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Twin battery chargers

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21 hours ago, IanD said:

If your generator is 230Vac output not 48V DC (very likely), you can feed it into the mains input of a Victron Multiplus/Quattro and this will charge the batteries, as well as providing AC for the boat. If you want a big charging current you'll need at least a 5kW combo like the Multiplus II 48/5000 which has the advantage of much lower zero-load power drain than the bigger Quattros as well as being considerably cheaper.

A Multiplus II 48/5000 can accept 50A from AC input (mains or generator up to 11kW), can charge batteries at 70A (3.8kW at typical 55V charging voltage for 16S LiFePO4), and spare generator power is passed through to the boat AC mains. When the genny is off it can provide 5kVA/4kW continuous mains, 9kW for short-term peaks like starting motors. Zero-load power is 18W which is less than 0.5kWh/day to run the inverter.

 

This should be enough for even a boat with a lot of electrical appliances. If it's not enough you can use a bigger Victron Quattro, but these have bigger power drain and have also been rep[orted as often taking more than this -- Quattro 48/8000 and 48/10000 are specified at 60W (1.5kWh/day) but users have reported them taking up to 100W (2.5kWh/day), battery charge currents are 110A and 140A.

 

A better solution would be to parallel up two MPII48/5000 (140A into batteries=7.6kW), this wastes less power and gives you redundancy -- if one dies you can disconnect it and use the remaining one.

 

All this is standard Victron stuff, including adding MPPT controllers for solar (as much as you can fit on the boat); quiet 1500rpm 230Vac generators are widely available, but good ones are not cheap.

 

The big issue is the battery bank, if you want a big enough LiFePO4 one for electric drive without running the generator all the time (probably about 30kWh usable, see below) it's going to be *very* expensive. Most narrowboat hybrids still use 2V traction cell banks for exactly this reason (3x lower cost), though these don't like the very high discharge currents you get with electric boats and series hybrids.

 

30kWh (usable) LiFePO4 : 2@£6650=£13,300

https://www.bimblesolar.com/batteries/lithium-batteries/48v-lithium/BYD-LVL-15.4

30kWh (usable) 2V lead-acid traction : 2@£2280 = £4,300

https://www.bimblesolar.com/batteries/2v/24v-1000ah-traction-battery-bank

 

LiFePO4 is undoubtedly the future and has many advantages (quick charging, no absorption, more efficient) but is still expensive, however prices are dropping every year due to EV usage.

 

You can obviously use a smaller cheaper battery bank but will then have to run the generator more often, and if you ever go out on rivers endurance could then be a problem since the motor can drain the batteries much faster than the generator can charge them, and you might also hit maximum discharge current limits on the batteries.

 

Two MPII 48/5000 and 30kWh LiFePO4 plus an 8kVA 230Vac generator (£8k-10k) will come to something like £25k-£27k, on top of this you need the electric drive motor/controller so probably at least £30k total -- which coincidentally is what you were quoted for a vintage engine 🙂

Edited by IanD
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On 21/11/2020 at 11:28, blackrose said:

 

You must use all outputs from a charger, so in general if a battery charger has 3 and you only have 2 battery banks you should link two of the output terminals and connect that to the biggest bank..

 

That might be true of Mr Sterlings poorly designed chargers but its not the case for either Victron or Mastervolt units...they are quite happy to supply the full output through one terminal or send it to different banks as required. I at present have a Victron charger with three outputs but its only using one of them and splitting the load via a VSR...however should this fail I can then use one of the spare outputs to the second bank...theres no need to connect anything to the third spare output.

Edited by frangar
autocorrect fail!

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33 minutes ago, frangar said:

That might be true of Mr Sterlings poorly designed chargers but its not the case for either Victron or Mastervolt units...they are quite happy to supply the full output through one terminal or send it to different banks as required. I at present have a Victron charger with three outputs but its only using one of them and spilting the land via a VSR...however should this fail I can then use one of the spare outputs to the second bank...theres no need to connect anything to the third spare output.

When not charging are the Victron outputs isolated from each other ?

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10 minutes ago, Loddon said:

When not charging are the Victron outputs isolated from each other ?

According to the spec sheet they are... 3 separate outputs with a common neg. You cant set up different voltage parameters for each output however so the different banks need to be of a same type eg FLA/AGM etc

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8 minutes ago, frangar said:

According to the spec sheet they are... 3 separate outputs with a common neg. You cant set up different voltage parameters for each output however so the different banks need to be of a same type eg FLA/AGM etc

Interesting so no need for any bank splitting.

Mine doesn't have that,  anyway I prefer a VSR as it deals with the solar and twin alternators as well.

 

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15 minutes ago, Loddon said:

Interesting so no need for any bank splitting.

Mine doesn't have that,  anyway I prefer a VSR as it deals with the solar and twin alternators as well.

 

I used to have a diode for splitting the alternator charge and used the different outputs on the charger for the landline charging. Now ive fitted solar I use a Blue Sea VSR in place of the diode so all the banks can charge from the solar and now just have the one connection from the charger., but keep the option of separate outputs in case of failure. What I particularly like about the new Victron charger is that its all controlled via an app on the iPhone/mac/ipad so I can easily see amps/volts on each output.  Ive also fitted a Battery sense module so any wiring loses or temp changes from either the solar or charger are accounted for. 

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41 minutes ago, frangar said:

According to the spec sheet they are... 3 separate outputs with a common neg. You cant set up different voltage parameters for each output however so the different banks need to be of a same type eg FLA/AGM etc

Ah, that's interesting. I went for a single output Victron ip22 charger after struggling to find out how the 3 output version was configured. Had I been able to find that out, I'd have chosen the 3. I suppose that can happen when you're an early adopter!

