1,2 Both Switch - When on Both do the 2 batteries even out on charge?

Iif you work in the industry then you are the reason that I post so much to try and educate poor boat owners who are getting fleeced by ignorant experts like you.

You have some accurate and truthful information to share, by all means post it.

So far, all you have posted is inaccurate and ill-informed scare mongering nonsense.

You have no idea of the area of the industry in which i work, although over the past few decades i've worked in most sectors of the automotive industry. I currently sell no products or services, neither do i charge the public for my services, not sure where there is any scope for fleecing people who don't pay me ?
 
Iif you work in the industry then you are the reason that I post so much to try and educate poor boat owners who are getting fleeced by ignorant experts like you.

So what makes you a legendary expert?

So far google cut and paste, no real data and no indication that you've spent any time in the battery business other than having some on a boat. .
 
Or after a bit of time on google, battery death seems to be also connected with the increase in current sucking electronics with led screen displays etc. No mention of high voltage came up in a quick 10 minute google.
Most of that current sucking happens when Mr Alter Nator is in charge....
Although some vehicles draw too much current when parked. I had a bike like this, a BMW K1100. That was really early 90s tech though.
 
Having followed this and other battery threads I have come to the conclusion there is no right answer.

There are a few correct answers, depending upon factors such as personal requirements and budget.

There are also a good few incorrect ones.

Then we have the obligatory bullshit answers :(
 
I think there's lots of right answers but no-one wants to admit that somebody else may be right as well. I'm not even sure what the argument is any more.

No I'm not either but from a personal point of view if I add a 1 2 both switch but wire it to give me a main and emergency bank with a vsr topping up the emergency bank then I will.

Avoid any problems with chatter

Avoid any possibility of overcharging the much smaller emergency battery

Avoid the larger bank pulling down the smaller bank when it's heavily depleted.

Be able to isolate either bank.

Normally only have to switch my main bank on or off.

I think that'll do me...

________________________
 
You obviously got confused by the bullshit posts Shaun.

No I'm not either but from a personal point of view if I add a 1 2 both switch but wire it to give me a main and emergency bank with a vsr topping up the emergency bank then I will.

Avoid any problems with chatter

You do that by fitting a decent VSR

Avoid any possibility of overcharging the much smaller emergency battery

Avoid the larger bank pulling down the smaller bank when it's heavily depleted.

Not going to happen with a 1-2-both or with separate switches.

Be able to isolate either bank.

Normally only have to switch my main bank on or off.

[/QUOTE]

Same as with separate switches.

It's a pity we get uneducated scaremongering that deters people such as yourself from fitting a superior arrangement.
 
If you parallel a flat 55ah battery at say 11.6v with a fully charged 110ah one at say 12.6v you'll get a combined voltage of about 12.25v which may or not be enough to start an engine. So it's not a good idea to parallel batteries up for emergency starting. A 1-2-B switch should enable you to select your best battery for engine srarting which would be better than the seperate switches with a 'combine' one. Provided you have a way of determining the state of charge of each.
 
It's a pity we get uneducated scaremongering that deters people such as yourself from fitting a superior arrangement.

Thanks for your time and patience in responding Paul.

I'm well used to the variety of opinions we get on here. I've only just fitted a 22kg Rocna to my 2 man tender along with a 60hp outboard to "back it in" :D

We have an Eberspacher that we will use a lot because Wifey doesn't like the cold.

I can see we may often have a big disparity in the relative charge of the two banks.

I don't really know why but I like the idea of the alternater pumping straight into the main bank and not via the small starter/2nd bank and a vsr.

As dufour wire the starter and alternator together back to the battery bank I didn't really want to start to separate them if I didn't need to.

Am I just being a Wuss?

_________________________
 
Having followed this and other battery threads I have come to the conclusion there is no right answer.
A lot of time that is true - opinions are just that - not facts. I have tried to sum up my real world experiences of 12 years of living aboard and sailing a Legend 420 - hence my posting name. I have a degree in Electrical Engineering and have used that to optimise the electrical side of my boat. The last 10 years has been in the Med, and my batteries have lasted 12 years so far.

All my controversial "opinions" have been backed up by references to well know manufacturers websites with enough information to keep people busy reading, not posting pointless and malicious answers with absolutely no backup or reference material to suggest that my points are clearly wrong.

I think there's lots of right answers but no-one wants to admit that somebody else may be right as well. I'm not even sure what the argument is any more.
This is a major problem on these types of threads when the argument gets lost amongst the bulls.1t. I have reported this to the Moderators.

