Battery Chargers ??? recomendations

[Zane Lewis]

Hi All,
We are looking for a battery charger for our Yacht.
It's the House Battery's which are 2x 12 volt 125amp hr Deep Cycle's. We are in a marina, Putting a 240/50AC cable in would also let us run a lightbulb to help keep her dry and warm inside.

One Crew member uses a CPAC ?? Breathing Machine (for Sleep Aponeia) at night which runs off the AC inverter and as you can guess is hard on the Battery's. Hence we need to ensure the batteries are at their best before we leave.

My research suggests that a 4 stage charger with de-sulphating capacity would be a good thing as after a week or two away the batteriers can get well down.

Any suggestions for brands or experiance etc.
I'm looking at something like this but it's pricy. Expect I can find something at a trade price but still $$$.
http://www.trademe.co.nz/Trade-Me-Motors/Boats-marine/Parts-accessories/Radio-electronics/auction-162421032.htm

Cheer's

Zane

[Salty Sailor]

Also check out the Aus ebay its cheaper... They might post to NZ..

http://cgi.ebay.com.au/Ctek-XS15000-12-volt-8-step-battery-charger-15A_W0QQitemZ230264412818QQihZ013QQcategoryZ33575Q QssPageNameZWDVWQQrdZ1QQcmdZViewItem

I relise you have access to 240 vlts but for a little more money you could get a solar panel and controller. Some contrllers can also take 240vlts for a fast charge but they would most likley be very expensive.. You can then finish the trip and go striaght home instead of waiting for your batteries to charge.

[TMny]

I have no experience with the newer chargers. Last summer [for an acquaintance] i looked into a system using a solar PV-cell array , and a charge-controller ... and found a 'local' (to me) company that makes those and also grid/mains operated chargers; a fellow i spoke with there sails locally (again local to me!). They also offer a design for aviation use incorporating a temp sensor .

With all due respect to the model you selected , i think you may do well with a smaller/cheaper unit. I think it has been about twenty years since the pulsing chargers were found advantageous. New power-control electronics tend to be small/unassuming.

I assume you are aware of the downside of mains connections to boat electric as regards galvanic/electrolytic action {forgive me failing recollection of which mechanism is called what}.

Suggest you look over this site , and consider a phone call:
http://www.vdcelectronics.com/index.htm
http://www.vdcelectronics.com/about.htm

Unfortunately , they probably don't have a model fit for 250V....

[paladin]

If you use a.c. on the boat I strongly urge you to use an isolation transformer, and a benefit of that is that you can use any charging system that you want by tying to the appropriate transformer taps.
With the system that you propose you would either be forced to charge the batteries one at a time, or purchase two units to allow simultaneous charging, it won't work if you parallel the batteries. I believe there may be less expensive and better dual system units. I haven't looked as the systems that I have are for three independent batteries.

[carioca1232001]

........ I believe there may be less expensive and better dual system units. I haven't looked as the systems that I have are for three independent batteries.


Have a look at the battery-charger link below; Pro Mariner and Guest have quite a wide selection of isolated-output (1,2 or 3 outputs) at 12 V DC (nominal) on display:

http://www.defender.com/category.jsp?path=-1|328|51495&id=985

[Gary E]

You want FIRST CLASS ??

http://www.lamarchemfg.com/pdf/a40.pdf

Many models availabe

[carioca1232001]

The LaMarche chargers look like they employ traditional battery-charger technology and are consequently heavy and large in size.

In addition 'power dividers' need to be connected to the outputs of these chargers in order to provide multiple outputs.

Say, compare a traditional, heavyweight 12 V DC to 110 V AC / 60 Hz inverter to a modern one, that uses high-frequency switcher technology , followed by an electronically controlled bridge.

My preference is for the latter.

Infinitely smaller and lighter for the same power output.

[John Boone]

Hello Zane,

Take a look at the Xantrex products to see if they offer something to fit your needs. I have had a Xantrex xc5012 charger installed and operational for over two years now with out any issues and am well satisfied with the unit and it performance.

http://www.xantrex.com/web/id/180/p/1/pt/24/product.asp

If nothing else you may get some additional ideas.

What type of batteries do you have? Not manufacturer, but technology? Also, it might help folks if they knew the type , size and manf. of your inverter.

Good luck with your project.

John

[Zane Lewis]

Thanks for the responses.
To clarify. batterys are 2 deep cycle 125 amp hr, wet, maybe glass matt.
We have solar pannel. Previous one was 18 watt curent one is about 30 watt. They are dioded and into the battery. These have not proved satisfactory and the battery does not seem to hold a charge. Showing say 12.8 volts, run small fridge radio and light for 1/2 hour, volts rapidly droped to 11.5 and then when turned off recovered to 12.4 At times they have been run down to 11volts.

This makes me suspect sulpher plating.

Zane

[carioca1232001]

Thanks for the responses.
To clarify. batterys are 2 deep cycle 125 amp hr, wet, maybe glass matt.
We have solar pannel. Previous one was 18 watt curent one is about 30 watt. They are dioded and into the battery. These have not proved satisfactory and the battery does not seem to hold a charge. Showing say 12.8 volts, run small fridge radio and light for 1/2 hour, volts rapidly droped to 11.5 and then when turned off recovered to 12.4 At times they have been run down to 11volts.

