Battery inverter question please-gctid385547

[Guest]

I hope someone can help here. I have a Bayliner Ciera 2655 and have an inverter hooked up to a seperate deep cell battery that is hooked up to a battery charger and is being charged only when on shore power. The battery is fairly new and seems to drain quite quickly.

My question is can I or should I hook this battery up like the house and start battery which also gets charged through the alternator when the boat is running?

Thanks,

Dave

[JimMc]

Dave

In general terms inverters are typically powered from a large house battery bank. The house bank charged from the alternator, shore power battery charger or possibly even a generator.

Keep in mind in terms of energy there is no free ride. As an example say you have a 1200 watt hairdryer. To get 1200w from 120Vac you draw 10Amps. 120V x 10A = 1200W

Now to convert 12V to 1200W you need 100Amps. 12V x 100A = 1200W

In addition there will be some level of inefficiancy. Figure about a 10% loss within the inverter. So you need an extra 10% so now 100A bumps up to 110A.

Now think about the AmpHour rating of your battery/s. If you have a 100AmpHour battery you don't want to draw it below 50% of it's rating if the battery/s are lead acid type. So that battery bank is really capable of reproducably delivering 50AmpHour.

So how many Watts are you drawing from the inverter? That will allow you to calculate Amps.

How long do you want to draw those Watts ? That allows you to then calculate Amp Hours.

[2850Bounty]

First, Jim's answer is dead on!

Davevall wrote:
My question is can I or should I hook this battery up like the house and start battery which also gets charged through the alternator when the boat is running?

Dave, short answer, yes! But there is more to this.

My take is that all batteries within a HLBB (house load battery bank) should be of like chemistry, type, size, age, etc.

If this meets that criteria, then sure..... bring it over and include it in with your HLBB.

Otherwise, you'd be better off to bring in new like chemistry, type, size, age, etc. batteries, and create yourself a larger HLBB.

If you plan to use the inverter with any heavy demands, and want to know your HLBB status, consider one of the battery monitoring systems, such as Xantrex's LINK, or one of the other makers.

These systems monitor your bank in Amp Hours, of which is the more meaningful means of battery monitoring.

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