DC to DC charger - not needed for boats with proper alternators.

[Simi 60]

I'm not buying in euro

[CaptainRivet]

Originally Posted by Simi 60

I'm not buying in euro

Convert currency, doesn't change anything.

[Simi 60]

Originally Posted by CaptainRivet

A wakespeed costs 600Euro and 2x Sterling DC2DC is about the same on sale, not on sale more expensive. And even if 200 more expensive thats nothing in boat bucks...
.

I bought mine on sale - I buy near everything on sale
And $200 buck is $200 bucks, it's not nothing - Wakespeed $400 difference to our 2 dc2dc
Realising that Is how I stopped work in my 40's

The difference is the wakespeed is regulating it dynamically and really regulating the alt reliably to its max output possible and on very hot days this might be even cut back to 80% while on colder maybe only 40%. How this really is the wakespeed will tell you...and adapt dynamically and reliable to it for the same amount of money

Not so the DC2DC is fixed at 70% derating without taking the actual root cause alternatur temp into account. And on very hot days that might be even too less and you fry them a 2nd time.its playing lottery.

.

Summer, winter, our ER is the same temp so this is irrelevant

Or do/did you have constant temp monitoring on the alternator over a longer periode to see its fix 70% derating will do it independently from surrounding temps.

Yes I do have temp monitoring on my alt
Probe 2 off of a $100 engine guard temp alarm
The other is on exhaust elbow

But still then the wakespeed solution is superior for the same money spent

Says you
And it's not the same money spent
It's more expensive

And if it fails I have none
If one of my dc2dc charger fails I still have one

[Simi 60]

Originally Posted by CaptainRivet

Convert currency, doesn't change anything.

Bollocks
Freight as an example

[CaptainRivet]

Originally Posted by Simi 60

I bought mine on sale - I buy near everything on sale
And $200 buck is $200 bucks, it's not nothing - Wakespeed $400 difference to our 2 dc2dc
Realising that Is how I stopped work in my 40's

.

Summer, winter, our ER is the same temp so this is irrelevant


Yes I do have temp monitoring on my alt
Probe 2 off of a $100 engine guard temp alarm
The other is on exhaust elbow


Says you
And it's not the same money spent
It's more expensive

And if it fails I have none
If one of my dc2dc charger fails I still have one

Thanks for taking the time to state facts and details about your setup.
Now its clear that your surroundings conditions of install are an extreme exception from the average eg same Er temp in winter and summer so you have a fixed derating of 70%.
Don't know any cruising boat where this is the case but there are always exceptions.
So it clear for newbees or other with a basic knowledge that think about LFP install if they read it.

I retired with 49 and doing world circum, so i know a bit that 200buck is 200bucks, otherwise that wouldn't been possible either. But 200bucks for a top notch solution to prevent 5-10times the damage is well spend boat money and nothing in relation to yearly spend on it.

As the are not important to you and obviously you prefer cheap solution and have a constant environment it would have been much cheaper to put a resistor into the field line of the alternator and limit it this way to 70%.
Much cheaper then 2x Dc2DC and less that can break. You are monitoring them anyhow from temps.

If the wakespeed fails you could fix that with the resistor very quickly too but if a wakespeed fails you have in 99% a much bigger problem eg lighting strike...

[CaptainRivet]

Originally Posted by Simi 60

Bollocks
Freight as an example

Prices for a wakespeed are quite equal in europe and US, they weight nothing and contain nothing that rises the cost of shipping. Also no high import taxes.

Compared to DC2DC Sterling, they are quite heavy and shipping is a bigger part of total price, so surpriced you got them so cheap.

[Simi 60]

Originally Posted by CaptainRivet

Thanks for taking the time to state facts and details about your setup.
Now its clear that your surroundings conditions of install are an extreme exception from the average eg same Er temp in winter and summer so you have a fixed derating of 70%.
...

It's a well ventilated and spacious ER with full standup headroom.
15c to 38c outside temp seems no make no difference inside - after a full days running ER temp over the past 7 years has always been 38c.


.

But 200bucks for a top notch solution to prevent 5-10times the damage is well spend boat money and nothing in relation to yearly spend on it.

You keep saying $200 when it's actually quite a bit more

$400+ is the price difference here today for 1 Wakespeed vs 2 X 24v @ 35amp dc2dc sterling.
Then if going Wakespeed, I also need a alternator protection device , another $220
And I also need to keep the starts charged so a dc2dc charger at $375

Already we are at $1000 more for Wakespeed vs dc2dc X 2.

And if throwing money into the fire why stop there, might as well get a bigger better alt to take advantage of the wakespeed
So another $7000 on a Delco 55si

Anyway - I'm past caring
You do what you do, I'll do what I do.

[hjohnson]

Originally Posted by Simi 60

Then if going Wakespeed, I also need a alternator protection device , another $220

If your Wakespeed gets its command from the BMS, then there's no need for an alternator protection device. If the BMS throws an alarm before a disconnect, the wakespeed will go into a standby state and shut down the field, eliminating the need for a shutdown device. In two years, I've never come close to a disconnect event. If the BMS is unhappy with the state of affairs, which only happened the first time I charged my bank (I didn't bother to top-balance manually) it just commands the charging system to limit the charge current to whatever. It works a treat.

And I also need to keep the starts charged so a dc2dc charger at $375

Well, you only need one small one, since your starter battery never discharges much. 18A victron DC-DC charger is $192. That's what I'm using, and pretty much my starter battery never leaves float stage. But you're also not buying the two sterlings, so that's a net savings.

