Solar Upgrade verse Running the Generator

[john61ct]

Originally Posted by Exile

devote all 6 to the house bank (675ah vs. my current 510ah) and modify the box for the genset start batt. to accommodate a G31 for both genset & main engine starting.

Yes, just have a self-jumpstarting feature whether you combine for charging or not.

Originally Posted by Exile

Is my understanding correct about these so-called "golf cart" batts. that they can endure a lot more abuse, i.e. repeated charges to only 80%, etc.?

True deep cycle more so than dual purpose, and FLA more so than AGM.

However above are the formula for getting to 100% every cycle, and that will give far more longevity than just once in a while.

The only lead batt that seems to truly not mind PSOC abuse is Firefly Oasis.

[Exile]

Originally Posted by john61ct

Yes, just have a self-jumpstarting feature whether you combine for charging or not.

Not sure on the terminology, but I have what I call cross-over relays which I can engage to boost the start batts. with amps from the house bank. In theory (based on my engine manual specs), my same Lifeline 24 for the genset could also start the engine, but that's assuming 68F & no resistance from cabling I'm sure. With the house bank relay as backup it could work but maybe a bit dicey.

True deep cycle more so than dual purpose, and FLA more so than AGM.

However above are the formula for getting to 100% every cycle, and that will give far more longevity than just once in a while.

I thought AGM's had less resistance than FLA's so getting from 80-100% was faster. Downside is if you don't get to 100% with some frequency AGM's will die faster. Btw, I've read that the T-125/145's have thicker plates to produce the add'l amps in basically the same sized case so won't have as many cycles as the T-105's.

The only lead batt that seems to truly not mind PSOC abuse is Firefly Oasis.

I'll certainly be looking for different sizes to come out before I have to replace my Lifelines.

[Exile]

Originally Posted by Kenomac

After reading all this, it seems that by chance and doing a little homework I got things right. Invisible 450w solar capable of charging 100% while at anchor, 10kw generator with two Mastervolt chargers 125w and an 85p extra 24v alternator, for a 450ah Trojan 105 bank.

When the time comes, the Trojans will be replaced with same. 'Just finishing up season six in three weeks.

WOW! Post #8000.

Your battery bank sizing/capacity might explain your recent meltdown when you tried to run the h/w heater off the batts/inverter. Seemed like all the numbers added up but maybe the batts. couldn't handle that large a load all at once. Has everything now recovered, incl. the Smartgauge?

[Kenomac]

Originally Posted by Exile

Your battery bank sizing/capacity might explain your recent meltdown when you tried to run the h/w heater off the batts/inverter. Seemed like all the numbers added up but maybe the batts. couldn't handle that large a load all at once. Has everything now recovered, incl. the Smartgauge?

Everything recovered within 1/2 hour from the time I made the change. I won't be changing over to a larger bank or lithium just to have piping hot water on demand 24/7/365. Our complete system is geared towards cruising in the Med, other locales probably have other needs.

I suggest you place your boat over here, copy our system then enjoy.

No plans to turn our boat into a solar farm or increase the size of the bank.

[john61ct]

Originally Posted by Exile

Not sure on the terminology, but I have what I call cross-over relays which I can engage to boost the start batts with amps from the house bank.

Sounds fine, just do test it all, many ways to work it if need be.

Originally Posted by Exile

I thought AGM's had less resistance than FLA's so getting from 80-100% was faster. Downside is if you don't get to 100% with some frequency AGM's will die faster.

Actually the higher CAR speeds things up more in the 50-80% range, still need ~5 hours more for the low-amps long tail, which is why the solar is so essential when away from shore.

And yes if going to be unable to coddle properly, FLA will be a bit more robust, IMO chronic PSOC means going cheap GCs like Sam's Duracell, or right up to Firefly or even LFP, not bother with in-between.

Don't forget with that size an AGM bank charging current of 120A **plus concurrent loads** will be **bare minimum** for bank longevity, 200+A would not be wasted.

FLA would get by with 100A.

[skipgundlach]

Long ago above, but yesterday, someone said tax credit for LiFePOs

Yes, and solar panels and wind generators and all the attendant costs to install and change over systems, AND FLAs or any other part of a separate green system, including upgrades.

