Battery charger questions

[Alex_Blackwood]

I'm away cruising for the next six weeks, so looking for a temporary fix

It’s this bit that confused me. To my simple mind it sounds like he’s after a 240v battery charger, that has a 240v output that a 4-gang extension could be plugged into.

Yep, that's it.

So where does the charger get its supply from? If cruising I assume at sea and no shore power?

 

[ylop]

So where does the charger get its supply from? If cruising I assume at sea and no shore power?

Assuming that the OP is not totally stupid and doesn't think he has invented some form of perpetual motion machine do you not think its possible that his definition of "away cruising" and yours might be slightly different?

e.g. someone off cruising round britain, the med or the western isles for 6 weeks popping into marina's once a week would still be away cruising, and likely not wanting to spend time tied up doing boat surgery to install a proper shore power installation. Sometimes people write posts in a relatively relaxed way rather than expecting every word to be forensically directed but the clue was probably in the OP: "...but sunless windless days in marinas are something else..."

 

[PaulRainbow]

Assuming that the OP is not totally stupid and doesn't think he has invented some form of perpetual motion machine do you not think its possible that his definition of "away cruising" and yours might be slightly different?

e.g. someone off cruising round britain, the med or the western isles for 6 weeks popping into marina's once a week would still be away cruising, and likely not wanting to spend time tied up doing boat surgery to install a proper shore power installation. Sometimes people write posts in a relatively relaxed way rather than expecting every word to be forensically directed but the clue was probably in the OP: "...but sunless windless days in marinas are something else..."

Yet he asked for a battery charger with a 13A socket to plug his 4 way cable into. How does that work ?

Does he mean a 13A plug to plug into his 4 way cable ?

Does he mean an inverter/charger ?

 

[webcraft]

Yet he asked for a battery charger with a 13A socket to plug his 4 way cable into. How does that work ?

Does he mean a 13A plug to plug into his 4 way cable ?

Does he mean an inverter/charger ?

It's purely a question of cable routing, nothing more than that. 16A cable to the charger in the cockpit locker then a single lead from there into the boat.

However, I think I have found a route to plug the charger in inside the boat. Have ordered a 15A charger with a longer mains cable which I will pick up in Shetland.

Apologies for being confusing.

 

[webcraft]

I doubt you’ll find a battery charger with a 13a 240v output.

I have the same charger on boat as Sandy (above) but for the car I bought one of these:

Amazon.co.uk

Swap out croc clips for ring terminals and leave plug somewhere easily accessible perhaps. It does indeed put out 15a, has a LiFePo setting (for future update if needed) and is actually surprisingly good.

I got that 15A charger and plan to wire it directly to the batteries as suggested.

I note one of the safety warnings is "charging the batteries with vehicles connected is not suggested, it may have potential damage to the car electronics during the desulphation stage"

Bollocks or not?

 

[Tranona]

Yes.

 

[webcraft]

Yes.

Yes it's bollox or yes it's not bollox?

Brevity is good, but not to excess.

 

[Tranona]

If it was not I would have said no! Anyway you are unlikely to do the desulphation bits and your boat does not have the sort of electronics that a car has. Simple explanation here ctek.com/uk/news-archive/looking-after-your-car-battery-as-you-come-out-of-quarantine?srsltid=AfmBOoq-BR2z-1XxZNAwyP566ni3H3Yjjd8arMspr-XsAg1684bP5M0Q

 

[BabaYaga]

Anyway you are unlikely to do the desulphation bits and your boat does not have the sort of electronics that a car has.

I think you will find that desulphation is part of the normal cycle, as a first stage. The pulsing (up to 15.8V) only lasts for a few seconds though. You may have been thinking about the recond mode, which is something else. I agree that the brief desulphation pulsing is probably not harmful to common boat equipment.

 

[Seamonk]

Agreed.

Define the problem and get the right solution.
On our boat that is 3 separate Victron's, one for each battery bank. It is on continously when shorepower is available, even during winter while on the hard. The chargers are Bluetooth connected, so can be monitored and managed remotely. The charger turns to storage mode when it detects no use and virtually keeps the batteries topped during winter for like £10.

View attachment 196482

I’ve been wondering about separate chargers for each bank versus a single “multi-bank” charger. What made you think this was the right approach? One advantage I can see is that the charger output can be matched to the size of the bank. On the down side, seems like it would take up a lot of space. I’m also wondering how ACRs (auto charge relays) might get confused by multiple units amping up different circuits.

 

[ChromeDome]

I’ve been wondering about separate chargers for each bank versus a single “multi-bank” charger. What made you think this was the right approach? One advantage I can see is that the charger output can be matched to the size of the bank. On the down side, seems like it would take up a lot of space. I’m also wondering how ACRs (auto charge relays) might get confused by multiple units amping up different circuits.

First, the existing multi-channel charger stopped working. It was only pseudo-multi because it had separate outputs, but in reality it was a single charger inside. So there was no intelligent (staged) charging for individual battery banks.

Next, I decided on my budget and my requirements (need/nice to have).

The choice was made after careful consideration, so it is the solution that suits my boat and my requirements. It is by no means certain that this solution will suit you or others.


Nevertheless, for inspiration:

I have different battery banks, with batteries for starting and consumption. Some are dedicated starter batteries, others for deep cycle discharge. And I have a separate bow thruster battery that is kept charged but is disconnected via a relay when the thruster is used to avoid the consequences of the enormous power drain that can otherwise cause everything else to shut down momentarily. And restart. Repeatedly with each touch of the thruster switch.

After collecting data and comparing, I decided to make a removable panel connected with waterproof connectors so that servicing can be accessed at any time, including other things near the panel. Victron was selected, also due to dealer proximity.

It's nice that the chargers can be monitored via Bluetooth, although this is not a requirement. It has proven to be a great help, for example when the boat is in winter storage and I can check from the comfort of a heated car.

 

[webcraft]

I doubt you’ll find a battery charger with a 13a 240v output.

I have the same charger on boat as Sandy (above) but for the car I bought one of these:

Amazon.co.uk

Swap out croc clips for ring terminals and leave plug somewhere easily accessible perhaps. It does indeed put out 15a, has a LiFePo setting (for future update if needed) and is actually surprisingly good.

So I bought one of these and have it connected to the batteries permanently as you suggest.

Just plugged it in, it did about 5 mins on DFS (desulfation) and is now charging at between 14.4V and 14.7V and around 11 amps. The charge indicator is flashing on the last bar. 14.7V seems rather high, is it OK for bulk or absorption phases of charging, I know it is too high for trickle charging.

It has a permanent readout even when not plugged in, so seems to also act as a voltmeter.

The temperature readout confuses me though. It seems to get steadily hotter when I unplug it from the shorepower, presumably because the fan stops?

Not sure I want the permanent display, might have to get a cover for it, or I guess putting a switch in the live wire would work?

A bit nerve wracking, I prefer the Cetek charger on the other boat which is hidden in a locker.

 

[fredrussell]

So I bought one of these and have it connected to the batteries permanently as you suggest.

Just plugged it in, it did about 5 mins on DFS (desulfation) and is now charging at between 14.4V and 14.7V and around 11 amps. The charge indicator is flashing on the last bar. 14.7V seems rather high, is it OK for bulk or absorption phases of charging, I know it is too high for trickle charging.

Between 14.4 and 14.7v is what a modern alternator charges at - no need for concern. it’ll drop to a lower voltage as battery ‘fills’.