What your sterlings don't do is give you the ability to adjust engine load based on RPMs. Say I'm putt-putting into the marina at 1000rpm, I really don't want to load my engine down with a huge alternator load. I can program the wakespeed to cap the field based on RPMs.

[Simi 60]

Originally Posted by hjohnson

If your Wakespeed gets its command from the BMS.....

.
If buts maybes
Out of my league
Now I need to pay a bloody sparky several hundreds of dollars or more on top to come and do an install.

I'll stick with the simple dc2dc thanks
Easy install

Well, you only need one small one, since your starter battery never discharges much. 18A victron DC-DC charger is $192. That's what I'm using, and pretty much my starter battery never leaves float stage. But you're also not buying the two sterlings, so that's a net savings.

Nope
24v starts
$400+ for Victron

What your sterlings don't do is give you the ability to adjust engine load based on RPMs. Say I'm putt-putting into the marina at 1000rpm, I really don't want to load my engine down with a huge alternator load. I can program the wakespeed to cap the field based on RPMs

.

We have a 14 litre nta855m Cummins
Load from dc2dc chargers is nothing and 1150 is our cruising speed

But, you do what you do.
I'll do what we have done.

[Fuss]

Originally Posted by CaptainRivet

For sure he doesn't pay. Again just blabla.
Well and i bet he put temp sensor but didn't use them to properly manage the alternator.
At the end we will figure an undersized cable and corroded connection saved his alternator and the 140 degrees C was a wrong measurement.
The same as his engine has in the end a 2,5kw starter that needs just needs 400-500A surge capabilities and his engine manufacturer hugly overspeced by stating you need a 1400CCA battery. But Fuss stating the EVE cells can do 1400cca by pulsing and other bs he wrote. So it was surge peaks of max 500A in reality which is below spec of 2C peak why 4x280AH EVE sells survived that 9 month...
Was always the same reason of a 2nd faulty installation issue that saved guys like him from equipment frying or boat burning down.

Really, you want to say that, the 1500 hr old alternator, putting out 24v 150ah has been running all this time with an undersized cable and a corroded connection that’s why it didn’t burn out.
I think you should stop giving advice on this forum captainrivet.

[Uncle Bob]

Originally Posted by Fuss

Really, you want to say that, the 1500 hr old alternator, putting out 24v 150ah has been running all this time with an undersized cable and a corroded connection that’s why it didn’t burn out.
I think you should stop giving advice on this forum captainrivet.

Hey, come on, the entertainment value in these posts is well worth it.

[hjohnson]

Originally Posted by Simi 60

.
If buts maybes
Out of my league
Now I need to pay a bloody sparky several hundreds of dollars or more on top to come and do an install.

I'll stick with the simple dc2dc thanks
Easy

Running a network cable and flipping a couple of options in a configuration file is out of your league? I fear for the state of your boat. It took me all of 20 minutes to get it going, including running a pair of network cables half way across the boat.

[Simi 60]

Originally Posted by hjohnson

Running a network cable and flipping a couple of options in a configuration file is out of your league? I fear for the state of your boat. It took me all of 20 minutes to get it going, including running a pair of network cables half way across the boat.

Is an attempt at belittlement the best you can offer?
.
Appears I need a cerbo to do all that stuff, not needed, not wanted, extra expense again

Wakespeed proving to be more expensive every time a fanboy makes a post

Wakespeed also say it's a complex system and should be installed by a pro. (See pic)
I did look into fitting one before deciding to go dc2dc but several months later, no one has replied to my emails and I wasn't about to chase them up.

Sterling UK on the other hand got back to me next day and have replied to several emails since.

As a full time cruiser actual technical support when needed wins.




.

[CaptainRivet]

Originally Posted by Simi 60

Is an attempt at belittlement the best you can offer?
.
Appears I need a cerbo to do all that stuff, not needed, not wanted, extra expense again

Wakespeed proving to be more expensive every time a fanboy makes a post

Wakespeed also say it's a complex system and should be installed by a pro. (See pic)
I did look into fitting one before deciding to go dc2dc but several months later, no one has replied to my emails and I wasn't about to chase them up.

Sterling UK on the other hand got back to me next day and have replied to several emails since.

As a full time cruiser actual technical support when needed wins.




.

You want it simple and cheap.
Derate alternator to 70% with resistor on field wire.
Take an Victron argofet splitting diode, input alternator and connect output LFP and starter
Simple, cheap and fits your needs.
Your BMS shuts the alternator down when LFP full, the lead is cut off and surge protection, the voltage drop on argofet is enough to reduce voltage so its not to high for LFP.
Alternator does bulk, absorption done by solar.
You don't need 3 stage alternator charge on LFP and LFP takes itsself whats needed.
To make it perfect you could use a small solar panel with small mppt connected directly to starter to constantly trickle charge your starters, works also whennengine not running and a 50W solar you can fit on your cruiseship easily.
I am no wakespeed fanboy at all, find it outrages expensive but there are cases it simply fits perfectly and allows for perfect adjustment which wouldn’t be possible with any other regulator. And yes then i would install it.
I agree in your case with stable ER and therefor alt temps a wakespeed is overkill as you don't need any of its standalone feature.
If your ER/Alt temps are much more variable and depend on water and air temps, like most cruiser boats i know, the wakeapeed would be the best solution here, thats why i suggested it in first place.

[CaptainRivet]

Originally Posted by Fuss

Really, you want to say that, the 1500 hr old alternator, putting out 24v 150ah has been running all this time with an undersized cable and a corroded connection that’s why it didn’t burn out.
I think you should stop giving advice on this forum captainrivet.

Read it again