Generator

[Robbo]

 

I do not know what the Pf of the Victron is, but, some chargers have a Pf as 'bad' as 65%, many around 75%, your quoted 85% would be a vey good one. Pf can be improved to 1 by the (expensive) use of electronics but, few battery chargers have that.

Maybe with the cost of Victrons they do ?

 

You are correct - All needs taking into account before choosing the genny.

The Victron combos do have a power factor of 1, but they do have a weak AC switch which i presume does reduce this.

 

Edit, this is in the manual..

 

Derating of the power factor

Some generators have a waveform which makes it difficult to charge with the normal charge mechanism. Through activating the "Weak AC input" function, another mechanism is used which will enable the MultiPlus to charge under practically any condition.

Disadvantage of using this option is that the input power factor, normally equal or close to 1, will be degraded. This function should be used only when the preceding ones are ineffective.

Edited November 12, 2016 by Robbo

[Timx]

Hi again, thanks for all your answers, lol, and as we get more technical, I am lost, but I have gained from the overall discussion and looking at other threads

 

My first misconception[i hope] is that I read on here that running your engine for a few hours will not take the battery to 100pc, so I thought from that , that I needed extra power apart from just moving the boat/running it on idle, although I do usually travel most days, this is my first winter and can envisage days when I don't want to move[so reading between the lines I go it wrong, if I run it enough it will get it to 100pc]

 

So my new conclusion is, I don't need a generator... SO even if I don't move a lot over the winter, I will at least do one 8 hour day idle and under power till time is achieved in one week, I will run my engine for four hours a day, all the rest of the days either moving or on idle or a mixture of both .

Knowing nothing about it from new I am getting a bit going in..the tech stuff will never go in to the point that I can understand the more technical posts above, so I just need the basics

I read this on line recently-battery voltages: 13.5 – 14.4 volts is a battery under charge. Once the charge stops the battery will quickly drop to 12.6 volts which is where it will sit until you start to draw power. You then have from 12.6 down to 11.5 volts as you use the battery, then it needs charging again to avoid damage. That makes sense to me, and I think I have been doing that,just my love of boating has helped my uneducated mind in battery management.

[Alan de Enfield]

 

Knowing nothing about it from new I am getting a bit going in..the tech stuff will never go in to the point that I can understand the more technical posts above, so I just need the basics

I read this on line recently-battery voltages: 13.5 – 14.4 volts is a battery under charge. Once the charge stops the battery will quickly drop to 12.6 volts which is where it will sit until you start to draw power. You then have from 12.6 down to 11.5 volts as you use the battery, then it needs charging again to avoid damage. That makes sense to me, and I think I have been doing that,just my love of boating has helped my uneducated mind in battery management.

 

NO NO NO

 

A fully charged battery is 12.8 volts (not 12.6v)

 

You must not let the battery fall below 12.1 volts. (50% charged)

11.5 volts means the battery is knackered and will need replacing.

 

All figures refer to no-load (nothing switched on and using power) and nothing charging (ie solar, engine or battery charger switched off)

 

Take all readings a minimum of one hour after no discharge / no charge has started.

 

Edited November 12, 2016 by Alan de Enfield

[Timx]

Hi thanks for that, I had read don't let it go under 12.2v which is my regimen,[ when g/f not aboard,who gets up, puts ch and coffee machine on] i copied that off living on a etc,damn. but thank you

[WotEver]

Hi thanks for that, I had read don't let it go under 12.2v which is my regimen,[ when g/f not aboard,who gets up, puts ch and coffee machine on] i copied that off living on a etc,damn. but thank you

The 'rule' about not going below 12.2V for all intents and purposes isn't a flexible one if you want your batteries to last. It isn't a case of "That's what I usually do but..." There is no 'but'.

 

You have swung from "my engine running won't be enough so I need a genny" to "I think my engine running will probably be enough". The trouble with both of these opinions is that they're guesses. You can't guess your way to a long battery life. You MUST have a way of determining when your batteries are fully charged so that when they're not fully charged you continue charging until they are.

 

The simplest way of achieving that will be by fitting an ammeter and monitoring charge current. Total outlay around £15.

