Charger/Inverter and AGM batteries

[(Nobody You Know)]

Here's the plan:

Replace Gp 8 lead acid (floaded cell) batteries with (4) Gp 31 AGMs.

Replace older charger with charger/inverter with 3-setting (led acid, gel, AGM) chargeing capability and 2500 watt output. Or, replace older charger with (separate new) charger and inverter.

The needs:

Sustain ice maker, and occasionally microwave or coffee maker when cruising and at anchor ("managed" power, ok?). And provide proper charging for AGMs.

Would like to install either Charger/Inverter or Inverter only in v-birth under bunk to keep away from engine room heat.

(Would like to avoid "Broke Back Battery" syndrom too ).

Questions:

Would an inverter emit annoying buzzing noise so as to disturb sleeping passangers in the v-birth? **

Will a "modified" sine wave be ok to run ice maker 120v compressor or must I invest in a "true" sine wave (much more $$$)?

Is it a big complicated deal to connect 120V to one side of control breakers (30 AMP splits)?

** When underway there's a lot of air moving around in the engine room and is not near as hot as when I shut 'em down at the dock - where I plug into shore power anyway. Will be running the inverter at anchor where the warm bilge may affect the inverter performance. I don't know how big an issue this will be (also, frig. and many lamps are DC).


Responses are appreciated!

 

[thoward]

You need your inverter/charger close to your batteries. What do your lights, fridge, tv, water pump, hot water heater and sound system run off? Combo units are nice if it covers the capacity you need. If you need higher capacity than about 2500w then you will end up with individual units.

 

[dastahl]

Invertes hum to loudly to put under a bunk. I personally would not like to sleep over batteries, even AGMs which are the safer of the bunch.
I put the inverter\charger close to the batteries with 4/0 cable in the ER with heat sensors so the thing can try to compensate. For 4 years its worked great.

2500 watts sine wave inverter/150 amp charger/880 AGM amp hour battery bank. It runs the fridge, ice maker, lights, all plugs (thus the Microwave/cofee), TV, for 24 hours.

Skooch 42 LRC 401

 

[REBrueckner]

I don't know of an easy way to determine if a particular inductive/capacitive load (motor) will run ok or not on modififed sine wave. A (one amp) fan in your engine room, run for a few hours after shut down, or just venting the engine room via open doors, should avoid any potential inverter overheating. It sounds like most of your inverter load will be the ice maker...see what the wattage is...maybe 200 watts or so(?)...anyway, likely no where close to 2500 watts, so overheating should not be a problem. Location in a closed area under a bunk could get just a hot as an engine room..ventiliation is needed.

How do you run the ice maker currently: genny?

In general you will find a combined inverter/charger more economical than separate units; e-bay offers reconditioned units,some with 90 day warranties at less than half price.

"Is it a big complicated deal to connect 120V to one side of control breakers (30 AMP splits)?" I do not understand this question. My Xantrex manual had a multitude of wiring options;likely you can see them online...all brands would be similar. The biggest issue is deciding which option to use followed by having to run required wires in cramped spaces.

To see if you 4 AGM's are big enough(adequate amp hours) see my 12-03-05 post "DC System Design". Battery bank size will depend on how often you are willing to run your genny for charging. Note that AGM's can take a big bulk current for rapid charging..size your charger accordingly to minimize genny run time.

If all this is for ice cubes, you can consider utilizing your frig ice tray unless usage is too great or filled with other items.

 

[garyd]

Timely thread!

I'm just about to go through this myself. I have some of the same questions. My current charles battery charger is original and is loud even though it is in the engine room. The inverter I bought says not to mount it in the engine room because heat and I suppose fire if fuel was to get on it somehow.

My battery of choice is the rolls. It comes with either a 7 or 10 year warranty and can be deep cycled 2000 times. I'm going to bite the bullet and buy one for the house battery/inverter

garyd

 

[SKYCHENEY]

Why AGM's? You should read what Calder says about batteries first. I'm not sure that you will ever really recoup the cost of AGM's over lead acid deep cycle batts. If, you don't have a good place to vent L-A batts, then maybe AGM's would be best, but otherwise I'm not sure it's worth the cost. Sometimes the simple old ways of doing things are hard to beat.