But you have to be in a tax bracket to take advantage of it, or it's worthless, or will take you as long as the life of what you just put in to recover it...

[ranger58sb]

Originally Posted by Exile

Compared specs for my 8D's vs. T-105's and answered a few of my own questions. The T-105's are about the same length, slightly narrower, and slightly taller, so two 6v's should fit in each box made for my 8D's just fine. 225ah vs. 255ah for the Lifelines, although there is also a T-125 (240ah) & a T-145 (260ah) that are slightly heavier & taller (and presumably more expensive). Trojan also offers a "one point" watering system which sounds like a plus. I could potentially devote all 6 to the house bank (675ah vs. my current 510ah) and modify the box for the genset start batt. to accommodate a G31 for both genset & main engine starting.

Ummm... thought I remembered 3x GCs would fit in the same space as a single 8D.

??

If so, and if you have two 8D boxes, that could be 6x GCs, ~660-Ah... And if you have 3 boxes, could be 8 GCs, plus room for an engine/genset start battery. (Odyssey G34M AGM?)

But I may be mis-remembering.

-Chris

[a64pilot]

Originally Posted by Exile

Is your 15 amps estimate while under sail or at anchor/mooring? This is why it doesn't make that much sense to me to install even a single 100w panel which is all I feel I have room for right now. Fine for leaving the boat at anchor to keep the batts. up after a full charge, but I'm not sure it would contribute enough to offset house loads (at anchor) to make it worthwhile, even though those loads are typically quite modest.

Worst case number, with Satellite TV system on and TV on, with fridge compressor running, several lights, radio, autopilot, inverter etc.
Average consumption is around 10 amps I think. I do not yet have an amp counter, but overnight consumption of a 660 AH bank according to the smart gauge is 15% SOC, so assuming the bank is really 660 AH, 100 AH overnight. It's not 660, but I have no idea what it is really.

Any Solar helps, it may not be enough to carry the load fully, but it helps. Think of carrying sail when motoring, the sails may only carry some load, but allow a RPM reduction of the engine, which helps.

However if you don't mind the windage and appearance, with a little creativity, I think I could put more than 100W on a canoe.

Some can't get over what they look like. Me, I'm a form follows function guy. I flew Apaches, nothing is uglier or more functional than an Apache.

[sailorboy1]

Damn, if I don't watch tv/DVD i only use 60-75 ah in a 24 hour day while at anchor

[a64pilot]

Originally Posted by sailorboy1

Damn, if I don't watch tv/DVD i only use 60-75 ah in a 24 hour day while at anchor

That is why you can get by with a few hundred watts of Solar, and why I need a Kilowatt. It's why when someone asks how much Solar do I need, the answer is, it depends.
My fridge alone uses more power than you do. It's a BD-80 compressor, large and not well insulated. Then out of laziness I often leave the Sat dome on all night, and the 2800 W inverter on 24/7.

It's a lot like a financial budget, you learn to stay within your income or cruising soon ends. Power production is like money, you can't spend more than you have, or not for long anyway.

[Exile]

Originally Posted by Kenomac

Everything recovered within 1/2 hour from the time I made the change. I won't be changing over to a larger bank or lithium just to have piping hot water on demand 24/7/365. Our complete system is geared towards cruising in the Med, other locales probably have other needs.

I suggest you place your boat over here, copy our system then enjoy.

No plans to turn our boat into a solar farm or increase the size of the bank.

You have the genset so why would you? Your temporary electrical meltdown probably helps explain why john61 and others talk about how trying to run high consumption AC appliances isn't very practical off DC/inverter, even if the math does support that in theory. I don't completely understand it but must have something to do with a disproportionate amt. of voltage drop in LA batts. when hit with big loads all at once. Mastervolt claims its inverters can compensate for a lot of that, so that points even more to your battery bank. Besides, it wouldn't be good for your genset to only run it when you need to charge batts., which is why I'll probably go with a 110v watermaker when the time comes.

This has been an educational thread and hopefully the OP doesn't mind all the drift. Our boat electrical systems seem so interconnected with other issues that need to be weighed that it all seems pretty relevant. I guess you could call the broader theme "how to best determine solar panel sizing on a boat with a genset and combo of DC & AC appliances."

