Battery Charging Questions.

[Hud3]

Originally Posted by Duke 48

...but I am trying to predict what it will take to keep the wife satisified after we have been aboard for a while...

You are a truly wise man!!!

[Duke 48]

Westwind,
For now, I am looking at the AGM batteries because of the very tight space requirements. Right now, I have only two standard batteries, and they satisify our needs with no problem. I will be installing three batteries where I now have two, and an inch here and a half inch there is making a big difference. Plus, if AGM batteries are trully maintenance free, it will be a benifit because the battery compartment will be less accessable. You are right, a good marine battery charger is not cheap, and I will be investing in a good MTTP controler before money goes toward a charger.

[Duke 48]

Originally Posted by Adelie

In summary:
Get a small panel to maintain the starting battery.
Get an MPPT controller for the solar panels.

Cruising away from the developed world:
Get flooded batteries.
Get a jug of distilled water and a good battery density meter
Make sure you have some means of doing an equalization.

Cruising the developed world:
Get whatever batteries suit your fancy
Make sure your controller will deliver the appropriate voltages for the type of battery you have chosen.

Wait and see how you actually use the boat before investing in a charger that may see little use.

-Currently, we do not have pans to travel away form developed countries.
-Using an extra solar panel dedicated for the starting battery is something I had not thought of. If I can find the space I will give it a try.

Your suggestions, and those made by the others who have responded to this thread, have been a big help in clearing the waters. Many thanks to all.

[Adelie]

Originally Posted by Duke 48

-Currently, we do not have pans to travel away form developed countries.
-Using an extra solar panel dedicated for the starting battery is something I had not thought of. If I can find the space I will give it a try.

Your suggestions, and those made by the others who have responded to this thread, have been a big help in clearing the waters. Many thanks to all.

Shouldn't be too hard to find space, these are of a size that you can prop up in a porthole and forget. Here's an example: http://www.amazon.com/Wagan-2017-Sol.../dp/B000VHT9GS

[Duke 48]

Adelie,
Thanks for the suggestion. It looks like one or maybe two would do the job.

[Pete the Cat]

Have no idea why folks carry a separate starting battery. Never had one in 30 years--with a few years out full time cruising. If you have a bank and run it down, you can always wait for a bit and batteries recover enough to crank. Or use the other bank. I am not sure what adding a generally puny battery for the engine does for your safety or convenience--except to require you buy a lot more gizmos and wiring from your suppliers. I also so not get the reasons for using exotic batteries. Lead acid works--simple cheap. I would see the need for more than a 55A alternator and a three step regulator for sure. And carrying 4X your daily useage in ah.

[Ex-Calif]

Originally Posted by Pete the Cat

Have no idea why folks carry a separate starting battery. Never had one in 30 years--with a few years out full time cruising. If you have a bank and run it down, you can always wait for a bit and batteries recover enough to crank. Or use the other bank. I am not sure what adding a generally puny battery for the engine does for your safety or convenience--except to require you buy a lot more gizmos and wiring from your suppliers. I also so not get the reasons for using exotic batteries. Lead acid works--simple cheap. I would see the need for more than a 55A alternator and a three step regulator for sure. And carrying 4X your daily useage in ah.

Not sure I understand. You say, "...use the other bank..."

The start battery is the other bank. Most boats I see gang all the house bank in one (max a/h available) and have a single battery second bank for starting and perhaps running the windlass.

Did I misunderstand your suggestion?

[Exile]

Originally Posted by Pete the Cat

Have no idea why folks carry a separate starting battery. Never had one in 30 years--with a few years out full time cruising. If you have a bank and run it down, you can always wait for a bit and batteries recover enough to crank. Or use the other bank. I am not sure what adding a generally puny battery for the engine does for your safety or convenience--except to require you buy a lot more gizmos and wiring from your suppliers. I also so not get the reasons for using exotic batteries. Lead acid works--simple cheap. I would see the need for more than a 55A alternator and a three step regulator for sure. And carrying 4X your daily useage in ah.

