diy solar

diy solar

Help with first steps

grakker

New Member
Joined
Mar 5, 2021
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7
I've been reading this forum and others for weeks/months and I feel like I'm trying to drink from a firehose. Hopefully someone can give me a little advice on where to start.

I have an old, small (26ft) sailboat. One house battery, one start. Both charged from 110v shore charger. Also have a little 50 watt panel that plugs into a cigarette adapter and adds...something.

I would like to update storage, as well as be ready to add solar and more batteries in the next year or so, if not sooner.

I'm going to go with LiFePo4 battery. Chins or whatever. I have to get a new charger because my old Xantrax doesn't do Lithium.

I guess my questions are:
  1. Do I just buy the battery and a new charger, and then just deal with solar later? Or is there a charger that also works with solar? Is that even a good idea?
  2. I'd like to go 24v. When the engine goes I'd like to go electric, but that'll be awhile as the engine is in good shape. I might be stupid with wanting to go with 24v now. Do I need to replace the alternator on the engine to charge 24v battery? The starting battery is 12v, is doing a 24v house battery needlessly complicating things?
I'm just worried that I'll think it's something easy and then find myself 4 months later still trying to fix, or even figure out, what is going on. Anyone who can give me a very basic place to start is very appreciated.
 
I've been reading this forum and others for weeks/months and I feel like I'm trying to drink from a firehose. Hopefully someone can give me a little advice on where to start.

I have an old, small (26ft) sailboat. One house battery, one start. Both charged from 110v shore charger. Also have a little 50 watt panel that plugs into a cigarette adapter and adds...something.

I would like to update storage, as well as be ready to add solar and more batteries in the next year or so, if not sooner.

I'm going to go with LiFePo4 battery. Chins or whatever. I have to get a new charger because my old Xantrax doesn't do Lithium.

I guess my questions are:
  1. Do I just buy the battery and a new charger, and then just deal with solar later? Or is there a charger that also works with solar? Is that even a good idea?
  2. I'd like to go 24v. When the engine goes I'd like to go electric, but that'll be awhile as the engine is in good shape. I might be stupid with wanting to go with 24v now. Do I need to replace the alternator on the engine to charge 24v battery? The starting battery is 12v, is doing a 24v house battery needlessly complicating things?
I'm just worried that I'll think it's something easy and then find myself 4 months later still trying to fix, or even figure out, what is going on. Anyone who can give me a very basic place to start is very appreciated.
Do you charge your current battery via the alternator?
 
The batteries seem to charge up when I motor, but to be honest, I just turn on the engine to get in and out of the slip and haven't run it a lot.
 
The batteries seem to charge up when I motor, but to be honest, I just turn on the engine to get in and out of the slip and haven't run it a lot.
Ok so you have the ability to charge both your starter and house batteries via alternator.
I'm going to assume that your starter and house batteries are 12 volt lead acid.
You need to check your alternator to see what current it is rated for.
Then check to see how much unused capacity you have.
An ac/dc clamp meter with max current feature will help you determine this.
Its a good tool to have because knowing beats guessing.
To charge a 24 volt battery from a 12 volt alternator I suggest something like this.
 
I'll take a look at what the alternator is putting out. Right now it's in the yard getting some repairs that showed up on the survey. Supposed to be splashing back the end of this week. And yes, the two batteries are lead acid.
 
Do I just buy the battery and a new charger, and then just deal with solar later? Or is there a charger that also works with solar? Is that even a good idea?
There are things called hybrid inverters, growatt is a mainstream decent brand that I am going with shortly. These units can take in shore power to charge your batteries while docked, they can take in solar power to charge your batteries and can also invert the power up to normal house current.

Do I need to replace the alternator on the engine to charge 24v battery?
It'd just be a 24v alternator, to do it the right right way, the engine doesn't care what it spins. It does work harder the more current is drawn on the alternator as the field between the rotor and stator is getting stronger but for your application the hardest thing to do would be to find a 24v alternator that mounts up to your sailboat engine. Or the dc-dc charger.
The starting battery is 12v, is doing a 24v house battery needlessly complicating things?
I would say yes right now because your whole boat is setup for 12v. Starter, alt, gauges, lights, bilges etc.

Replacing your two batteries now with lith would be a great start that can be expanded on later.
Charging that new bank from your alternator I'm not sure of and haven't done any research on as I don't foresee myself doing it, anytime soon at least. But just type in 'alternator' in the search function on the top right and I almost guarantee there's something helpful in the first 5 threads.

Hope this helped some.
 
There are things called hybrid inverters, growatt is a mainstream decent brand that I am going with shortly. These units can take in shore power to charge your batteries while docked, they can take in solar power to charge your batteries and can also invert the power up to normal house current.
Thank you, that is actually what I was looking for. Do you know of a reputable source to buy one? I looked on Amazon and all I could see are 24v and 48v inverters. Sounds like I should be able to change the charger to an inverter/charger first, and then switch out the batteries, then move on from there.
 
Does this one seem OK for a 12v system? Doesn't seem like a lot of money and from my look at it, it seems to do everything I need. Granted I'll have to get a new one when/if I go to 24v but that can be a ways down the road. If ever.


Looks to me that I could start with this and then build around as time/needs dictate. I'm just so wary due to my lack of experience.
 
Thank you, that is actually what I was looking for. Do you know of a reputable source to buy one? I looked on Amazon and all I could see are 24v and 48v inverters. Sounds like I should be able to change the charger to an inverter/charger first, and then switch out the batteries, then move on from there.
Yea most are 24 and 48v. They're great if you're like me with a complete blank slate but when trying to stick one in something like a boat where it's already set up for 12v it's a little more involved.
 
Does this one seem OK for a 12v system? Doesn't seem like a lot of money and from my look at it, it seems to do everything I need. Granted I'll have to get a new one when/if I go to 24v but that can be a ways down the road. If ever.


Looks to me that I could start with this and then build around as time/needs dictate. I'm just so wary due to my lack of experience.
Not bad versus nothing but 1k is not that much. It looks like those are meant to be stacked and built upon each other.
 
Not bad versus nothing but 1k is not that much. It looks like those are meant to be stacked and built upon each other.
I'm having trouble finding a 12v integrated unit that has a higher inverter. I don't have a lot of draw, but I'm guessing if I can't find one with a bigger inverter, I may just have to add a separate inverter later. If I find some place to fit a microwave or something.
 
I'm having trouble finding a 12v integrated unit that has a higher inverter. I don't have a lot of draw, but I'm guessing if I can't find one with a bigger inverter, I may just have to add a separate inverter later. If I find some place to fit a microwave or something.
That's because when you get into drawing more and more amps the wire gets so much thicker at 12 volts it's not practical.
This one k unit wouldn't be terrible for you you can do a decent amount of stuff with a thousand Watts just have to really be conscious of what's turning on at the same time.
 
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That's because when you get into drawing more and more amps the wire gets so much thicker at 12 volts it's not practical.
This one k unit wouldn't be terrible for you you can do a decent amount of stuff with a thousand Watts just have to really be conscious of what's turning on at the same time.
Thank you so much for taking the time to reply. I ordered the 12v one I linked to. $711 with tax/shipping. I'm looking forward to getting started and learning some stuff. Thanks again.
 
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