Battery Switch

[bay_firey]

G'day All

Quick question, I have a dual battery setup on the Seafarer with an isolation switch

I know one should not turn the switch to off whilst the motor is running but can the switch be changed from say Batt 1 to Both then to Batt 2 whilst the engine is running ???

I was thinking of rewiring and was going to use 1 as a house battery and the other as a starter battery and was wondering if the house battery was getting a bit low if i could just switch between them whilst running to give it a top up ??

[blaze]

yes

[snappa]

wiring as spec. and then yes ...

[Chimo]

Hi bay_firey / Mark

Making your second, preferably, deep cycle battery, a house battery will certainly protect your expensive nav and fish finding gear.

You can also ensure that you can always start you engine after operating at night or running bait pumps etc if you fit an automatic battery coupler between the two.

That way you don't have to worry about manual switching to charge your 2nd battery as the auto battery coupler also reconnects the two batteries after the motor has started and electrical spikes are no longer an issue as well as disconecting to protect the electrics from spikes when you start you motor..

Soon after I bought my Seafarer I noticed I was losing pixcels in my Lowrance Global Map and while the Lowrance guarantee covered a replacement Lowrance urged me to not run nav and other electric from the motor battery any more or at least to have the electrics off when starting motors.

To make a long story shorter, I got a marine electrician to rewire the boat and add a house battery (deep cycle). He also introduced me to the Auto battery Coupler, a cheap bit of gear made on the Gold Coast that takes all the worry out of batteries and instrument management.

It was such a pain to have to turn the GPS and depth finder off every time I started motors.

There a couple of the wire diags for you too

Hope this is of some help

Chimo (ex firey) GOM

[Chimo]

ABC details

[timddo]

chimo, how much are the couplers and where.

[Mr__Bean]

Sounds a bit like the Voltage Sensitive Relay's sold at Bias Boating.

See the item third from the bottom of this page:

http://www.biasboating.com.au/battery_swtch.html

- Darren

[Chimo]

Hi Guys

Mr Bean / Darren

Re yours If the copy below is the item you meant then it is similar BUT NOT the same.. The BEP would be OK for two starting batteries but not for the mix of a starting and a deep cycle that is the House battery. The Auto Battery Coupler does the all that the BEP does but it also disconnects the two in the instant when you turn the key to start the motor and the battery voltage drops below "Xv " .

It does this as the starter motor engages etc and current is drawn down because the ABC senses that soon after this the motor will start and the voltage will be unstable with probable spikes, that are not good for electronics, will likely occur. After the motor has been started and when the voltage flow from the motor is stable the ABC re-opens the circuit and house battery charging can safely continue without risk to electronics.

[i]"BEP Voltage Sensitive Relay Cat. 2330 BIAS $124.90
Relay directs all power into the first battery until it reaches 13.7 volts then closes to charge two batteries together. When engine is stopped, relay opens separating batteries. 100amp/12 volt. Size 69 x 69 x 50mm. [i]

Timddo

I contacted the guy who developed and used to made the ABC about price and availability but he told me he has retired, but wait there is more!

He gave me the details of the guy who may now be producing them and I have left a message seeking details of price and availability. I will post the details asap when he gets back to me later this week. When I bought my ABC some years ago I believe it was not nearly as expensive as the BEP item above.

Later......

Cheers

Chimo

[Payneful]

Chimo

They both work on exactly the same principles. What BIAS forgot to mention is that it disconnects when the voltage of both batteries (since they are connected in parallel) reaches 12.7 volts, so unless you had amazing batteries that had zero internal resistance they would certainly disconnect. Mixing house or starter batteries would be exactly the same with either system.

Using a relay without flyback voltage protection (diode) could lead to nasty voltage spike also. The BEP VSR has this built in, does your system have this protection? Something to check.

Sam

[Chimo]

Hi Payneful

Yes there is spike protection in the ABC; thats one of the main reasons that the marine Elec fitted it to my setup.

You would have to wonder why BIAS / BEP didn't promote this valuable feature that would help to sell their units too, maybe you could chase it up?

If as you say the Bep has it too then thats great, there are two to choose from.

Cheers

Chimo

[capt]

Hey Chimo , did you get my PM ? I'm keen for the ABC number ,OVER........ JIMMY

[bay_firey]

Thanks for the feedback

Answers my question, but I am thinking that a Voltage Sensitive Relay may well be the best way to go