battery Dual switch

[northeast1]

Quick question, how does everyone with duel battery's use the switch?

Ours is the standard switch i.e battery 1, battery 2, both or off, on Stingray i have a separate hook up for the electronics and engine but on On-A-Roll it is fitted with two crank battery's, the circut does not have a relay switch built in so i am guessing both will be charging all the time if set to both.

The electronics side of boating is my weak point by a mile, so always interested to see how people run their boats.

Below is the one i have.....

[Norman]

Yeah Rich I got similar, I have No 1 connecting battery 1 to engine and radio

with number 2 simply connecting the second (services battery) to engine instead of No 1,
All services are hard wired to second battery No 2 so the condition is
1. All services are running from battery 2 with engine and radio on battery 1 (being charged)
2. Everything on battery 2 and charging battery 2
ALL. Both batteries connected and both being charged.

Reasons behind this are I keep battery 2 connected all the time when not aboard which goes up and down in charge.(leaving no drainage on 1.)
I check 1 often by starting Engine but it's main use is as a backup and to power radio seperate from No 2.

Usually give No 1 a bit charge for an hour or two per trip just to keep it fresh.

I NEVER use all, its an emergency as the lesser battery will pull down the better if connected and also puts a bit more strain on alternator.

Hope this makes sense

norm

[northeast1]

Cheers Norman, do you never get any voltage drops resulting in gps or other equipment going off when drifting many times over a mark and only moving short distances? i had Stingray wired up different to this new boat but i am holding off changing much on the electrics side as the boat runs everything from a canbus system.

i have purchased a new battery for the boat as battery number 1 just incase but with no relay switch i was unsure about how to run the two and if it would over charge one or cause gps etc to go off if only running on 1 battery. As i say its all wired in a cabus system and all the wires go through this...it would be a big job to hard wire the electronics to battery number 2. I think i may have to run the boat with switch set to all, most or all of the time???

[Safetyman]

There is a lot online about this topic with some insisting that one battery should be for the engine and one for auxiliaries. Personally I run mine on both all of the time as it is the engine starting (especially when drifting over wrecks) which takes the current and two batteries in parallel are better than one in supplying the power to the starter motor.

The down side is that if they both go flat together.............

[Micky_C]

Me and graham have a similar setup to you and we do get the occasional voltage drop resulting in the gps etc going off. It can be annoying at times. Doesn't always coincide with a long days fishing.

We generally steam out on 'both' then switch to either 1 or 2 and leave it like that for the rest of the day. Always leaving the other battery to start the main engine. If it's a decent steam back we might set them to both again to charge.

I check the batteries regularly and they always appear fully charged.

As an early warning system I always set the voltage alarms on the gps and fish finder as well to say 10/11 volts so if the voltage is low it lets you know as soon as you turn the units on. This can be handy to detect a problem early!

I guess everyone has their own way of doing things!!

Michael.

[Norman]

Me and graham have a similar setup to you and we do get the occasional voltage drop resulting in the gps etc going off. It can be annoying at times. Doesn't always coincide with a long days fishing.

We generally steam out on 'both' then switch to either 1 or 2 and leave it like that for the rest of the day. Always leaving the other battery to start the main engine. If it's a decent steam back we might set them to both again to charge.

I check the batteries regularly and they always appear fully charged.

As an early warning system I always set the voltage alarms on the gps and fish finder as well to say 10/11 volts so if the voltage is low it lets you know as soon as you turn the units on. This can be handy to detect a problem early!

I guess everyone has their own way of doing things!!

Michael.

Aye Micky, similar just I don't like to parallel the batteries (except if ever in emergency) so I steam back half way on one then switch over to half way on the other.

great talk this well done rich, feels like season is approaching .....
what a great time of year ... except for marina fees end of march that is

norm

norm

[Kev1n]

I’ve set my two batteries up slightly differently to the others.

No1 battery is engine start only
No2 only runs the electronics.

