Questions about replacing battery charger

[ADMPRTR]

Thank you everyone for your responses. There is a lot for me to consider.

If I may, I have a couple more questions:

Do I need to be concerned about the number of simultaneous batteries a charger can support? If the two house batteries are connected to each other, would I need a charger that support more than one battery to charge them? It seems to me that I could get a two bank charger: one for the house bank and another for the engine battery. Or just one with a single bank and ensure that that the battery switch is on "Both".

Should I be looking for a digital charger? The one I purchased does not appear to be digital although it is supposed to be fully automatic.

And finally, if I was at some point planning on getting a inverter, is it better to get and inverter/charger or to purchase a separate inverter in the future?

Regards,
Andrew

[Pete7]

The Sterling requires the output terminals be wired together if you are only charging one bank. So keep it simple and keept the batteries wired together, with one HD wire from the charger to the batteries.

The difference a digital charger will make, hmm not sure.

The inverter question, well thats going to put the cost up. Also you would need to work out what you are going to run on the inverter and how much power it will take. A laptop is one thing, although better to supply via 12v, a kettle or toaster is going to need something the size of a small cabinet and lots of dollars. If you have a genny then large mains power should come from that. We run our genny for the pressure wash, hoover or heating.

Pete

[btrayfors]

Originally Posted by ADMPRTR

Thank you everyone for your responses. There is a lot for me to consider.

If I may, I have a couple more questions:

Do I need to be concerned about the number of simultaneous batteries a charger can support? If the two house batteries are connected to each other, would I need a charger that support more than one battery to charge them? It seems to me that I could get a two bank charger: one for the house bank and another for the engine battery. Or just one with a single bank and ensure that that the battery switch is on "Both".

Should I be looking for a digital charger? The one I purchased does not appear to be digital although it is supposed to be fully automatic.

And finally, if I was at some point planning on getting a inverter, is it better to get and inverter/charger or to purchase a separate inverter in the future?

Regards,
Andrew

That's three questions :-)

1. There is no need to buy any charger with more than one output. You simply wire all the house batteries together as a single bank (and leave them that way), and you maintain any secondary battery (like a starting battery) with a voltage follower device like an EchoCharge or DuoCharge, or with an automatic charging relay (ACR). I prefer the first type because it avoids any possibility of high inrush current from a charged battery to a deeply discharged battery.

2. Which one did you purchase? Virtually all modern chargers are multi-stage "smart chargers". "Digital" doesn't mean much; almost all chargers have digital devices controlling their output.

3. There's something to be said for having separate inverters and chargers, as well as something to be said for having a combined unit. Depends on your situation: where you're starting from, what your plans are, how much you want to spend, etc.

Bill

[ADMPRTR]

Thank you everyone. Your assistance is greatly appreciated. Now I have to decide what to do and when to do it.

Best regards,

Andrew

[Slainte40]

Hope this is in the right spot as I am setting up to replace my house bank from 4 6v batt to twin 8d batt and replacing my charger to a xantrex 3000 inverter/ charger in hopes to have enough batt back up for long cruises I do have a northerlights 8k gen but thinking also of adding a wind or solor to this system we are moving onboard soon and starting our life of live abaord and cruising as I read these countless post it seems I keep getting them all twisted and then start over and over again remember I am a ret Marine and I like direct answers lol any other ideas would be of get help thank you all in advance for your help

[ADMPRTR]

Originally Posted by Slainte40

Hope this is in the right spot as I am setting up to replace my house bank from 4 6v batt to twin 8d batt and replacing my charger to a xantrex 3000 inverter/ charger in hopes to have enough batt back up for long cruises I do have a northerlights 8k gen but thinking also of adding a wind or solor to this system we are moving onboard soon and starting our life of live abaord and cruising as I read these countless post it seems I keep getting them all twisted and then start over and over again remember I am a ret Marine and I like direct answers lol any other ideas would be of get help thank you all in advance for your help

First off, welcome aboard! Yes, these threads can become difficult to follow sometimes as more people respond.

I don't have the expertise to respond but I would suggest listing your questions in sequence to make it clear what you are looking for. Also, if this thread so not really on topic for you, feel free to start a new one.