 

Tony

[Timx]

Would the reading from the mppt controller help me until I get the ammeter or smart gauge fitted, I am running it till it goes on float, and then for another hour, so about 4 hours ,three hours of which it is in absorption, what figures would I need to be looking at to help guestimate, it will be a time till I can source and get someone to fit a proper meter.

[WotEver]

There's an ammeter with shunt for a fiver here...

http://m.ebay.co.uk/itm/171368601158?rmvSB=true&ul_ref=http%3A%2F%2Frover.ebay.com%2Frover%2F1%2F710-53481-19255-0%2F1%3Ftype%3D4%26campId%3D5336432705%26toolId%3D10001%26customId%3Divjvkc6vt50004m600003%26mpre%3Dhttp%253A%252F%252Fwww.ebay.co.uk%252Fitm%252F0-100V-100A-Shunt-DC-Digital-Voltmeter-Ammeter-LED-Amp-Volt-Meter-12v-24v-car-%252F171368601158%26srcrot%3D710-53481-19255-0%26rvr_id%3D1124174896096&_mwBanner=1&ul_noapp=true

 

You might have to wait a little while for it to arrive and I have no idea of the quality but for a fiver it's worth a punt.

 

I wouldn't think you'd be getting anything like enough out of your solar at this time of year but what you're looking for is a charging current of about 1% of the battery capacity (so 1.1A for a 110Ah battery, 2.2A for 220Ah etc) with a charging voltage above 14.4V. If you can achieve that then you're as near as makes no difference to fully charged.

[Dave Payne]

what you're looking for is a charging current of about 1% of the battery capacity (so 1.1A for a 110Ah battery, 2.2A for 220Ah etc) with a charging voltage above 14.4V. If you can achieve that then you're as near as makes no difference to fully charged.

Thanks, been trying to put all the talk on charging inti sense in my head, so the above if you have an ammeter with shunt, let the batteries charge for a period and watch the ammemeter and voltmeter to get these figures?

[WotEver]

Basically yes.

Here is the same info in more depth:

http://thunderboat.boards.net/thread/817/battery-charging-primer

[Dave Payne]

Oo the other place!

 

What size cable from batteries to shunt, and a fuse is needed also I guess?

 

Was thinking of a permanent fitting.

[WotEver]

All those depend on..,

1. Maximum current of controller.

2. Cable length from controller to batteries.

 

Let us know those two and we can answer.

[Dave Payne]

One in the link, say 8ft ?

[WotEver]

One in the link, say 8ft ?

Oh sorry, you're talking about that shunt ammeter I linked? That's easy

 

You remove everything that's currently connected to the battery negative (EVERY WIRE) and connect them to one end of the shunt. Connect the other end of the shunt with a short bit of cable same thickness as all the rest of the battery wires, which will be at least 25mm.

 

Then 3 lengths of whatever cable the instructions suggest (probably 1mm) to connect up the ammeter to the battery and the shunt. It's a half hour job.

 

There is a wiring diagram on the listing.

 

Yes, the +ve battery connection to the ammeter/voltmeter should be fused at 1A.

Edited November 15, 2016 by WotEver

[Timx]

ha ok

[Tony Brooks]

I have just noticed that you talk about running the engine on idle to charge the batteries. I have not seen that picked up on in the thread so it is NOT the way to do it.

 

You can disconnect the gear mechanism so you can rev the engine in neutral. This may be by pulling the whole lever out of the control body, pushing a button, in or pulling a button out.

 

For now, before you fit that ammeter, charge at around 1500rpm for the first hour, 1000 rpm for the rest of the time. Once you have the ammeter keep adjusting the revs so the ammeter always shows the highest charge it can. You will have to gradually reduce the revs as the batteries take a charge.

 

This will be better fro the engine because for the first period of time the alternator will be loading the engine probably more than cruising along the canal does.

[Dave Payne]

Thought it was frowned upon to do the above?

[Jak]

I don't think there's much of an alternative if you are off the grid. Hopefully putting on some solar in the spring will help, but until then?