When the engine is off a Voltage Sensitive Relay automatically separates the two batteries so the electronics could run and run until they flatten their battery and still not affect the engine battery. Also, when starting the engine using its own battery no1 the electronics are unaffected as they run on battery no2 so no voltage drop.

As soon as the engine is on and the alternator pumps out electricity, the VSR sends charge to both batteries to charge them up.

If there is a problem with either battery I can still use the 1-2-both battery selector to send current to start the engine.

It’s pretty simple to set up. The other option is to use a split charge diode system which gives even better separation but this one causes a drop in the charging voltage that reaches the batteries so slows their charge rate.

Give me a shout if you want more detail; I also bought a hydraulic crimper to fit lugs to battery cables which you’re welcome to borrow if making up new wiring.

PS the new boat looks canny, even the mooring lines match.

[northeast1]

Yer has turned into a interesting thread and alot of ways of setting it up. Kev you have the same set up i used to have on Stingray, CPQ seems to have the set up i have now.

Yer i have spent abit of money on a few things Kev, me and my dad been working on adding a few things since we got it to put our touch on her

[drifter]

Obviously it is essential to have a fully charged battery always available to start the engine. When utilising a 2 battery setup (in parallel) there is still a potential for the GPS, sonar, deckwash etc to run down the batteries when the boat is stationary or drifting with the engine off.
If a "Durite" split charge relay is fitted between the batteries with No 2 battry running the electrics, both batteries will charge up when the engine is running but as soon as the engine has stopped the relay will isolate No 2 battery and No 1 battery will retain it's charge for engine starting.
When the engine starts the split charge relay will allow charge to both batteries and so the cycle continues. This setup will also prevent the start up voltage drop which often trips the GPS/sonar, especially Garmins which are very sensitive. The Durite split charge relays are approx Ł36, they are very un-complicated and very easy to fit.

[big_sean]

Hi Richie

On my old boat I had the same switch but now I have vsr and a blue sea switch as it takes me away from it. I would of used a split charge diode with the blue sea switch but that was not compatible with my engine but with yours it would be.

See here automatic charging relay and a blue sea switch you cant go wrong with this.

SI-ACR Automatic Charging Relay - 12/24V DC 120A - Blue Sea Systems

Sean

[northeast1]

Give me a shout if you want more detail; I also bought a hydraulic crimper to fit lugs to battery cables which you’re welcome to borrow if making up new wiring.

PS the new boat looks canny, even the mooring lines match. [/QUOTE]


I will take you up on that offer of the crimper Kev, would be great as i had planned on doing a few things in the bilge that it would good for. Let me know when your next down the boat or you could put it in the back locker on the boat, it is not locked as has nothing in yet.

[Kev1n]

No bother Richy, I should be down on Sat morning and can leave it in your locker then, and might even get out fishing after, if the weather behaves itself. There’s the hydraulic crimper for the heavy cables and a ratchet crimper for the thinner wires.

[big_sean]

Richy if you are going to fit a split charge system beware on using a VSR as they do have a possible fault although rare it can happen

the problem with a split charge relay is in the unlikely event of one the batteries going short circuit while running it will also flatten the other battery so when you switch of you wont start again. its unlikely but def possible. With the diode system they are always separate even when running so very fail safe. .There is a volt drop but just use good batteries and it wont be a problem

I have to use a vsr on my boat because of the engine but if I had a different engine I would use a split charge diode.

Sean

[northeast1]

We have decided to go for a relay switch, bit more expensive but will do the job required, once fitted it will mean she only needs a lift out and anti-foul then ready for the season.

[Whaler]

I think you have made the correct choice.
The acr when correctly fitted (unfortunately not in my case) has to be the best fit and forget option.
It's like having the mechanical switch you used to have but with a processor making the simple but intelligent decisions on when to flip the switch (connect or disconnect the two battery banks).

Recently spent some time sorting my own system, the original builder had fitted an undersized acr ( rated lower than the alternator output) and the interconnect cables were also undersized resulting in a near fry up...
Just note the acr needs to have properly rated cables connecting it up, which in my case required 50mm2 cables!