This makes me suspect sulpher plating.

Zane

Now the 'dioded' part could be the culprit for the batteries not going over 12,8 V DC and rapidly depleting their charge.

'Diodes' are the electrical equivalent of one-way valves, excepting that they perform this function levying a fee, that is, they introduce a voltage drop of about 1,0 Volts.

Using a standard battery-charger or a solar panel designed for charging batteries with a floating voltge of 13,8 Volts, it should be clear that the batteries will not see more than 12,8 Volts. This in turn means that they will never get really charged as they should.

Install a multiple-output charger and shelve your problem.

[TMny]

>voltage drop of about 1,0 Volts
To corroborate Carioca , diode forward voltage drops are reported nominally .7V for silicon , but can range significantly upward of that (sometimes over 2 volts). Any solar PV above a couple watts needs a charge controller unless configured to chronically undercharge {presumably where Zane is}, whence sulfation results.

The solar PV installers DO use diodes (and circuit-breakers) to isolate faults in sizeable arrays . All this has to be integrated/engineered properly for good effects.
A combination solar/mains charger/controller may be required ??

[paladin]

The nominal output of a PV cell is normally over 16 volts and the batteries should never be overcharged with the setup that you have. I would suspect not enough light to the panels to allow a charge or defective batteries. The batteries should read 13.6-13.8 volts fully charged no load, and they have enough capacity to not require a pv charging system. I would suggest completely disconnecting the batteries at dockside, use an individual charger on each cell, either at the same time, or individually, and note the voltage prior to reconnecting them. Then place them under load one at a time and measure the voltage. You may be able to isolate one battery as being defective,

[Zane Lewis]

Thanks,
Paladlin I will be over with Dad on the boat next week so will have a look at checking them individually. And charging them separatly.
TMny I will thave my multi meter and check output from the panels. We have previously had crosion issues affecting the diode's and I will check either side of diode as well for V drop.
Thanks for the good responces, Zane

[dhic001]

I would suggest completely disconnecting the batteries at dockside, use an individual charger on each cell, either at the same time, or individually, and note the voltage prior to reconnecting them. Then place them under load one at a time and measure the voltage. You may be able to isolate one battery as being defective,

Zane,
See if you can borrow a battery load tester, auto sparkies have them. We had one at my last job, and it was a very simple way of checking whether the batteries were any good or not. A load tester will let you know whether the battery will carry its charge under load, something that a simple voltage test will not tell you. I've seen plenty of deep cycle batteries that were fully charged, but wouldn't hold up under a load test.
Daniel

[pila]

The automotive load tester will tell you right away if the battery(s) are OK. With diodes in the system, the charge voltage would necessarily have to be higher like Paladin mentioned.
I have my two "house" batteries in parallel, and they are 10 years old this summer, and likely are living on borrowed time, but that's good service I think. I paralleled them when they were new after reading Nigel Calder's book; the chapter on battery powered electrical systems. ( I'm not smart enough to figure this out myself):)
He claims they will last longer paralleled than singular wired. I can't argue with that considering the age of my old batteries.

[OldWolf]

I picked up Nigel Calder's book, and found myself in a new world of information and expertise! I have to completely gut my electrical system and rewire, so it's proving an invaluable resource. Been researching for over two weeks now...I'm new to boating, so it'll take awhile.

From what I understand, installing a charger isn't a bad idea at all, even if one (or both!) batteries are bad. Are there any real advantages or concerns about chargers that Zane (and I :-P) should heed? Reading the boxes and the sales literature makes each one seem like snake oil.

[Bob Cleek]

Tell your friend who sleeps with a CPAP machine to upgrade his unit. 120VAC/12VDC models are now commonplace. There is no need for a 120 inverter burning up your batteries. Just run the CPAP on 12VDC directly. They come with a standard 12VDC auto cigarette lighter plug. Your basic car battery will run one all night long with power to spare.

[Wayne Jeffers]

Yeah, almost all CPAP’s run internally on 12 VDC. They include circuitry to convert the 120 VAC to 12 VDC.

It is wasteful to convert your battery’s 12 VDC to 120 VAC so that the CPAP can then convert it back to the 12 VDC it runs on. Using the DC cord for the CPAP will use less electricity from the battery and the CPAP will run perfectly well on straight 12 VDC.

Expect a battery draw of only about 1 amp when running on straight 12 VDC. Figure 8 amp-hours for 8 hours use of the machine.

In my experience you will have to buy the DC power cord separately. But they’re cheap, unless the CPAP is a ResMed unit.

If you really want to stick with the high capacity battery set up, you should also consider getting two 6-volt golf cart batteries and wiring them in series to make one big 12-volt battery. It greatly simplifies the charging and you don’t have to worry about an older 12-volt battery dragging down its healthier 12-volt mate. You’ll also get more amp-hour capacity bang for the buck with golf cart batteries.

Wayne