Shore Power Charger

[TBOT422]

Has anyone upgraded their shore power charger? Our boat is equipped with the Charles 30-amp C-Charger. I'd like to increase charging capacity that I could run off a Honda 2000, so that I could reduce re-charge times while at anchor. On recent 2-week cruise, I estimated that we were consuming somewhere between 100 to 150 amp-hours per day (mostly the fridge), and needed to run the engine or the Honda somewhere between 3 to 4 hours per day to keep the batteries charged.

I'm not sure if this calculation is correct, but the math seems to work out: Since we were consuming 100-150 amp-hours of capacity, we need to run the engine (w/ 50 amp alternator) 2.5 to 3 hours or the Honda powering the 30-amp C-Charger over 4 hours. While cruising, it's not unreasonable to run the engine 3 hours per day entering and leaving anchorages, motor sailing, etc. But while at anchor, I'd rather spend my time other than sitting on the boat listening to the generator run.

Thanks

[R.B.]

Unfortunately increasing your battery charger size will not give you the 1:1 boost or increase in charging time that you may be looking for since batteries charge on a curve. Here is a good article on battery chargers: http://www.pbase.com/mainecruising/inst ... ry_charger

A good tool to use is a battery monitor. I have the Victron 600 installed. It will tell you what condition your battery is in, how many amp hours are left, what the charging rate is, what your current usage is, how much you have used etc. For under $200 including wiring etc. you can see what is going on and then adjust accordingly.

[TBOT422]

Ralph,

Interesting article. It pretty much confirms what I suspected. It noted that the charger should be at least 10% of your bank capacity (the Crusing World Feb 2012 article on Batteries suggested 25%). Since I have 3 house banks totaling close to 600 A-H, that would imply a 60-amp charger versus the 30-amp charge that I presently have.

I also got a reply from Charles Industries r.e. re-charge times. They confirmed to me that if I consume 150 A-H of capacity in a 24-hour period, it would take the 30-amp charger 5 hours to fully recover that capacity. Although, as you say, batteries do re-charge on a curve. Charles Industries noted that most of the 150 A-H capacity would be replaced within the first hour even though it would take 5 hours to fully replace. So if you were at anchor for several days and charging with a gen set, you could get away with charging a couple of hours a day. But if you continue to consume 150 A-H/day, the batteries will eventually draw down below a 50% capacity. Replacing the 30-amp charger with a 60-amp charger should cut the re-charge times in half. The ProMariner ProNautic 1260 60-amp unit appears to be able to run from the Honda 2000 as it draws less than 11 amp input.

A battery monitor may also be a good addition, but I think I have a pretty good idea of how much power I am consuming and simply monitoring the voltage of each battery bank gives you a good rule of thumb as to the batteries charge state.

This is nothing I plan to do soon, as it isn't often that I take an extended cruise and spend several days at anchor. But something to add to my upgrade list.

[wolfe10]

Gary,

The answer you got from Charles is incorrect. As any knowledgeable article on charging will tell you, battery charge rate is VOLTAGE controlled. Said another way, a XX amp charger will only put out XX amps until charge voltage reaches the set voltage (bulk rate voltage for smart converters). So 30 amps time 5 hours is NOT 150 amp into the batteries. Maybe 100.

Best use of a battery while on the hook is to charge to 85%, discharge to 50%, recharge to 85%... Once a week run the converter or engine long enough to bring the batteries to full charge.

Also, kind of battery will determine the ideal charge rate. AGM batteries (we have always used Lifelines) allow for a much higher charge rate than wet cell because of reduced internal resistance. So a higher amp charge rate will be of more value if you have AGM batteries.

Brett

[R.B.]

Since you mentioned keeping an eye on the voltage for a battery state, here is another article that may interest you:

http://www.pbase.com/mainecruising/batt ... _of_charge

I still maintain that adding a good battery monitor, will give you more peace of mind while out, and maybe let you run your battery charging (whether by motor or generator) more efficiently. Conveniently here is an article on installing one:

http://www.pbase.com/mainecruising/battery_monitor

[TBOT422]

Ralph,

Good articles and possibly something I want to add to my upgrade plans.

