Battery charger for my center console?

[Frank O]

I've read through a number of threads on battery chargers here and understand some of the basic issues involved. But I'd like to quickly describe my situation to see if it results in any specific thoughts.

I just repowered my 21' center console with a 2011 Mercury OptiMax 250 outboard. On the advice of the manual and the installer, I replaced my old deep-cycle batteries with a pair of cranking batteries (Interstate 24M-XHD, delivering 800 CCA, 1000 MCA).

I keep the boat in a slip, and bringing the batteries home to charge isn't an attractive option.

The marina tells me I'll need a true shore-power cable if I want to run a charger on the boat from dock power. The boat doesn't have a receptacle or any 110v wiring on it. This approach in theory would be feasible, but I gather I'd have to cut into the boat's console to install a receptacle, which I'm not keen to do. I'd like to put a new fitting on the end of a shore-power cable so I could squeeze it through one of the ventilation holes of my boat's console, but I gather that would make it non-code.

Solar seems like an interesting option. I've read posts here that indicate that boat batteries are hard to charge off reasonable-sized solar panels. (I'd want something small enough to stow in a dock box.) But when I've had the batteries at home, I've gotten decent charges from a plug-in system that puts out 1.25 amps per battery at 12 volts.

For this situation, does solar sound feasible?

 

[M9.9]

Re: Battery charger for my center console?

Hi, my opinion on solar panels is, they will become the charging method of the future once the pricing drops and output increases v. cell size.
In particular, for those using onboard 12 volt power for lighting, trolling motors and such.. but do not have a source for recharge of the battery while out. Problem is, time/current usage v. solar power output current and time needed to recharge which may, in most cases, Not fully charge a battery in a day or so.
But I use a smaller (tiny) solar panel in the car in winter which continously supplies an amp/hr to the battery and the battery has not gone dead yet. Since the cold can rob the battery of as much as 40% of its rated cold cranking amps depending on temperature.

What I would like to see and may design is a bimini top using flexible low-weight solar panels that in an area of appx 4' x 6' can produce current equal to or exceeding 6/amp/hr which at least in the case of smaller boats without a while-you-go charging source (Engine w/a Charging Circuit), will charge the battery in hours (daylight needed of course) instead of days. In your case I'm sure there are others here who may be able to better advise on US laws regarding requirements for boat ac recepticles.

 

[Silvertip]

Re: Battery charger for my center console?

1) 1.5 amp chargers are not "chargers" -- they are "maintainers" whose job is to maintain a battery at its fully charged level.
2) Is it marina policy that states you need to use a true shore power cord? If so, there should be no issue with removing the existing cord end and replacing it with a standard receptacle. However, rain will follow that cord downhill into the boat so it would be wise to add the shore power connector.
3) There are recessed 120 volt power entrance plugs like those used on motor homes and travel trailers. These would require a much smaller hole and have a waterproof rubber cover.
4) You said you had two starting batteries. How are they connected in the boat? Or is just one connected and the other going along for the ride?
5) Solar is out of the question unless you have enough roof area to mount a substantial solar panel. These panels are also targets for thieves so consider that option carefully.

 

[M9.9]

Re: Battery charger for my center console?

Hi Frank O,
After doing a quick search, I see there are solar panels available that can produce almost 6amp at 12 volts. The panel size is 47.25" x 27.25", weighing about 16 lb. Wondering what the pricing is?, will check.
http://www.wsetech.com/solarpanels.php

 

[Silvertip]

Re: Battery charger for my center console?

Does this look like a reasonable solution????????? For $455 plus the cost of the charge controller there would have to be no other alternative to justify this. And very likely the panel would end up in someone elses hands in short order.

http://www.amazon.com/dp/B004DR6Y6U...e=asn&creative=395109&creativeASIN=B004DR6Y6U

 

[Frank O]

Re: Battery charger for my center console?

Thanks for the comments.

1) 1.5 amp chargers are not "chargers" -- they are "maintainers" whose job is to maintain a battery at its fully charged level.
5) Solar is out of the question unless you have enough roof area to mount a substantial solar panel. These panels are also targets for thieves so consider that option carefully.

We spend a lot of time in my household charging car-sized batteries with tenders and chargers of various amperage ratings. I find that a 1.25-amp tender works well enough for me; ours will bring a battery back up after a fair amount of usage, but it may take a couple of days. Not really a problem, since I use the boat once every other week on average. On the other hand, I find that our 0.75-amp tender seems underpowered for my typical usage.

I see that Sunforce makes several solar panels sold by marine dealers. They have a "15-watt" panel that's said to put out "up to" 1 amp. I imagine that's with full sun on a cloudless day; might be on the slim side for my needs. And that panel is 15.5" x 41.5". I don't have my dock box's dimensions handy, but I have a feeling that's not going to fit.

2) Is it marina policy that states you need to use a true shore power cord? If so, there should be no issue with removing the existing cord end and replacing it with a standard receptacle. However, rain will follow that cord downhill into the boat so it would be wise to add the shore power connector.
3) There are recessed 120 volt power entrance plugs like those used on motor homes and travel trailers. These would require a much smaller hole and have a waterproof rubber cover.

Yes, the marina says it needs to be a true shore power cord. The ventilation holes in my console aren't all that big; a standard receptacle may not fit. I'd be interested to know more about what kinds of modifications to the cable are considered as taking it out of code. Your point about the rain also occurred to me; if I did have a cord entering the console, I'd want to have it run up to the ceiling so that there isn't a gravity path that will put water anywhere it can cause trouble.

4) You said you had two starting batteries. How are they connected in the boat? Or is just one connected and the other going along for the ride?

It's a pretty standard two-battery setup with a Perko switch that lets you connect either or both to the outboard system.

 

[Frank O]

Re: Battery charger for my center console?

Does this look like a reasonable solution????????? For $455 plus the cost of the charge controller there would have to be no other alternative to justify this. And very likely the panel would end up in someone elses hands in short order.

http://www.amazon.com/dp/B004DR6Y6U...e=asn&creative=395109&creativeASIN=B004DR6Y6U

Hmm -- they don't give dimensions of the panel, and the price is on the rich side for my budget. I hear you on the risk of having one stolen, though our marina seems to be pretty safe with a lot of liveaboards keeping an eye out.

 

[M9.9]

Re: Battery charger for my center console?

The panel mentioned in my last post is presently on sale at 275. Now waiting for a spec-reply on the regulator for a max charging output of 6amp at between 12.6 and 13.6 volts DC, with the latter being the cut-off point and probably 12.3 volt battery level as being the auto-on point, using the KISS principle. Should know more hopefully tomorrow.