 

[Pascal]

Nyk,

first, keep in mind that your inverter needs to be as close as possible to the batteries... 6' is usually as far as you want to be and will require 4/0 cables on a 2kw+ inverter.

i would prefer not to have inverter or batteries in sleeping quarters. maybe i'm a little paranoid but i dont' like it. my freedom 30 buzzes, not too loud but certainaly loud enough to be heard in a vee berth.

i installed it in the genny room which doesn't get as hot as an engine room but while charging on genny, it does get hot in there. not a problem even in summer. i think that between sleeping quarters and engine room, i'd stick the the ER. reason for warning against ER installation is that no inverter is spark protected... not an issue with diesel boats.

True sine is usually needed for some high end electronics, not for a fridge or ice maker.

Group 31 are only about 100a/h arent' they ? 4 of them will only yield 200 usable a/h how much are they ? WM catalogue has some G31 AGM for about $220... a pair of golf cart batteries only cost $130 and gives you 220AH. while that's a WM price... that's still $2.20 per AH vs $0.59... yikes.

a large inverter charger is better in my opinion than two separate units since the charger is much larger than most standalone unit. my freedom 30 charges at up to 130amps...

instalation of the F30 was pretty easy. the 53 has two legs on the panel, one for AC one for everything else. I split the "everything else" side into two subpanels... one for what was to be inverter powered, the other one for things like charger, water heater, etc... which i didn't want on the inverter. it only took minor rearanging of the breaker. I added a 30amp breaker to the non inverter power section which feeds the inverter with regular duplex wire. The inverter output is then connected to the other sub panel feeding the items that can be inverter powered. simple. when shore or genset is disconected, the inverter automatically kicks in. when AC comes back in, it goes back to pass thru mode.

to insure that you get maximum charging capacity and full 30amp pass thru, the freedoms have a second input which is conencted from the Air con leg.

works as advertised, no need to replace the expensive rotary switches...

 

[Brian Degulis]

Most inverters have fans so it's not only the hum but fan noise as well. The only thing I've seen that modified sine wave has trouble with is charging units. Computer battery back ups, tool chargers etc. In all my past boats (all had inverters) that's the only thing that was a problem with the modified sine wave.

I just put an Outback 32V unit in my 61MY nice unit. You might take a look at them they are all pure sine wave and don't apear to be much more costly than other units that are modified sine wave.

Brian

 

[(Nobody You Know)]

Many thanks for the great feed back. Please let me respond to the many issues raised in this manner:

“What do your lights, fridge, tv, water pump, hot water heater and sound system run off”. thoward.

Most lights, water pump, sound system is 12Volt (40’ DCMY). Fridge is AC/DC. Will crank ginny if need hot water. Hardly use TV, try to read instead.

“I personally would not like to sleep over batteries, even AGMs which are the safer of the bunch”. dastahl.

Batteries would stay in bilge. The idea of I/C in v-birth is nixed. 6’ from batteries makes since (and easier).

“How do you run the ice maker currently: genny?” REBrueckner.

Yes periodicaly, or not at all on short runs.

"Is it a big complicated deal to connect 120V to one side of control breakers (30 AMP splits)?" I do not understand this question.” REBrueckner.

“instalation of the F30 was pretty easy. the 53 has two legs on the panel, one for AC one for everything else. I split the "everything else" side into two subpanels...” SKYCHENEY.

I have a 50AMP-240V shore system with 2 optional 30AMP-120V connections. 50AMP runs everything. One 30AMP will power up on side of my AC breaker panel. A second 30AMP will power up the other side. It’s my guess (without having thoroughly studied it yet) that I will be able to run one side or the other with the inverter and “manage” by switching off breakers that would overload it (stove, water heater, HVAC). My gut feeling is this connection will not be as hard as I fear.

“to insure that you get maximum charging capacity and full 30amp pass thru, the freedoms have a second input which is conencted from the Air con leg.” SKYCHENEY.

You lost me on this one SKY. I will go online and try and read up on this.

“My Xantrex manual had a multitude of wiring options; likely you can see them online.” REBrueckner.

