charger choice - Prosport 12a or Guest 10a

[Northeaster]

Hi folks - looking for a bit of advice!!

- 30ft sailboat
- dock power (although may unplug when away form boat for days on end - plug in while we are on boat) Currently have cheap 100 ft (read approx 16 or 14 guage) ext cord to reach receptacle from end of heavy-duty shore power cord.
- Bank 1 - 1 group 24 flooded start (1 year old)
- Bank 2 (house)- new 2 group 27 flooded

- Yanmar 2gm - stock alt (guess is 35a)
- no fridge, no radar

- use raymarine C80, depth, VHF when sailing
- some 12v light use at night.


I wanted to buy from my local marine store, as it's fast / good service.

Having read about their 2 choices, in my price range:

1 prosport comes prewired with an AC male plug - I would likely cut that off, and hardwire it to my panel - as boat has breaker for charger (old, small charger died)
pros - it puts out up to 12 amps to one battery if needed, whereas the Guest 10a charger will only do 5/5

- The Prosport has a charge, conditioning, and maintenance stage - Is taht better / worse than the 3 stages of the Guest charger?

Both chargers are on the page linked below!!
Chargers / Inverters - The Binnacle: Your Complete Online Marine Store

Besides looking for recommendations of one over the other, I have a couple of questions:

Both chargers say they charge 2 banks - but also say they charge 2 12v batteries!!
Can I hook it up to bank 1 - my start battery, and bank 2 (which has 2 12V batteries)?

Would I be better to hook the bank 1 charge wires to the 1st house battery, and the bank 2 charge wires to the 2nd house battery? As they batteries are already wired in parallel, would that they put 24 volts in them, or create other problems?

I would appreciate any feedback!!
PS I did read numerous articles on the subject in the archives, but still needed clarification!

[sailingdog]

A 10 or 12 amp charger is going to be a bit underpowered for the battery banks you have IMHO, especially if you're only going to be charging the batteries when you are at the boat, and not leave it plugged in. Of the two, the Prosport would make far more sense, since it has the higher charging capacity.

Wet lead-acid batteries self-discharge about 1% per day or so. They also start to sulphate if left discharged for any extended period of time. Your house bank is two Group 27 batteries or about 220 amp-hours in capacity. That means, over the course of a week, it will lose about 10-12 amp hours or so, not counting whatever loads you subjected the battery to when you used it last. If you're not at the boat every weekend, I can see your batteries dying rather prematurely.

BTW, when a charger manufacturer says batteries, for all intents and purposes, a battery bank of multiple batteries connected in parallel is effectively treated and electrically equivalent to a single battery of the same size. Hook up one charging set of leads to the house bank and one to the starting bank.

[Northeaster]

SD - thanks for the advice, and the clarification on the fact that 2 batteries in a bank can be treated as "1 battery".

I would like to get the larger Prosport 20, but it's over ywice the price. I wasn't going to leave the shore power on all the time, as there is no fride, etc, running all of the time. If the risk of fire, etc is not great in leaving it pugged in all the time, I may do that!

Would you think it best to cut off the prewired plug, and wire it to teh existing panel breaker?

PS I don't know how to post pics here yet, but have some at:

Yacht Maintainance & Boat Building - Cruisers & Sailing Photo Gallery

You can click on one of my pics, and view all of them, to see some of the before and after pics of this winter's projects!

[camaraderie]

In my opinion, neither of these chargers is suitable for your situation. The Guest is simply 2x5amp which is WAY low for your house bank and unnecessary for your starter battery. The Prosport is a wierd charging system and has the ability to charge 2 batteries in any configuration but not 3 batteries even if wired into 2x12V banks. They are also very unclear on their conditioning stage which is NOT an EQ stage but takes place during absorbtion somehow. It also has NUMEROUS customer dissatisfaction complaints.
If I were you I would be looking at something in the 15-20 amp range. The Guest 20amp intellichargr goes for about $200 and gives 10/10 output. With this charger, I'd hook one output to the house bank nd the other to the starter. Diagram are included in the manual. Obviously there are many choices but I was trying to stay with a commonly found product close to your original price range.

[sailingdog]

Leaving any electrical equipment plugged in and turned on all the time does have some risk associated with it. The big problem IIRC, was the people using automotive, non-marinized chargers on a boat, since corrosion rapidly becomes an issue. IMHO, a properly installed, intelligent three-stage marine battery charger isn't much of a danger. The only reason I hesitate to recommend this to you is:

Currently have cheap 100 ft (read approx 16 or 14 guage) ext cord to reach receptacle from end of heavy-duty shore power cord.

Cheap extension cords are not the way to go in a marine or outdoor situation, especially given the distances you're running it.

Cam's recommendation of a Guest 20 amp charger is a good idea... they make a 20 amp, two-bank, waterproof charger that sells for about $190.





I'd also recommend getting a decent double or triple insulated heavy duty 12 AWG extension cord at a minimum.

[camaraderie]

I was actually referring to their 16202 model intellicharger which is more intuitive and gives bettr user info for 10 bucks more. Can be had here on sailnet for 199.

[Northeaster]

Thanks Cam. I was unaware of the customer complaints with the Prosport. I am a bit leary of their 3 "stages" as well, as it is charge, conditioning and maintenence. In their brochure, they give the voltages that each stage delivery, but not the amps. It seems much different than the normal 3 stage charges, which do bulk stage, reduced stage (forget the actual name of stage), and maintenance stage.

Can you explain why I can't hook the bank 1 leads to the start and the bank 2 leads to the house bank (instead of just one house battery)?


SD - yes, I know the long cheap cord is bad. Haven't really used it to draw much power yet. Sad thing is, almost all boats at the marina have long cheap cords, as the AC receptacles are all far away!! If I were going to draw alot of current, I would (and may still) invest in a good 100' heavy gauge ext cord. Right now, the only good one I have is only 50'.

[Northeaster]

Cam - just found this link that says it will charge / monitor start battery, while diverting all other avail power to house (they say trolling) battery(s)!!

Customer complaints notwithstanding.

http://www.mermaidmarine.com/documen...ryChargers.pdf

Going to search for complaints now - any quick idea what they were about?

[camaraderie]

Northeaster...yes it DOES divert all power into one "channel" and that is attractive BUT it ALSO does NOT handle 4D or 8D batteries which is essentially what you have created with a dual group 27 house bank. The multiple complaints were for failures of the product...found them on a google search. I strongly suggest that this product is inappropriate for your configuration.
Reviews: Bass Pro Shops ProMariner® ProSport Onboard Chargers Customer Ratings & Reviews - Top & Best Rated Products

As to the hookup of output 1 and 2 to your individual house batteries, this is entirely possible but then what will you do for your start battery? With a 10 amp output replacing the maximum 100 amphours of house battery use you might have before reaching 50%...you have no problem in recharging the bank while the other lead can keep the start battery topped off.

Alternatively... You can always start with the house bank and then use the alternator to charge the start battery. I would suggest an echo charger but that costs as much as the chargers you are looking at.

[btrayfors]

Suggest you look at the Iota brand chargers. They're smart and very cost effective. Also, well suited to keep flooded batteries (as well as other types) in tip-top condition. You can leave them on all the time.

A 45A or 55A model would be appropriate for your situation. These can be had for about $155 or so, with the IQ-4 smart-charge option. Be sure to get this, either built-in or as a separate plug-in.

I have had two of these for years, and have seen lots of customers and friends be very happy with them. Truly excellent chargers, and a steal for the $$$ these days.

Bill