Trickle charge question

[Pearl dog]

Another (dumb) question guys. Thanks.

I’ve got 2 battery’s wired in parallel and a 4 position switch. If I put my trickle charger on one battery with the switch in both will it charge both batteries? Should I do this? Or should I charge one at a time? If so should the switch be selected to that battery or maybe off?? Does any of this matter?

 

[-Jim-]

Yes, both batteries will charge -just slower than usual with most chargers. This is typically used when you want to maintain batteries, say when you are not using the boat for long periods of time - Like in Winter Storage. Todays chargers are usually smart enough to limit current and will not overcharge either.

 

[brutus]

Another (dumb) question guys. Thanks.

I’ve got 2 battery’s wired in parallel and a 4 position switch. If I put my trickle charger on one battery with the switch in both will it charge both batteries? Should I do this? Or should I charge one at a time? If so should the switch be selected to that battery or maybe off?? Does any of this matter?

If you want even charging put neg on one batterie and pos on other batterie , if you put pos and neg on the same batterie it will charge that one first and then charge the other one, not sure if it makes sense ???, same as charging a batterie bank, pos at one end and neg at the other end , make sense ??

 

[searun]

I have a smart charger, which will cycle the battery to determine the amount of charge and will shut off once it gets to 100%. During winter storage in the shop, I hook up the batteries every couple of weeks to top them up.

 

[seachicken]

If you want even charging put neg on one batterie and pos on other batterie , if you put pos and neg on the same batterie it will charge that one first and then charge the other one, not sure if it makes sense ???, same as charging a batterie bank, pos at one end and neg at the other end , make sense ??

Uh, no, pos on any pos post, neg on either neg post if it's a parallel setup and battery switch set to both (2 12 volt batteries for a 12 volt system). Current will be split between the 2 batteries as mentioned above regardless of where the leads are at. Pos on one end and neg on the other is for charging in series, as in 2 12 volt batteries connected in series and charger at 24 volts.

Edit: I leave by switch off and charge one at a time but that's just me, mostly so I don't forget to turn it off again.

 

[jim morrow]

In general, do not charge 2 batteries in parallel. If they are both exactly the same, age, type, manufacture, condition, then you can get away with it.
Batteries have an internal resistance, and it is hard to know what that is. As soon as one battery is different than the other, the worst battery will take all the charge and the other none.
When you set the battery selector switch to Both or 1+2 then they are in parallel.

 

[CIVANO]

I have the older version of this mounted in my battery area and it works great

 

[BA48]

Battery switch to both batteries energizes your whole boat, I leave switch off, hook charger to one battery and run a jumper from positive post to positive post

 

[brutus]

Uh, no, pos on any pos post, neg on either neg post if it's a parallel setup and battery switch set to both (2 12 volt batteries for a 12 volt system). Current will be split between the 2 batteries as mentioned above regardless of where the leads are at. Pos on one end and neg on the other is for charging in series, as in 2 12 volt batteries connected in series and charger at 24 volts.

Edit: I leave by switch off and charge one at a time but that's just me, mostly so I don't forget to turn it off again.

Not sure what your talking about lol, or you don’t understand what I am saying, I have a tone of batteries, all hooked up on one smart charger, hooked in parallel (12v) all the way up to 8 at times, pos one end of the bank neg at the other end of the bank, batteries all charge even, if you hook up on the same batterie the one will charge then go to the next one and you will never charge even, google it if want.

 

[seachicken]

Not sure what your talking about lol, or you don’t understand what I am saying, I have a tone of batteries, all hooked up on one smart charger, hooked in parallel (12v) all the way up to 8 at times, pos one end of the bank neg at the other end of the bank, batteries all charge even, if you hook up on the same batterie the one will charge then go to the next one and you will never charge even, google it if want.

Oh I see what you are saying, hadn't considered that many batteries in a bank, was just thinking 2. I can see how the small amount of resistance at each battery connection would cause imbalance in charge. Easiest flow would charge first before pushing through to the next otherwise.

 

[Whole in the Water]

I use a Noco dual battery smart charger with an ACR switch to keep both batteries in good shape.

https://www.bluesea.com/products/7610/SI-ACR_Automatic_Charging_Relay_-_12_24V_DC_120A#:~:text=A: An ACR senses when,the charge to both batteries.

 

[Bifmalibu]

I use a Noco dual battery smart charger with an ACR switch to keep both batteries in good shape.

https://www.bluesea.com/products/7610/SI-ACR_Automatic_Charging_Relay_-_12_24V_DC_120A#:~:text=A: An ACR senses when,the charge to both batteries.

I do as well. I leave it on 24/7.