Excellent idea. I need to do this.

“The only thing I've seen that modified sine wave has trouble with is charging units.” Brian Degulis.

A true sine wave inerter mfg. (forget which one) boast that anything less can damage AC motors. I was also concerned about pluging in the notebook pc. But then this is virtually always done while at dock and on shore power (and wifi).

You all have been very helpful. Further advice and comments are appreciated.

 

[Pascal]

"“to insure that you get maximum charging capacity and full 30amp pass thru, the freedoms have a second input which is conencted from the Air con leg.” You lost me on this one SKY. I will go online and try and read up on this.


actually, that was me... the freedom series has TWO inputs and TWO outputs.

since each input is rated at 30amps, as well as the transfer switch and the output, if you only use one input, you can only use 30amps pass thru and charge. pass thru means that when you are connected to shore/genny power to the circuits connected to inverter goes thry the inverter built in transfer switch.

if you connect the second input, you get a full 30 amps for your loads AND another full 30 amps for charging. both fed from breakers on different legs of your panel.

it sounds a little complicated but it's actually easier than using an external transfer switch... replacing your rotary with a 3 position isn't cheap...


it sounds like you panel is like mine... when connected to a 125/250-50 shorepower you get 50amps to both legs of your panels... or you can connect with dual 30amps and get 30amps to get by.

with a inverter similar to the Freedom series, you'd want to make sure that your Air cons are on one leg, and your Ship services on the other, if not already setup like that. that's how Hatt setup the 53s...

in that case, the inverter only feeds loads on the Ship service side. splitting that side ensures that you dont' attempt to power things you woudln' want to power by inverter like your WH or charger. it's physically easy... you just move the non inverter powered items at the top of the line of breaker, cut the bus between the last one and the first of the inverter powered circuits. add a breaker to the to to feed the inverter... and then feed the bottom part by the inverter output.

not easy to describe, but if you go to the xantrex site and download the manual for the freedom series, you'll see the diagram (option nr 3)


re True / modified SW.. so far no issues with AC motors like the fridge compressor or dinghy davit winch. the only issue i've heard about is tool chargers... my notebook chargers (two of them) are doing just fine...

 

[thoward]

Sounds like a combo unit will work for you then.

I would check in to the Wet Cell vs AGM issue Sky brought up. Everything I have read points to Wet Cells if you can stay up with the maintanence.

I would not replace 1 battery with 4 as it can lead to issues if you ever end up with and/or need to diagnose a dead cell. If you get quality 8Ds you should not have to pull again for at least a couple years if not more.

The Rolls barreries may be the way to go if you can't get them in and out.

 

[DickB]

I recently replaced my 10-year old 2500w Heart (Xantrex) with a new one.
The old was having overheat problems on the charge side. It just didn't
seem to want to charge in a hot engine room. When the engine room cooled, it was fine.

Moving it outside the engine room is an alternative but not real practical as you'll need massive cables to the batteries to accommodate the resistance loss of a longer run. And, as previously said, it needs lots of venting as there's a huge transformer in there. I have a small deck freezer in my fwd stateroom. It cycles on and off all night and doesn't seem to bother people. The inverter buzz makes much less noise, but there's an internal fan that may cycle. The fellow who installed the new inverter reminded me that there are thousands out there, installed in the engine room. And they work fine. So, it wasn't a big decision for me to leave it where it was.

The best thing I ever did with this lash-up was to migrate to 6V deep cycle
batteries. Plenty of amp hours and half the weight of an 8-d. Three are
about the same footprint as an 8-d. So if you have enough room for a pair
of 8-ds, you can perhaps install 6 6V batteries (which is what I have). I
have to run the genny about 3 hrs in the morning and evening to keep the
batteries up. I'm generally only powering the refer, (and ice-maker), deck
freezer, coffee pot in the morning, microwave occassionally and misc lights,
tv, etc. The refer motor worked fine off the old Heart.

Oh, one other advantage of Heart (not sure but Outback may be identical), there are two additional outputs. You can connect say to the start bank and maybe to the gen battery. They won't charge high rates (maybe 20A), but I don't know why you would need anything bigger.

Dick