Battery charger replacement

[Gordon GB]

Time to replace the original Sentry battery charger on Raven (GB Classic 42-1293). I've got 4 8D AGM batteries in my house bank, an 8D engine start battery (that I'm going to replace with an AGM battery) and a smaller generator start battery (that will also be upgraded to an AGM unit). I'm looking for recommendations for a new battery charger - what do people have and what do they like. I also have an Outback inverter/charger that keeps the house bank topped up.

 

[drb1025]

I recently installed a Blue Seas battery charger that is fully customizable, charges three banks, and has a four stage charging protocol. So far it is working great as expected. Also has a battery temp sensor that fine tunes the charging voltages.

 

[Comodave]

I have 2 Promariners on board. Have had them for a couple of years now, so far they have been great.

 

[Transaxial]

Time to replace the original Sentry battery charger on Raven (GB Classic 42-1293). I've got 4 8D AGM batteries in my house bank, an 8D engine start battery (that I'm going to replace with an AGM battery) and a smaller generator start battery (that will also be upgraded to an AGM unit). I'm looking for recommendations for a new battery charger - what do people have and what do they like. I also have an Outback inverter/charger that keeps the house bank topped up.

My 20 year old Freedom 2500 inverter/charger was boiling my 4 golf cart batteries that were 7 years old so replaced all of it. What to do??? There is a theory that the charger should be a per cent of battery bank amp hours. I think it is 25% of my 250 total amp hour battery capacity. So about 60 amps. A new Xantrex 2000 watt inverter charger was only $200ish more than just a high tech charger so I went that way. I added the remote which is really nice to be able to monitor voltage and manage a lot of things without having to go below. I am very happy with the consistent 13.6 v maintained by the Xantrex for $950.

I am not sure what to think about the charger having 25% output of total battery bank capacity. I have been managing batteries in trucks and heavy equipment for over 50 years and had never heard that before. At this moment I have at least a dozen 1 1/2 amp automatic chargers on equipment that is parked for the winter with 4 large lead acid 31 series batteries. They keep the batteries charged just fine without over charging. I have batteries last 10 years pretty often and without those little chargers they will be dead in a couple weeks from parasitic loads. Dead batteries will kill themselves very quick, specially here where they freeze and burst. What are the rest of you doing?

 

[FF]

"At this moment I have at least a dozen 1 1/2 amp automatic chargers on equipment that is parked for the winter with 4 large lead acid 31 series batteries. They keep the batteries charged just fine without over charging. I have batteries last 10 years pretty often and without those little chargers they will be dead in a couple weeks from parasitic loads. Dead batteries will kill themselves very quick, specially here where they freeze and burst."

YES , Yes , Yes a battery charger is to refill the battery.
Fine with a big hammer of a charger and a bunch of batts in a string.

Storing for months on end , with a big charger, always has the danger of if one batt craps out all are overcharged into trash.

A number of storage chargers is great insurance.

 

[O C Diver]

It sounds like you need a 2 bank maintenance charger as the house bank is charged by the charger / inverter. I've used these chargers on several boats without any failures. I prefer the 6 amp version, but don't see the dual bank one listed.

https://www.batterystuff.com/batter...s-12v-6-amp-waterproof-smart-charger-rs1.html

https://www.batterystuff.com/batter...bank-marine-waterproof-smart-charger-rs2.html

Ted

 

[ranger58sb]

Time to replace the original Sentry battery charger on Raven (GB Classic 42-1293). I've got 4 8D AGM batteries in my house bank, an 8D engine start battery (that I'm going to replace with an AGM battery) and a smaller generator start battery (that will also be upgraded to an AGM unit). I'm looking for recommendations for a new battery charger - what do people have and what do they like. I also have an Outback inverter/charger that keeps the house bank topped up.

Maybe just a good pair of jumper cables?

If the engine start battery has no other loads and is charged by the engine alternator... no other charger required?

If the genset start battery has no other loads and is charged by the genset alternator... no other charger required?

And you've already got an inverter/charger on the house bank? No other charger required?

FWIW, we have two dual-purpose start/house banks (300 Ah and 440 Ah), and a genset starter battery. An older ProMariner 40A charger currently services the 300 Ah dual-purpose bank, a ProMariner inverter/70A charger services the 440 Ah dual-purpose bank, and the genset alternator charges it's own start battery.

We are intending to add a new ProMariner 60A charger to the 300 Ah bank, and then be able to use the 40A charger to boost charges on both dual-purpose banks when that might be useful (as for example, at anchor, while we run the genset to charge, cook, heat water, etc.).

Some of that is driven by the charge acceptance rate of our AGMs, which is said to be higher than with FLAs. Odyssey (300 Ah bank) especially recommends higher charging capability (up to .4C), and even Lifeline (440 Ah bank) recommends a .2C minimum charging capability for longest life.

The big disparity in size from the two larger banks and the very small genset start battery is one reason why I removed that from the older original 40A 3-bank charger. Found it bubbling once, not great for an AGM.

-Chris

 

[caltexflanc]

I agree that given the description you just need a modest 2 bank charger for the start and gen. A NewMar or ProMariner are both good brands, I have had both and lean towards the NewMar for quality, good service and All-American-ness. \

Those old Sentrys are pretty good chargers actually, field serviceable by a lot of certified CruiseAir techs. I had one on my old Hatteras that did a great job feeding two big 32 volt banks once I got it serviced and dialed in.

Maybe I missed something, but is your GB 42 a single engine? That'd be rare. If a twin, is there a way to get separate batteries for each and the ability to parallel them? Or can you do that with your house and start today if need be?

 

[tiltrider1]

This is not a recommendation, it’s just some education. I recently needed to replace my backup battery charger. My Promariner from the early 90’s died. I determined that I needed a minimum 40 amp charger. Most the chargers were in the $800 range. Xantrex makes a 3 bank, 3 stage charger for $350. Now you have to wonder about quality when there is such a big price difference. Because I use a back up charger about once every 10 years I decided to take the chance with the Xantrex. It has worked flawlessly so far, but to be fair, so far has been one week of use and I haven’t turned it on since.

 

[Gordon GB]

Thanks everyone for your input - very helpful.

George, in answer to your questions, I do have twins and I have a switch that allows me to parallel the house and engine start batteries and I recently had to go that way as my engine start battery has gotten pretty weak.