[Exile]

Originally Posted by ranger42c

Ummm... thought I remembered 3x GCs would fit in the same space as a single 8D.

??

If so, and if you have two 8D boxes, that could be 6x GCs, ~660-Ah... And if you have 3 boxes, could be 8 GCs, plus room for an engine/genset start battery. (Odyssey G34M AGM?)

But I may be mis-remembering.

-Chris

For some reason I thought each one of my 8D boxes could hold more than 2 6v GC's as well, but apparently not according to the Lifeline & Trojan websites.

Lifeline 8D: L 20.76" W 10.89" H 8.64"

Trojan T-105: L 10.30" W 7.11" H 11.07"

I think I can find another 2.5" or so of hgt., can shim for the narrower width, and am ok on length. So that would be a total of 6 GC's for 675ah, although using T-145's would add another 105ah for 780ah total, albeit at greater cost & potentially fewer cycles. The T-105's seem to be the most popular sellers and so are quite a bit cheaper than both the T-145's & the T-125's.

The start battery would use my existing BEP VSR so I'm not sure if I could use a different type (AGM) for that.

[Kenomac]

Originally Posted by Exile

You have the genset so why would you? Your temporary electrical meltdown probably helps explain why john61 and others talk about how trying to run high consumption AC appliances isn't very practical off DC/inverter, even if the math does support that in theory. I don't completely understand it but must have something to do with a disproportionate amt. of voltage drop in LA batts. when hit with big loads all at once. Mastervolt claims its inverters can compensate for a lot of that, so that points even more to your battery bank. Besides, it wouldn't be good for your genset to only run it when you need to charge batts., which is why I'll probably go with a 110v watermaker when the time comes.

This has been an educational thread and hopefully the OP doesn't mind all the drift. Our boat electrical systems seem so interconnected with other issues that need to be weighed that it all seems pretty relevant. I guess you could call the broader theme "how to best determine solar panel sizing on a boat with a genset and combo of DC & AC appliances."

When I run the generator for 45 minutes or so on days my wife is here and we're not moving, is to heat hot water which apparently uses a ton of juice while the batteries are also being charged. Watermaker and cooking all at the same time.

[john61ct]

Originally Posted by Exile

The T-105's seem to be the most popular sellers and so are quite a bit cheaper than both the T-145's & the T-125's.

The start battery would use my existing BEP VSR so I'm not sure if I could use a different type (AGM) for that.

Just check your volts are within spec for the starter. But I'd go FLA on that too unless AGM required.

T-105 is really "the standard", IMO best stick to that unless real need dictates otherwise.

[Exile]

Originally Posted by a64pilot

Worst case number, with Satellite TV system on and TV on, with fridge compressor running, several lights, radio, autopilot, inverter etc.
Average consumption is around 10 amps I think. I do not yet have an amp counter, but overnight consumption of a 660 AH bank according to the smart gauge is 15% SOC, so assuming the bank is really 660 AH, 100 AH overnight. It's not 660, but I have no idea what it is really.

Any Solar helps, it may not be enough to carry the load fully, but it helps. Think of carrying sail when motoring, the sails may only carry some load, but allow a RPM reduction of the engine, which helps.

However if you don't mind the windage and appearance, with a little creativity, I think I could put more than 100W on a canoe.

Some can't get over what they look like. Me, I'm a form follows function guy. I flew Apaches, nothing is uglier or more functional than an Apache.

I don't mind the aesthetics of solar panels so much. It's more about windage, clutter & sharp corners for me. Ken's set-up on top of his bimini is appealing, but I typically prefer having my bimini down when sailing (personal thing). This is why I might consider a Watt&Sea while underway and maybe a large, cheapo flexible panel with grommets that I can hang over the boom at anchor. The cruising version of the W&S is about $5K but I believe that's more or less all-inclusive (comes w/reg & bracket) and puts out serious amps provided you're going at least 6-7 kts., speeds that are usually easily achievable on my 47'er. IIRC, I can use the same MPPT controller that I would use for the panel.

My amp draw while underway is closer to 12ah w/AP, and 5-6 at anchor. For better or worse (haven't decided yet), my fridge & freezer run off 110v (holding plates), unless I'm motoring when I can use the engine drive compressor (old school set-up from 1980's). That might need to be converted to 12v but that's a whole other issue . . . .