Brett,

Wouldn't a 60-amp charger raise the house banks from 50% to 85% faster than a 30-amp charger?

Thanks

[wolfe10]

Gary,

Absolutely, a higher amp charger will speed recharge rate. As would AGM batteries (as compared with wet cell batteries of the same amp-hr capacity).

And, I agree, a good battery monitor system is a definite asset. We use the Xantrex Link 20. That way I can monitor amps into each bank and cease charging (when running motor or genset just for recharging) when the amp rate drops below a reasonable rate.

But, I view 12 VDC system upgrades as a package. We have a high amp alternator with remote programmable regulator for it with sense wire at the house battery bank rather than at the alternator, 2 AGM 4D house batteries plus 1 start battery and the Link 20. If we had a generator, I would upgrade the converter to a smart charger in the 60 amp range.

Brett

[TBOT422]

Brett,

If we had a generator, I would upgrade the converter to a smart charger in the 60 amp range.

Precisely what I am considering. We already have a Honda 2000 that came with the boat. It worked quite well over our trip. Easy to set up and hook up to the shore power outlet. We even ran the microwave with it. The issue was it took a long time to re-charge the battery banks, and it seems clear to me that the limiting issue is the 30-amp charger trying to charge 3 200 A-H battery banks.

For the time being, we are also constrained to the wet-cell banks that are in the boat. I don't feel like scrapping them out until they need to be replaced. So a new charger needs to be a smart charger that can handle other battery types if and when they need replacing. Right now, I am thinking the ProMariner Nautic 1260 and a battery monitor, but need to look into how much re-wiring is required for the higher currents.

If we didn't have the Honda, I might be considering a new high output alternator and external programmable regulator, but those aren't the cards I'm holding. With a bigger charger, the Honda can save on the wear and tear on the diesel being used just to re-charge the batteries.

Thanks

[wolfe10]

Gary,

Yes, you will definitely want to upgrade to large-gauge wire from charger to batteries, but those are short runs.

No point in investing in a quality charger and then loosing power through too-small gauge wire. Basically, the largest gauge that will install at the charger would determine what gauge I would use.

Brett

[saileagleswings]

Before installing a higher power charger, check the specifications for air space required around the charger. The higher power charger will generate more heat than the 30 amp Charles Charger so it will need more cooling. Also, you will to replace the fuses with higher capacity fuses or circuit breakers and maybe increase the wire size from the charger to the battery bank.

Another option is to add a solar panel. Run the charger using your generator to bring the battery up on the charge curve early in the day to let's say a point where it is accepting only 10 amps or so and then let the sun take over.

[jking]

A question about your honda generator, is it possible to use both the DC outlet on the generator at the same time as the AC outlet? That may give you an extra 8 amps, but you probably keep the gen off the boat to keep things quiet, and just want one cable.

Also while considering chargers you might want to look at some solar inverters as the frequently have built in high capacity efficient chargers, such as Xantrex and Outback which are optimized for use with generators.

J King
#303

[Triumph]

Gary, I've been out cruising for three months and just returning. Sorry for the delayed response. I think I understand your question.

I installed a Heart 2500 charger inverter underneath my nav station. This charger is capable of putting in 130 amps with 30 amp shore power. With the Honda 2000, you have to tell the Link 2000 battery monitor/controller that you only have a 20 amp source (the Honda) . When you do this, the Heart charger limits the input to about 90 amps going in. I have a 450 amp hour battery bank, wet 6 volts, and this can really give your battery bank the fast charge initially. I've seen 87 amps going in, which, over the hour we might run it, will begin to drop down. But I like this system for a quick high output charge source.

My 350, TRIUMPH is equipped with 240 watts of solar, a wind generator, and the Honda 2000. We don't often get low on power, but if we slip behind, this set up gives me a big hit in 30 minutes time..

Bill in Tampa
s/v TRIUMPH