Interesting & rather refreshing take on this. I'm inclined to make some changes towards this general direction but not entirely. When I bought my boat it was already configured with 3 separate banks: House-2 8D's; Eng Start-1 8D(!); Genset Start-1 G24. For better or worse, all 3 banks are now LifeLine AGM's in the exact same configuration as the PO had. Since the 8D for eng starting seems like a waste, I'd like to tie it in to the house bank. With 3 8D's for a house bank, I'd then have 675ah. The boat also has solenoid relays that can call in the house bank for both gen & eng starting if need be.

Questions:

1. Is the G24 AGM batt enough to start my 80hp Westerbeke engine? The eng manual states that 4-600 cca are needed, an amt. that is exceeded by the G24 according to the LifeLine website. It just seems awfully small to me, but I have the house bank available if need be via relay.

2. The engine has 2 50 amp alts. that charge the eng & house banks separately. (The G24 for starting the genset is charged off the eng batt via a BEP VSR device). If I wired the eng batt into the house bank, bought a Balmar 612-Dual regulator device for the 2 alts., would I not then have 100 amps worth of alts charging the new, 3 batt house bank? Is there a downside I am overlooking?

There are 3 separate, individual switches for each of the banks that are for consumption & checking meter voltage only. The alts (& 110v batt charger) charge the batts independently of these switches. The eng start & gen have simple on-off switches, whereas the house bank has a 1-2-All-Off (I always leave it in the All position).

After reading so many battery/charging threads, I'm amazed there are so many variations on 12-volt systems. In any event, I think it may be feasible for me to undertake this rewiring project myself w/o a lot of expense and better utilize the boat's substantial battery & charging capacity. I'm not sure I entirely agree with Pete the Cat's approach to dispensing with a separate start batt altogether, but I definitely cannot understand the utility of a dedicated 8D start batt for a 80hp diesel engine.

I'd be much obliged for any assistance, guidance, thoughts, etc.

Thanks,
Dan

[Exile]

Originally Posted by Ex-Calif

Not sure I understand. You say, "...use the other bank..."

The start battery is the other bank. Most boats I see gang all the house bank in one (max a/h available) and have a single battery second bank for starting and perhaps running the windlass.

Did I misunderstand your suggestion?

I've heard of some people splitting their house banks in the event something goes wrong with their charging system, etc., they can resort to the other, unused bank. Beth & Evans talk about doing this, but only on long passages. I would assume this is what the poster meant since he disavows the use of separate starting banks.

[Ex-Calif]

Originally Posted by Exile

I've heard of some people splitting their house banks in the event something goes wrong with their charging system, etc., they can resort to the other, unused bank. Beth & Evans talk about doing this, but only on long passages. I would assume this is what the poster meant since he disavows the use of separate starting banks.

I have 3 AGMs split 2 and 1. I consistently run them paralled. The only time I isolate is when I am on the hook in case we drain the well we can start.

I can see splitting the house with big systems.

Not sure the complexity of 3 banks would be worth it. Seems confusing and too much fiddling around, but there are lots of folks who like fiddling...

[Exile]

Originally Posted by Ex-Calif

I have 3 AGMs split 2 and 1. I consistently run them paralled. The only time I isolate is when I am on the hook in case we drain the well we can start.

I can see splitting the house with big systems.

Not sure the complexity of 3 banks would be worth it. Seems confusing and too much fiddling around, but there are lots of folks who like fiddling...

Do I understand this to mean that you also are in favor of not having a separate start batt? I.e., you just have one house bank comprised of 3 batts which you can either use together or split to keep a reserve offline? This might be a simpler solution for me with my 3 8D AGM's. That way I could ditch the G24 gen start batt/bank & its echo charger too.

Fiddling around is OK if it results in less fiddling, no?

