Do you really need a $400 charger?

[US1Fountain]

Check closer on the charger specs. Some of the cheaper 20A 2 bank chargers are really just 2 10A chargers in a single housing. Neither bank will recieve more than 10A.

Your better 20A 2 bank chargers can throw all 20A to either bank, depending on state of charge. My Promariner 40A 3 bank is such a charger. It'll send those 40A to where its needed, or split between the 3 banks as needed.

[jamhass]

IMHO:

It is indeed more important to get a good, 3-stage programmable shore power controller than a high amperage one. Assuming you stay at marinas for more than a day at a time, even a relatively smaller charger will get the batteries up to full charge nicely. Sufficient programability will allow you to optimize the profile to your batteries.

We have a 500 AH bank, and our shore power charger is only 40 A. We see 40 A only occasionally as the charger fairly quickly goes to float, so a higher capacity charger would do little. In our case, we have a relatively low-current boat, so a 40-A charger does a fine job of maintaining our 12v house loads when at the dock. If your housekeeping 12v loads are higher, a higher-amperage charger might be in order.

[john61ct]

Quality AGM needs .2 - .4C as a minimum for longevity.

For FLA not much point going past .2C, unless you may expand later.

And of course the **charging** rate only starts after concurrent **loads** are being taken into account.

[a64pilot]

Just for whatever it’s worth, three stage chargers are really only two stage.
Balmar 614 alternator controller being an odd ball.
But what happens is that you have two voltage set points. Absorption and float.
Bulk is the charger trying to achieve absorption voltage, but can’t cause its current limited, it is not a separate “stage”.
Once absorption voltage is reached, usually a timer is started and that voltage held until the timer end, where the voltage is set to float.

Single stage chargers are almost universally non adjustable, so they are never the right voltage, for anything. If the voltage is high enough to charge, then it’s too high to float. It’s actually surprising that batteries lasted as long as they did with those things, but I bet there is still a bazillion of them still out there.

[rgleason]

Hi John, what does this mean please? "unless you may expand later"

For FLA not much point going past .2C, unless you may expand later.

[beachbumlou]

Greetings Thom225:


I am interested in your Renology solar setup – you have two batteries connected to this Renology kit, correct?


I have four 108ah AGM’s connected as a 48v battery bank for my Electric Yacht inboard motor. The batteries are charged with a DualPro Quad charger that has worked fine for 8 years.


The problem I have faced is inconsistent shore power at a couple of marinas in Hampton Roads. This past February, the marina had a short in my pedestal which blew my circuit breaker. I did not visit the marina until the end of April and they neglected to mention this power incident. All my batteries sat with no shore power to the charger for 3 months. Completely dead – granted they are 8 years old now. Since my AGMs are my propulsion system, I want to keep them optimally charged.



My question, if I am looking to augment shore power with solar (to avoid gaps in electricity) would I need one or two of these kits?
Any info/suggestions would be appreciated.


Thanks,


LOU

Originally Posted by thomm225

You could charge your battery bank with solar and never have to hook up to shore power ever again.

That's what I do with my two 12 volt batteries that I have in parallel. The solar and the batteries also provides all my power when I go out on my short 3-8 day cruises and that is with running an AC fan all night which take quite a bit of power from the inverter

My outboard doesn't have an alternator.

Here's a kit from Renogy with everything you need for just a bit over $160.00. You can find a cheaper kit also if you want with a PWM Controller.

https://www.amazon.com/Renogy-Monocr...05311526&psc=1

[motion30]

Originally Posted by travellerw

I know a few people who are using Iota chargers (with the IQ4 option). $160USD will get you a 55A multistage charger.

Of course its not "marine grade". However they seem to be pretty reliable if properly installed in a dry location. Might be an option if you are on a budget.

I had installed the Iota Chargers on my other boat and I recommend them. They also can be linked together

[mvmorningstar]

That is a 10a charger with separate banks. Ok for maintenance charging. Probably take a day to recharge from 50%. Low power chargers may not bring battery bank to 100%. Shorter life. I just replaced a 10yo agm bank of 4 L16. $2k. I want an excellent charger to bring them up to 100% quickly with temp monitoring and adjustable charge routines. For my money- inverter chargers are the best bang for my long term buck

[mitiempo]

Originally Posted by beachbumlou

Greetings Thom225:


I am interested in your Renology solar setup – you have two batteries connected to this Renology kit, correct?


