Newbie ; Have many stupid questions to ask

[showem]

I traded in my Seadoo Sporster 4tec for a Stingray 225 CR Cuddy

1. I have a digital depth gauge will that work when the key is in acc or does the engine need to be running?

2. I have dual batteries,when the boat is running can you charge/alternator both batteries at the same time. I know the selector switch batt 1 is for starting the boat and batt 2 is for accesories for when the boat is anchored.

Thats it now,thanks in advance

 

[tazrig]

Re: Newbie ; Have many stupid questions to ask

:welcome: First off the only stupid question is the one you don't ask.

1) The engine should not need to run to operate the depth gauge. Turn the key to the click just before it starts to crank the engine. Assuming it's wired correctly it should supply power to anything hooked up to the ignition switch. If you don't have power to your depth gauge after doing that, look at your power switches on your dash to see if there is a dedicated power switch for the gauge.

2) By what you described the answer is no. You can flip the switch to batt 1 and charge batt 1 or flip it to batt 2 and charge batt 2 but not both. That being said you can replace the switch you have with one like this that will allow you to charge either or both batteries at once.

Ignition Protected Battery Selector Switch without Key Lock - Perko 8501DP - iboats

 

[Bob_VT]

Re: Newbie ; Have many stupid questions to ask

Make sure if you add the switch to wire the batteries up like this http://forums.iboats.com/electrical...tors/need-info-adding-2nd-battery-249593.html

Welcome to iboats!

 

[NYBo]

Re: Newbie ; Have many stupid questions to ask

Welcome to iboats!:welcome:

1. A definite "maybe." It could be wired to work independently of the ignition or when the ignition is on or in the accessory position. Frankly, there are some good reasons to have it completely independent of the ignition. But you'll have to try it out to see how yoursis wired.

2. As noted, if the battery switch has a "both" position, that will charge both batteries when the motor is running, assuming everyting is wired properly.

 

[pikefisherman]

Re: Newbie ; Have many stupid questions to ask

If a set up is like this and your battery for running the radio is lets say 3/4 depleted, how long will it take to recharge using the motor? I would think quite a while, right?

 

[Bondo]

Re: Newbie ; Have many stupid questions to ask

If a set up is like this and your battery for running the radio is lets say 3/4 depleted, how long will it take to recharge using the motor? I would think quite a while, right?

Ayuh,... It depends on the alternator's output, 'n the batteries,....

 

[chris.olson]

Re: Newbie ; Have many stupid questions to ask

2. I have dual batteries,when the boat is running can you charge/alternator both batteries at the same time. I know the selector switch batt 1 is for starting the boat and batt 2 is for accesories for when the boat is anchored.

I would think that that Batt 1 is a starting battery and Batt 2 for accessories is more than likely a deep cycle battery. Alternators can usually help prevent deep discharge of a deep cycle, but can't charge one properly because the alternator is usually regulated at around 14.0 volts. The purpose of the battery selector is usually to parallel the banks for emergency starting of the propulsion engines in the event your starting battery goes flat. Otherwise the two banks should always remain separate, as they have different charging requirements. Starting batteries are absorbed at 2.40 VPC. Flooded deep cycles are typically absorbed at 2.50 VPC for lead/antimony grid, and 2.58 VPC for lead/calcium grid.

 

[Silvertip]

Re: Newbie ; Have many stupid questions to ask

There is really no reason to run on the BOTH position. The house battery (typically BAT #2) will almost always be the battery that is drawn down the most provided the battery switch is set to BAT 2 when the engine is not running. If that's the case, then you want that battery charged quickly. Leave the switch on BAT 2, start the engine and let the engine charge it. If the battery is depleted to the point where it won't start the engine, switch to BAT 1, start the engine and then switch back to BAT 2. Why not use BOTH in that scenario? Well, you already know BAT 2 won't start the engine so it makes no sense to use the BOTH setting. The starting battery is rarely deeply discharged so again, BOTH is not the best setting. You want maximum "available" alternator capacity going to the battery that is most deeply discharged. If you select BOTH, that "available" output gets shared between the two. Use the switch wisely -- it doesn't take much thought to figure out when or why to use which setting.

As to how long it takes to charge a battery -- that depends on the size (capacity) of the battery, how depleted it is, and the "available" capacity of the charging system. This is just one scenario: You anchor on a sand bar and run ONLY the stereo for two hours. This stereo has an amp and just for illustration, let's say that system draws 10 amps. So in two hours you pulled 20 amps from the battery. You have an outboard engine with a 20 amp charging system. That means you would need to run wide open for an hour to even get close to fully charging that battery. From that you should bet an idea that batteries are buckets of electricity. What you take out must be replaced. How fast it can be replaced depends on the source. How much you take out of the bucket depends on how much current each accessory draws.

 

[chris.olson]

Re: Newbie ; Have many stupid questions to ask

So in two hours you pulled 20 amps from the battery. You have an outboard engine with a 20 amp charging system. That means you would need to run wide open for an hour to even get close to fully charging that battery.

Batteries are not 100% efficient in charging. They go thru basically two stages to reach 100% SOC - bulk and absorption. The bulk stage is usually recommended to be no more than C/10 at the battery's 20hr rate. And the absorption stage is a constant voltage stage. The bulk stage gets the battery to around 80% SOC and the losses are very low - about 5-8%. The absorption stage holds the battery at recommended voltage until the current to the battery drops below 2% C - or some chargers have a timer. The absorption stage is quite inefficient, requiring as much as 150% of the amp-hours into the battery from 90-100% SOC that you get back out on discharge.

So in reality, if you discharge 20 amp-hours out of a 125ah battery you are dealing with the top 15% portion of its capacity, which is the most inefficient stage of its charging. So you can figure it will take 30 amp-hours to recharge it with 20 amp-hours used from it.

I have never seen an engine driven alternator that is capable of properly charging a deep cycle battery. That is best done with shore power or the onboard generator and inverter/charger. But from the newbie's standpoint, I would recommend against placing the battery bank selector switch in the "both" position to charge the house battery from the propulsion engine's alternator. There is too much chance of forgetting it and drawing both your house and starting batteries down to the point where you can't get propulsion engines started. That switch is for emergency use to provide redundancy for house power and propulsion engine starting in the event one bank goes dead. I'm used to working with twin 880ah 24V banks of Surrettes, but the principles are the same for smaller cabin cruisers or cuddy cabin boats where you might get anchorage someplace and stay a night on the water without shore power.