Andrew

[Pete7]

Originally Posted by Slainte40

Hope this is in the right spot as I am setting up to replace my house bank from 4 6v batt to twin 8d batt

Hmm, first thought, can you pick up an 8D battery? I have just replaced a pair of 110 AH batteries and they were heavy enough carrying to the boat via the dinghy. Wouldn't 4 x 105 Trojans be the easier option?

Pete

[Slainte40]

I do agree but yes I can carry the 8d but it is not easy what I am thinking is the 8d from my understanding is the ability to discharge and recharge curve I mean you can drain a 8d all the way down and recharge to full without hurting the life of the battery as I stated before I am not well versed in this tech but am looking for ideas on how I could set my 40' so it could be self contained with minimal running of the gen or the eng most systems run dc a few ac outlets and as for a/c when needed i could run the genset

[btrayfors]

Originally Posted by Slainte40

I do agree but yes I can carry the 8d but it is not easy what I am thinking is the 8d from my understanding is the ability to discharge and recharge curve I mean you can drain a 8d all the way down and recharge to full without hurting the life of the battery as I stated before I am not well versed in this tech but am looking for ideas on how I could set my 40' so it could be self contained with minimal running of the gen or the eng most systems run dc a few ac outlets and as for a/c when needed i could run the genset

Slainte40,

You need to do some more reading. And thinking.

The size of battery, 8D or golf cart or other, has NOTHING to do with the ability to deep cycle and recover without damage. Rather, the battery construction and chemistry type affects these properties.

Stick with the golf carts. The 8-Ds are much too heavy for easy handling, and even if you can wrestle them now a time will soon come when that's no longer possible.

Golf-cart size flooded batteries offer the most bang for the buck. Their robust construction allows for more "deep" discharges, but typically they -- and other flooded types -- should not be discharged below about 50% of capacity. Four golf-cart batteries in series/parallel would give you 450AH total capacity, or about 225AH usable capacity. However, when you're out cruising, you typically only charge to about 80-85%, since to get that last 15-20% charge takes too long and too much energy -- unless you have a hefty solar array or wind generator or both.

To get best efficiency, you need also to pay attention to your onboard mechanical charging capability, meaning the alternator and the battery charger/generator setup. The larger this capacity, the faster and more efficient you can recharge your house batteries.

Bill

[Slainte40]

Thanks and yes I am looking into it more as I have my boat hauled out right now and redoing the bottom and I am going thru all systems and that is where the question came to me thanks again

[lorenzo b]

We use generic auto battery chargers, $60, and have no problems with 6 8D batteries. If you wand the special super duper marine grade charger for three grand, rock out. If you get a generator, make it a diesel so you don't blow yourself out of the water handling gasoline. If you are on a small boat and are careful not to use a lot of electrical power a solar or wind generator can go a long way to supply you with the power you need. Larger boats need a generator.

[djmarchand]

Slainte40:

The advice you have been getting regarding golf cart batteries instead of 8Ds is good. Let me offer some more.

Xantrex inverter/chargers when they were Heart Interface were pretty good. They did what they were advertised to do with low failure rate. Since being bought by Xantrex, things have gone downhill.

Victron and MasterVolt have developed good reputations in the marine industry. Their stuff works, doesn't fail and they have much better customer support. They are more expensive, but quality costs.

[Pete7]

Originally Posted by btrayfors

Slainte40, You need to do some more reading. And thinking. Bill

Slainte, there are a couple of link in posts 19 and 21 I put up, worth having a read. Some folk agree with Charles Sterling, some don't but he makes some good points and I for one have followed his advice on house batteries. He also makes the point about charging and discharging which is repeated on this forum. For longer battery life don't go below 50% discharge.

Pete

[Slainte40]

Thank you all again I did read that link earlier and it made sense but now after further review it seems to make even more sense Thanks again to everyone

[Oldsoul]

The use of 6 volt golf batteries works well for many. As suggested earlier, 4 batteries wired parallel and in series would give you 12 volts and roughly 440 ah which works well for many as their house bank. Your can get these batteries for about $80 each from Sam's club or Costco.

If you really want to design a system that will work best for you, read Nigel Calder's book. The name is something like "electrical and mechanical systems". While it won't answer every question, it will give you quite a bit of info towards figuring out what your needs will be and how to meet them.