Starter battery

[Fishpants]

Can someone tell me how to access the starter battery on my 2016 29S? Can’t believe I don’t know this...
I’m currently stuck and waiting for a jump, as somehow my starter battery died. No idea how, as I though it was supposed to be isolated!
Anyway, once they come, I’ll have to access the starter battery, and as I said, I don’t see it!
(I clearly have some exploring to do...)

 

[Andrew Custis]

I believe you have to remove the other batteries to access. Did you switch the parallel on and use your house batteries to start?

 

[Fishpants]

Hi Andrew,
Thanks for the quick reply. I just spoke to Dave Turner from Port Boathouse who walked me through a few things. Yes, batteries were on parallel. Both house and starters were below 12v this morning. Dave figured I must have left selector on parallel over night, which is possible, but i’m pretty consistent with my start procedure, and always turn parallel off once started. I have noticed that if I try to start without parallel on, it won’t even turn over, which leads me rob believes will have a starter battery issue. I’ll have to explore that a bit further.

 

[captstu]

Flashpants, On my 200 R-25, all four batteries are in parallel "most" of the time - independent of the switch settings.

My boat was factory wired (and correctly reflects the wiring diagram) to automatically connect with two ACR (Automatic Charge Relays): 1) house and thruster + 2) house and starter. This way, the single power source from the engine alternator will charge all three banks - as will the solar cells that are, on my R-25, connected only to the house.

The factory battery charger is connected to all three batteries - each isolated with a diode that lets the respective battery charge without permitting draining should one battery get low.

I am unable to determine what the "house" and "engine" and "emergency" switch do on my R-25 - disconnecting or shorting them has no apparent effect, but with the Automatic Charge Relay (ACR) in place, there should be no effect.

All is good normally. But, if the STARTER battery is weak, for some reason, the ACR will automatically disconnect it from the House battery preserve what power you have. When mine aged, everything worked until I shut down overnight. At that point, the STARTER battery drained from age and the HOUSE battery drained from load. The "emergency" switch does nothing on my boat, but bridging the ACR immediately started the engine. You need only about 12 GA wire for the bridge - that is enough to turn on the ACR and transfer power to start the engine.

West Marine sells a perfect switch for this: COLE HERSEE M-608 Moisture-Sealed Switch
https://www.westmarine.com/buy/cole-her ... cordNum=19

Wire this across the two heavy terminals on the ACR - it will cause the ACR to turn on so you can start the engine. Just push the button for 10 seconds or so - assuming your solar cells are working - and the STARTER will come back online.

 

[knotflying]

Stuart,

Something does not seem right with what you said. The ACR is supposed to isolate a bad battery when a battery drops below 9.5V . So if your engine battery went dead the ACR should have opened and prevented it from draining the house bank. It may be possible that you have a defective ACR or something is funky with the wiring.

 

[captstu]

Knot, The ACR does exactly as you say.

According to Blue Sea:

"his relay will protect your sensitive electronics by temporarily isolating the house loads from the engine circuit during engine cranking.

The Blue Sea Systems Starting Isolation Automatic Charging Relay automatically combines battery banks during the charging cycle and isolates them while discharging, plus protects sensitive electronics by temporary isolation of house loads from engine circuit during engine cranking. "

Here is the catch.

On my Charge Battery ACR, the open voltage is about 11.8 measured with my digital VOM. At this setting, the batteries are already quite drained. When the solar cells begin charging the house bank, the ACR still thinks the charging battery is "dead"" and doesn't start charging again. When I bridge the ACR out, the voltage on the Charging Battery side rises ad the ACR cuts on, charging the Starting Battery so the main engine will start. I thought this was correct, but it doesn't agree with the spec:

"Relay Contact Position
Combine (30 sec.) 13.6 Volts 27.2 Volts
(2 min.) 13.0 Volts 26.0 Volts
Open (10 sec.) 12.35 Volts 24.7 Volts
(30 sec.) 12.75 Volts 25.5 Volts
Open High 16.0 Volts 30.0 Volts"

According to this, when the voltage on one side reaches 13.6 volts for 30 seconds the bank should combine unless the voltage when combined is below 12.35 volts.

So, I guess mine is not working according to the spec.

Sorry for the confusion.

I don't know why bridging is working on my bank. I'll keep looking.

 

[knotflying]

I think I understand you and if I do it sounds like it is working correctly. If the starter battery is discharged the ACR will not close and allow charging because it assumes something is wrong with the battery. When you "bridge" it you are actually bypassing the relay and then a charge is going into the battery. If it is enough of a surface charge and you disconnect the "bridge" then the ACR will detect that there is enough voltage to close and hence the start battery will be getting a charge. Also, doesn't your solar setup allow for either a 50/50 charge between the house and starter or a 10/90? This is important since even though your ACR is open there may be a charge from the solar on the starter.

Also there is an older ACR - SI-ACR Automatic Charging Relay - 12/24V DC 120A Which you may have and the functions at various voltages are somewhat different than the newer one.

Blue Seas tech support is pretty good. You may want to call them and see what they say.