is "additive". Does your refrigeration system need 24v?
With the addition of a "shorty" ground cable between the top two batteries, and switching one of the red "shorty", you can be back to a 12v system.

Did you replace or re-wire the batteries recently?

Where do the cables go to? Starter? House loads?
Chris

 

[wilf]

As it's unlikely you "intend" to have a 24v configuration on your boat, the problem is the two batteries at the top of your diagram and wired in series instead of parallel and thus their voltage is "additive". Does your refrigeration system need 24v?
With the addition of a "shorty" ground cable between the top two batteries, and switching one of the red "shorty", you can be back to a 12v system.

Did you replace or re-wire the batteries recently?

Where do the cables go to? Starter? House loads?
Chris

I replaced the bottom battery jyst as the one o removed was wired, i am assuming the 2 red and 1 black cable that go through the battery compartment go to the battery switch or the engine?

 

[Ron20324]

The battery i just bought says DC24N the other 2 both have GC2 on them ...?

Ah-ha! mixed types/voltages, and that is making matters more confusing, but now understand it better.

 

[Brian D]

The GC2 is a 6v battery. In your diagram you have them connected in series for 12vdc. If you are reading a different voltage between the terminals, such as 12v between the + and - terminal of a single GC2, check again to make sure it is not a 12vgc. But you also might be reading a pair of batteries. So I would disconnect the ground to confirm.

The common is just that, common so as it is wired no issue. But... as I see the diagram, you should have total 12vdc on the two BCI GC2 batteries and I would guess this is your house bank. Then you should have 12vdc on the Group 24 single battery. Probably your starting battery.

The two red leads go to your 1-BOTH-2 switch. If you set the switch to BOTH you should still read 12vdc. Where you are getting the 24~30vdc is a mystery to me. Are you sure you do not have more batteries that you are not aware of?

 

[wilf]

The fridge was wired to the + on the top left battery and the - on the top right battery when its wired like that (showing 28v) the control box bleeps and compressor and fan go on and off but if i wire it to same battery i get 13.8v but nothing happens so is it a 24v fridge? i think its a adler barbour PB101V vertical model freezer, on the compressor it says BD 2,5 12v-D thats all i can see on it

 

[wilf]

The GC2 is a 6v battery. In your diagram you have them connected in series for 12vdc. If you are reading a different voltage between the terminals, such as 12v between the + and - terminal of a single GC2, check again to make sure it is not a 12vgc. But you also might be reading a pair of batteries. So I would disconnect the ground to confirm.

The common is just that, common so as it is wired no issue. But... as I see the diagram, you should have total 12vdc on the two BCI GC2 batteries and I would guess this is your house bank. Then you should have 12vdc on the Group 24 single battery. Probably your starting battery.

The two red leads go to your 1-BOTH-2 switch. If you set the switch to BOTH you should still read 12vdc. Where you are getting the 24~30vdc is a mystery to me. Are you sure you do not have more batteries that you are not aware of?

Both the gc2 batteries show 13.8v individualy but 28.4v when i check + on one to - on the other the dc24n battery shows28.4v between its two terminals, dont think theres another battery the seat opposite the battery compartment has a battery charger in it

 

[wilf]

Im not sure if the battey switches were on or off when i was checking the volts, if that would make a difference to tge readings ?

 

[wilf]

Will try to find someone to check it out for me in the next day or 2

 

[Brian D]

Got it wilf. The reason I asked is because normally, and normal is not being defined here, normally a GC2 (Golf Cart) battery is 6vdc and is small is size. So if you are reading 13vdc on a single GC2, then it must be a different model. The GC2 has 3 cell caps, GC8 has 4, and the GC12 has 6.

The other battery, DC24N, is also normally 12vdc. The DC stands for Deep Cycle, the 24 is a Group size, and the N is whatever the manufacture decided it to be. But if you are reading 24vdc, then it is possible you have two batteries in the same housing. Just a SWAG.

 

[wilf]

Got it wilf. The reason I asked is because normally, and normal is not being defined here, normally a GC2 (Golf Cart) battery is 6vdc and is small is size. So if you are reading 13vdc on a single GC2, then it must be a different model. The GC2 has 3 cell caps, GC8 has 4, and the GC12 has 6.

The other battery, DC24N, is also normally 12vdc. The DC stands for Deep Cycle, the 24 is a Group size, and the N is whatever the manufacture decided it to be. But if you are reading 24vdc, then it is possible you have two batteries in the same housing. Just a SWAG.

Do you think the problem could be at the battery switch? I Was wondering that because it doesn't matter if its switchted to 1,2 or all, everything works in any position, lights, water pump, engine turns over etc

 

[wilf]

Dont know if the pic is clear enough but i market the different readings i get between the different terminals if that helps at all?