I have four 108ah AGM’s connected as a 48v battery bank for my Electric Yacht inboard motor. The batteries are charged with a DualPro Quad charger that has worked fine for 8 years.


The problem I have faced is inconsistent shore power at a couple of marinas in Hampton Roads. This past February, the marina had a short in my pedestal which blew my circuit breaker. I did not visit the marina until the end of April and they neglected to mention this power incident. All my batteries sat with no shore power to the charger for 3 months. Completely dead – granted they are 8 years old now. Since my AGMs are my propulsion system, I want to keep them optimally charged.



My question, if I am looking to augment shore power with solar (to avoid gaps in electricity) would I need one or two of these kits?
Any info/suggestions would be appreciated.


Thanks,


LOU

Best to forget the Renogy kits. With a 48 volt battery bank you need is=deally a controller designed for this voltage. Victron has a few.

[ontherocks83]

Originally Posted by rgleason

Hi John, what does this mean please? "unless you may expand later"

I believe they mean that getting a charger over 20% capacity of the battery bank ah capacity is a waste. i.e. if you have a 200 ah battery bank anything over a 40amp battery charger is a waste due to acceptance rates of a FLA.

[mitiempo]

Originally Posted by rgleason

Hi John, what does this mean please? "unless you may expand later"

What John means is that you might enlarge the battery bank at a later date. If you do a larger charger can make sense.

[john61ct]

Originally Posted by a64pilot

Bulk is the charger trying to achieve absorption voltage, but can’t cause its current limited, it is not a separate “stage”.

Sure it is, just that the timing of that transition is not regulated by the charge source,

more by the battery type, SoC and current level.

If you want to be nitpicky, there are indeed only those two **charging** stages: when the profile is optimized for a given installation's usage patterns,

dropping to Float only happens after charging is complete.

And some chemistries prefer zero Float, just Stopping when endAmps is reached is better for longevity.

Firefly for a lead example.

[john61ct]

Originally Posted by beachbumlou

Greetings Thom225:


I am interested in your Renology solar setup – you have two batteries connected to this Renology kit, correct?


I have four 108ah AGM’s connected as a 48v battery bank for my Electric Yacht inboard motor. The batteries are charged with a DualPro Quad charger that has worked fine for 8 years.


The problem I have faced is inconsistent shore power at a couple of marinas in Hampton Roads. This past February, the marina had a short in my pedestal which blew my circuit breaker. I did not visit the marina until the end of April and they neglected to mention this power incident. All my batteries sat with no shore power to the charger for 3 months. Completely dead – granted they are 8 years old now. Since my AGMs are my propulsion system, I want to keep them optimally charged.



My question, if I am looking to augment shore power with solar (to avoid gaps in electricity) would I need one or two of these kits?
Any info/suggestions would be appreciated.


Thanks,


LOU

Start a new thread, will attract more qualified advice for your unusual needs.

[john61ct]

Originally Posted by mitiempo

What John means is that you might enlarge the battery bank at a later date. If you do a larger charger can make sense.

Originally Posted by ontherocks83

I believe they mean that getting a charger over 20% capacity of the battery bank ah capacity is a waste. i.e. if you have a 200 ah battery bank anything over a 40amp battery charger is a waste due to acceptance rates of a FLA.

Yes put both together exactly what I meant.

[Diesel Bill]

Originally Posted by travellerw

I know a few people who are using Iota chargers (with the IQ4 option). $160USD will get you a 55A multistage charger.

Of course its not "marine grade". However they seem to be pretty reliable if properly installed in a dry location. Might be an option if you are on a budget.

I put an Iota in 6 months ago. Very pleased with it. Keeps my 4 golf cart 6 volt and 3- 12 volt start batteries topped up very well. Ordered with IQ4 option.
Seems like a good product. No fancy gauges. Just a flashing green LED tells what mode it's in.