Battery Bank with Switch, help?

[chpthril]

Here's how my add a battery is wired (although I don't have SI hooked up either as house and starting loads are all on the same battery anyway):

What are you considering "house" loads, if not the stereo? A "house" load would be anything thats not engine management/navigation IMO. On a tow boat, that would include stereo, accessory lighting (bling'd out LEDs), ballast, etc.

[jbar]

The isolation/combining functions are based solely on battery voltage, not the fact that the engine is running and the alt is charging. If both batteries are above the isolate voltage threshold, they will be combined even with the engine off. So, they banks could already be in combine mode when the starter in engaged. If so, the load of the starter may pull down the house bank low enough to cause some electronics to cycle off and reset. This is a condition where wiring up the SI would be needed. As soon as the starter is engaged, the relay isolates the house from the starting bank.

Thanks Chpthril - I've learned a lot following your posts over the years.

[chpthril]

The isolation/combining functions are based solely on battery voltage, not the fact that the engine is running and the alt is charging. If both batteries are above the isolate voltage threshold, they will be combined even with the engine off. So, they banks could already be in combine mode when the starter in engaged. If so, the load of the starter may pull down the house bank low enough to cause some electronics to cycle off and reset. This is a condition where wiring up the SI would be needed. As soon as the starter is engaged, the relay isolates the house from the starting bank.

(a) why is starter isolation necessary at all (remember it's not present in the one battery solution most boats come with)? and

(b) the blue sea acr only combines above 13.3v, so the "you are still combined" issue really only applies with gel cells, right?

A) hilighted in red

B) Yes, it combines at 13.3, but stays combined until the voltage drops to 12.3V before isolating again.

[shawndoggy]

What are you considering "house" loads, if not the stereo? A "house" load would be anything thats not engine management/navigation IMO. On a tow boat, that would include stereo, accessory lighting (bling'd out LEDs), ballast, etc.

In my case, everything but the stereo. All stereo to one battery (HU, EQ, amps, other perpherals); All other duties to the other battery (starter, heater, gauges, etc etc).

Which wakeboat electronics will reset in your experience to need the SI engaged? I haven't ever used it and it hasn't been an issue.

[Nobody]

What are you considering "house" loads, if not the stereo? A "house" load would be anything thats not engine management/navigation IMO. On a tow boat, that would include stereo, accessory lighting (bling'd out LEDs), ballast, etc.

Wow! That's good advise and grahp. Thank!!

[shawndoggy]

Wow! That's good advise and grahp. Thank!!

lol, no prob. I've hooked it up wrong enough to have to draw a picture.

one key issue is to make sure the batteries and the leads to the acr don't share common posts if you ever want to use a charger. If the battery and the acr are on a common post, when you charge the battery the acr will combine and you'll charge both batteries, even if the switch is turned to off.

[chpthril]

In my case, everything but the stereo. All stereo to one battery (HU, EQ, amps, other perpherals); All other duties to the other battery (starter, heater, gauges, etc etc).

Which wakeboat electronics will reset in your experience to need the SI engaged? I haven't ever used it and it hasn't been an issue.

I agree that anything that functions when the engine runs, would not be a house load: Gauges, heater, shower, ECM, starter, nav lights, plus the auto-bilge wire....it needs to be straight wired and the starting battery is the least likely to ever be rub down. Anything you want to run with the engine off, could go to the house bank. Stereo, fog machine, rotating disco ball, etc.

I dont see anything wrong with your setup, was curious what you had as hose loads, but not wired to the house (stereo in your diag) battery.

Well, it could be seen in any electronic, depending on the state of the batteries. Amps and head-units, SAT receivers could be subject to a low voltage cycle. But as stated earlier in the thread, its not always needed, but its there IF someone does experience equipment cycling off or resetting. On other boats with house loads such as A/C, fridge, hi-tech nav/chart/plotting or weather radar, fish/depth, etc, some of these my not like to be cycle off due to low hose battery level cause by the diesel engine starter pulling a 400A load.

[Nobody]

I bought two of these and hooked them up direct to the batteries so I know what state their in without having to climb inside and turn over the switch. (2 + 6)

[chpthril]

I bought two of these and hooked them up direct to the batteries so I know what state their in without having to climb inside and turn over the switch. (2 + 6)

One and a toggle switch will allow you to see the voltage state of both banks. If your boat has a traditional volt gauge on the helm, you can do the same thing and no need to buy an additional gauge.