[Ex-Calif]

Originally Posted by Exile

Do I understand this to mean that you also are in favor of not having a separate start batt? I.e., you just have one house bank comprised of 3 batts which you can either use together or split to keep a reserve offline? This might be a simpler solution for me with my 3 8D AGM's. That way I could ditch the G24 gen start batt/bank & its echo charger too.

Fiddling around is OK if it results in less fiddling, no?

Sorry to be unclear. My bank is split 2 house, 1 "start" but I run the switch in the all position almost all the time. It is only when we anchor out overnight I switch and isolate the start battery (off). This way in the morning if the house is low/dead I can still start.

My boats and its needs are very simple - not in the class of 90% of the folks here.. Once we start after a weekend out we run the engine an hour or 2 motor sailing to charge things up in a "hurry." Most weekends of daysailing my "tiny-topper-upper" solar takes care of replenishment of the otto, music and instrument drains during the week while I am away. The additional drains when overnighting for me include cabin, anchoring and nav lights, dvd player, phone, computer, ipad charging

[Exile]

Originally Posted by Ex-Calif

Sorry to be unclear. My bank is split 2 house, 1 "start" but I run the switch in the all position almost all the time. It is only when we anchor out overnight I switch and isolate the start battery (off). This way in the morning if the house is low/dead I can still start.

My boats and its needs are very simple - not in the class of 90% of the folks here.. Once we start after a weekend out we run the engine an hour or 2 motor sailing to charge things up in a "hurry." Most weekends of daysailing my "tiny-topper-upper" solar takes care of replenishment of the otto, music and instrument drains during the week while I am away. The additional drains when overnighting for me include cabin, anchoring and nav lights, dvd player, phone, computer, ipad charging

OK, got it -- thanks. I suppose the only downside is that the 2 house batts will pull the presumably less stressed start batt down to their level when all 3 are paralleled. If there's a dedicated start batt used only for starting the engine, it's likely to stay healthier since it's generally topped off. As always, pros & cons must be balanced . . . . I still think my 8D for eng starting is overkill & wasteful, but I rarely worry about being able to start my engine!

[Adelie]

Originally Posted by Exile

Questions:

1. Is the G24 AGM batt enough to start my 80hp Westerbeke engine? The eng manual states that 4-600 cca are needed, an amt. that is exceeded by the G24 according to the LifeLine website. It just seems awfully small to me, but I have the house bank available if need be via relay.

A group 24 can start a a 125-150hp gas car engine regularly. Gas engines draw less than diesel when starting but not that much less. I wouldn't worry about it if the rating works.

Three banks seems to me like you are begging for an argument with Murphy.

[noelex 77]

Originally Posted by Adelie

Battery choice:

If you are going cruising away from developed countries, get flooded batteries, you don't want to mix and match and gels and AGM's are not very available in developing places.

My understanding is that gels and AGM's do not have the life expectancy of flooded and they are more expensive. .

I would advise the opposite. AGM and gelled batteries have a longer life, but at a greater cost. If you are are crusing developed areas flooded batteries are usually the cheapest option, but if you need to replace the batteries in underdeveloped areas the cost is much higher. Transport costs are a significant part, batteries are very heavy and flooded (but not AGM and Gel) batteries are classified as hazardous goods. The longer life of AGM or gel can make them cheaper than replacing them in underdeveloped countries.
Having your house battery bank set up so it is possible to separate them into 2 banks ( giving 3 banks including the start batteries) is helpful when crusing any areas where deep cycle batteries are difficult to get. If batteries fail you can pick the best old batteries to form one bank. In underdeloped countries it is very difficult to get deep cycle batteries at short notice, but car start batteries can be got anywhere. This can form a cheap second bank. This combination will last untill you can get somewhere where deep cycle batteries are cheap, or at east available.
Even better if when leaving on your voyage if you replace half the batteries with new ones, the two house banks will be different ages, which makes sudden complete house battery failure unlikely.

I think a completely separate start battery that is used only for starting ( or possibly the anchor winch as well) is good insurance.