battery charger size

[hcalmar]

I have been reviewing the threads on battery charger reccomendation.What size is appropriate for a 37C in terms of amps? Has anyone heard of the IOTA charger mentioned on Ebay here?

eBay Motors: 45 AMP BATTERY CHARGER RV MARINE REMOTE CONTROL NEW (item 4603921962 end time Jan-20-06 17:12:31 PST)

Hal

 

[Nick]

Hal,

Not familiar with the unit on Ebay; we have a Sentry 40 AMP battery charger in our 37. I believe it is the Model FR 12 40A/3XJ. suitable to charge three banks. I have 2 8D batteries connected to the charger. The unit is about 5 years old and is trouble free. I also have a Xantrex charger/inverter but do not use the charger mode because I have cooked the batteries by having the inverter/charger in charger mode and battery charger on simultaneously. Seemed to mess up the sensor for the charging circuits.

Sentry is owned by TaylorMade as far as I know.

http://www.cruisair.com/sentry.html

Nick

 

[Jaxfishgyd]

I bought a Truecharge +40 by Xantrex 2 years ago and boy was that a mistake. It can charge up to 3 banks (so it claims) but it will cook the batteries in the 2 banks I had it hooked up to if I leave it on. I had to add water after just 7 days when I left it on the first time.
So now I just have it hooked up to my deep cycle bank and only turn it on for a short time when needed. (We are full time liveaboards so do use 12v systems daily)
My starting battery bank is no longer on it as we use the boat just about weekly and I no longer have to worry about cooking them with the charger

 

[REBrueckner]

I removed the old 60 amp ferroresonant charger aboard and added three Statpower smart chargers and love them. I later added a Xantrex Freedom 2500/130 inverter/charger and it also performs flawlessly. The Statpowers regulate based on the first output, I believe the left most of the three outputs. I add clost to a gallon of water for 7 8D's during heavy summer use over six months, hardly any during six months of dockiside winter idle.

You can charge wet cell lead acid up to 25% of their amp hour capacity, 40% for gel, and 100% for AGM. Say you have 4 wet cell 8D battsof 220 amp hour each. Thats 4 x 220 or 880 amp hours. 25% of that is about 220 amps and that's the maximum charge the batteries will take on bulk charge (the highest charge rate) so a larger charging capacity doesn't help. If the batts were AGM, you could charge at 880amps!!! almost four times faster. But AGMS cost more.
Also note that if two of these batts are for start and not for accessory use, then its unlikely you need to plan to charge them at the top rate. But you'll have to charge the other two (accessory) batteries more often.
In general, a lower charge rate doesn't hurt and if you are on shore power makes little difference; if trying to limit genny run time, it's critical!!

 

[jim rosenthal]

I had a similar problem with a Statpower Truecharge 40, which I solved by leaving it on the "hot" setting for temperature control. Since then I have not had problems. I does make me wonder how it would behave if the temp sensor was hooked up, which is an item I don't have. I think when you set it for "cold" it charges too aggressively. The batteries keep their water (at least I think so, I am checking on them today) and they don't have any trouble turning the engines over.

 

[Genesis]

I have a Charles 5000 series charger which replaced the old ferroresonant one that came on the boat (it died)

I like it. It doesn't boil the batteries but DOES keep them topped off. I bought the 40 amp model and use a combiner to equalize and charge the second bank - I only hooked it up to the house bank.

 

[REBrueckner]

Statpower Chargers: Users should be aware that there are two critical settings which must be selected via switches at the charger. As noted, one is the temperature setting. After a few years of satisfactory use I decided to add temperature sensors, but this was to assure proper levels of charging over wide temperature ranges without having to make manual adjustments. Prior to that, I used the HOT setting in summer, the middle setting in winter while I have heat on.
Also, Statpower chargers require you to selected the battery TYPE: wet cell, AGM or GEL. Again its a selector switch.
If your batteries are being boiled off, something is WRONG. Smart chargers do NOT do that! Either the batteries or a cell in one are in poor shape, one of the above settings is incorrect, or the charger is defective. And of course you should NOT EQUALIZE very often as that intentional overcharging will boil off electrolyte.

 

[Beckytek]

I have the trucharge 20 by Xantrex and it works perfectly. Last winter I left the charger on all the time (5 months) and did not have to add water once. The charger turns itself off after the float stage and stays off for 21 days if there is no activety. Then it checks the battery voltage to see if chargeing is required, if not, off again for 21 days etc. On the boat this past summer I only turn the charger on when I leave the boat after the weekend. While I'm using it, the motor keeps them charged. I only use the charger for the house batteries as the starting battery is only used to start the engines. I have the temperature sensor on the battery so my temp switches are ignored. I didn't have to add any water to the batteries this whole summer, -golf carts. Ron