Problem is working out the good and bad from the indifferent.

There are nearly 4000 reading this thread in the hope of some answers. I hope they use some of my links, especially phase.com, who is possibly the best source on the internet of good information on batteries and charging. He does extensive tests to prove all of his "opinions" and "nobody" has a bad word to say about hime, except PaulRainbow.
 
Thanks for your time and patience in responding Paul.

I'm well used to the variety of opinions we get on here. I've only just fitted a 22kg Rocna to my 2 man tender along with a 60hp outboard to "back it in" :D

We have an Eberspacher that we will use a lot because Wifey doesn't like the cold.

I can see we may often have a big disparity in the relative charge of the two banks.

I don't really know why but I like the idea of the alternater pumping straight into the main bank and not via the small starter/2nd bank and a vsr.

As dufour wire the starter and alternator together back to the battery bank I didn't really want to start to separate them if I didn't need to.

Am I just being a Wuss?

_________________________

If the VSR and wiring are suitably rated there isn't really any difference whether the wire from the alternator goes to one bank or the other. At the end of the day the CSR will parallel the two banks very shortly after the engine starts anyway. Once that happens you basically have one big battery. There is no need for you to change where your alternator is wired, just fit the VSR between the two banks.

How about some real World stuff :

My boat has a single 110ah engine battery and two 110ah batteries for the domestic bank. The alternator is connected to the engine battery and the solar panels to the domestic bank. Each bank has it's own isolator switch. A dual sensing VSR allows both charging sources to charge all of the batteries. A third switch is fitted for emergency use, should a bank fail.

I also have a mains charger, which since the Sun disappeared i've left switched on 24/7, connected to both banks. I have a fridge on 24/7, the Eber is on 24/7, laptop is on 24/7, FM radio is on a lot, as are lights (albeit LED). Water is pumped by an electric pump.

Let's take a look at my monitoring gubbins :

Engine battery volts : 13.6
Domestic bank volts : 13.5 (slight difference as i have stuff running)
Mains charger volts : 13.4 (float)
Mains charger amps : 4.0
Solar panel voltage : 30.0
Solar charging volts : 13.4 (float)
Solar charging amp : 0.3

Those figures were taken now, as i'm typing. In the Summer i keep the mains charger off most of the time, the solar panels keep up with most of my use. The engine battery will sit at 13.6v and the domestics will vary a bit, i keep an eye on them and if they look a bit low when the Sun goes down i put the main charger on for a while.

My solar controller software keeps a log for 30 days so i can see where the battery voltages have been and i never see any problems. My domestic batteries are open cell and can be topped up, i have not topped them up since i bought the boat, almost a year ago.

How about some real World, extreme battery bank disparity ?

My van has two heavy duty batteries and a 150a alternator. The nature of use means that sometimes these batteries are charged for 10-12 hours non-stop, sometimes left for days unused, sometimes they get some heavy use without the engine running.

Also on the van is a small jump pack, fitted with a tiny, sealed battery, smaller than most motorcycle batteries. For charging, this is connected to the main van batteries. So, this tiny little battery is connected in parallel to two heavy duty batteries all of which are being charged for up to 12 hours straight via a 150a alternator, if they are not being abused by the electrical stuff on the van, which includes a heavy duty winch.

The van batteries are coming up to four years old, not sure about the jump pack, but it's had a hard life and looks like it will finish falling apart before the battery fails, it still manages to start some good sized diesel engines.
 
If you parallel a flat 55ah battery at say 11.6v with a fully charged 110ah one at say 12.6v you'll get a combined voltage of about 12.25v which may or not be enough to start an engine. So it's not a good idea to parallel batteries up for emergency starting. A 1-2-B switch should enable you to select your best battery for engine srarting which would be better than the seperate switches with a 'combine' one. Provided you have a way of determining the state of charge of each.

You also seem to have got lost.

The idea of having separate switches is so that individual banks can be isolated. The third (emergency) switch parallels the systems at the load terminals of the isolators.
 
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All my controversial "opinions" have been backed up by references to well know manufacturers websites with enough information to keep people busy reading, not posting pointless and malicious answers with absolutely no backup or reference material to suggest that my points are clearly wrong.

Exactly, your opinions are "backed up" by manufacturers sales blurb. Very unbiased, i'm sure.

posting pointless and malicious answers

This is a major problem on these types of threads when the argument gets lost amongst the bulls.1t. I have reported this to the Moderators.

Like when you posted
Iif you work in the industry then you are the reason that I post so much to try and educate poor boat owners who are getting fleeced by ignorant experts like you.
 
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