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9 minutes ago, Sea Dog said:

Ah, that's interesting. I went for a single output Victron ip22 charger after struggling to find out how the 3 output version was configured. Had I been able to find that out, I'd have chosen the 3. I suppose that can happen when you're an early adopter!

I’m very happy with this Phoenix ip43 charger. As it doesn’t have a fan it’s silent. 

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2 hours ago, frangar said:

That might be true of Mr Sterlings poorly designed chargers but its not the case for either Victron or Mastervolt units...they are quite happy to supply the full output through one terminal or send it to different banks as required. I at present have a Victron charger with three outputs but its only using one of them and splitting the load via a VSR...however should this fail I can then use one of the spare outputs to the second bank...theres no need to connect anything to the third spare output.

 

I don't see having to link two output terminals on a charger when installing it 14 years ago as any great hardship.

 

Why do you say Sterling chargers are poorly designed? Mine are both over 14 years old, my Sterling inverter is 15 years old and my alternator regulator is about 13 years old. I've never had a problem with any of it, unlike some of the much newer victron and mastervolt equipment I've read about on here, plus one victron combi on a friend's boat that I helped to uninstall a few years ago because it couldn't handle the voltage fluctuations in the marina. My Sterling equipment was fine.

 

In my experience victron gear has a lot of nice features but also some unnecessary ones making it bit too complex & tempremental and the design isn't really robust enough for installation on boats in the real world.

 

Anyway I'm happy with my Sterling chargers. As long as you're happy with yours that's all that matters.

Edited by blackrose

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27 minutes ago, blackrose said:

 

I don't see having to link two output terminals on a charger when installing it 14 years ago as any great hardship.

 

Why do you say Sterling chargers are poorly designed? Mine are both over 14 years old, my Sterling inverter is 15 years old and my alternator regulator is about 13 years old. I've never had a problem with any of it, unlike some of the much newer victron and mastervolt equipment I've read about on here, plus one victron combi on a friend's boat that I helped to uninstall a few years ago because it couldn't handle the voltage fluctuations in the marina. My Sterling equipment was fine.

 

In my experience victron gear has a lot of nice features but also some unnecessary ones making it bit too complex & tempremental and the design isn't really robust enough for installation on boats in the real world.

 

Anyway I'm happy with my Sterling chargers. As long as you're happy with yours that's all that matters.

Surely theres not much point in having multiple outputs if they arent electrically separate...or cant provide the full output of the charger through each one....thats the sort of thing I mean by a poor design. 

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3 hours ago, IanD said:

A Multiplus II 48/5000 can accept 50A from AC input (mains or generator up to 11kW), can charge batteries at 70A (3.8kW at typical 55V charging voltage for 16S LiFePO4), and spare generator power is passed through to the boat AC mains. When the genny is off it can provide 5kVA/4kW continuous mains, 9kW for short-term peaks like starting motors. Zero-load power is 18W which is less than 0.5kWh/day to run the inverter.

 

This should be enough for even a boat with a lot of electrical appliances. If it's not enough you can use a bigger Victron Quattro, but these have bigger power drain and have also been rep[orted as often taking more than this -- Quattro 48/8000 and 48/10000 are specified at 60W (1.5kWh/day) but users have reported them taking up to 100W (2.5kWh/day), battery charge currents are 110A and 140A.

 

A better solution would be to parallel up two MPII48/5000 (140A into batteries=7.6kW), this wastes less power and gives you redundancy -- if one dies you can disconnect it and use the remaining one.

 

All this is standard Victron stuff, including adding MPPT controllers for solar (as much as you can fit on the boat); quiet 1500rpm 230Vac generators are widely available, but good ones are not cheap.

 

The big issue is the battery bank, if you want a big enough LiFePO4 one for electric drive without running the generator all the time (probably about 30kWh usable, see below) it's going to be *very* expensive. Most narrowboat hybrids still use 2V traction cell banks for exactly this reason (3x lower cost), though these don't like the very high discharge currents you get with electric boats and series hybrids.

 

30kWh (usable) LiFePO4 : 2@£6650=£13,300

https://www.bimblesolar.com/batteries/lithium-batteries/48v-lithium/BYD-LVL-15.4

30kWh (usable) 2V lead-acid traction : 2@£2280 = £4,300

https://www.bimblesolar.com/batteries/2v/24v-1000ah-traction-battery-bank

 

LiFePO4 is undoubtedly the future and has many advantages (quick charging, no absorption, more efficient) but is still expensive, however prices are dropping every year due to EV usage.

 

You can obviously use a smaller cheaper battery bank but will then have to run the generator more often, and if you ever go out on rivers endurance could then be a problem since the motor can drain the batteries much faster than the generator can charge them, and you might also hit maximum discharge current limits on the batteries.

 

Two MPII 48/5000 and 30kWh LiFePO4 plus an 8kVA 230Vac generator (£8k-10k) will come to something like £25k-£27k, on top of this you need the electric drive motor/controller so probably at least £30k total -- which coincidentally is what you were quoted for a vintage engine 🙂

This is my point. I know £30k is a lot of money for a drive train but I just really fancy the idea of quiet running whenever possible. Thank you. 

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21 hours ago, frangar said:

I’m very happy with this Phoenix ip43 charger. As it doesn’t have a fan it’s silent. 

The ip22 charger has a fan, but it also has a night mode which adjusts the output enough to keep it from cutting in.  That said, I've never selected it as the fan has never cut in anyway!.

Edited by Sea Dog
Autocorrect sp

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