[Dave Payne]

Seem to remember a thread a couple of tears ago saying it causes glazing?

 

I might be wrong but it rings a bell

[Timx]

 

I have just noticed that you talk about running the engine on idle to charge the batteries. I have not seen that picked up on in the thread so it is NOT the way to do it.

 

You can disconnect the gear mechanism so you can rev the engine in neutral. This may be by pulling the whole lever out of the control body, pushing a button, in or pulling a button out.

 

For now, before you fit that ammeter, charge at around 1500rpm for the first hour, 1000 rpm for the rest of the time. Once you have the ammeter keep adjusting the revs so the ammeter always shows the highest charge it can. You will have to gradually reduce the revs as the batteries take a charge.

 

This will be better fro the engine because for the first period of time the alternator will be loading the engine probably more than cruising along the canal does.

 

Thank you for that, I will. Have a foot injury and single handed for a few days so cant move much at the moment,

Edited November 16, 2016 by Timx

[MtB]

Seem to remember a thread a couple of tears ago saying it causes glazing?

 

I might be wrong but it rings a bell

 

 

Urban myth. Mainly because it sounds good when spouted in pubs...

 

Even if it is true, the batteries don't care. They still need enough engine revs to charge as Tony describes.

[Tony Brooks]

Thought it was frowned upon to do the above?

 

By who and how qualified/experienced are they? Note I said rev it in neutral and explained how to set the control so it could be revved in neutral.

 

 

Seem to remember a thread a couple of tears ago saying it causes glazing?

 

I might be wrong but it rings a bell

 

 

That is why I said have it revving. At idle the alternator will not have a significant output (or none at all if it did not energise) so will put very little load on the engine. When its revving at maximum alternator output there will be a load, at least at first, that may well be greater than the load when cruising so the load reduces the likelihood of bore glazing.

 

In any case the propensity to glaze bores has a lot more factors than just engine speed and load - including things in the mind of the mariniser than may or may or not be correct.

 

I suspect running for hours on idle is far more likely to glaze bores if the engine design is prone to it.

 

 

 

 

[Timx]

Well gave it 5 hours of above mentioned regime, lowered revs after 3 hours when when it went on to float and kept it going for another two hours. After I turned it off , about half an hour later I checked the volts from the controller display and it said 12.7 v, so great, but after 3 hrs it had dropped to 12.5, I have an inverter 2,5k permanently on, also a fridge and water pump, and I did have my dongle charging for an hour, but that's surely a sign my batts not holding charge.

Last night much the same and when I got up batts were 12.1v that's with the inverter etc on, So I am guessing but the 8 yr old batteries appear knackered and its gonna cost me 8 ton plus someone to fit them[they are agm 220v] .Happy days.

Cant tell if I have helped kill them as apart from the constant pull on them and a bit of telly late at night I don't use power, its moor up by a pub get off and go pub,but possibly/probably, as I wasn't checking,as I do, do long days on the boat. But they aren't gonna last forever I suppose, and I have learnt a lot from the knowledge dispensed on here. So I will be a lot more knowledgeable in future management, not in the chemistry /physics but in the management so thanks, your comments are helping the unknowledgeable.

P.S I am going to a boat yard to get them to check em over, but they will have to be changed eventually ,like now I think, as I want the choice of powr within reason.

Edited November 19, 2016 by Timx

[WotEver]

Well gave it 5 hours of above mentioned regime, lowered revs after 3 hours when when it went on to float and kept it going for another two hours.

What was the charge current at that point?

[Alan de Enfield]

When you change them don't just 'give them away' when the marina offer to dispose of them for you.

 

I have been getting £5 each for 60Ah, £10 for 110Ah and £20 for 230Ah batteries.

 

If you have 5 x 220Ah that's £100 contribution to your new batteries.

[Timx]

What was the charge current at that point?

I never looked at the voltage charge whilst charging[well I did but it was high and did not know the relevance], I just looked that it was on float as above post,so if your asking, that must be a pertinent question that might help me further. I think not sure ,that it was telling me o amps, so I was about to turn it off anyway, so thought that was another sign I was wasting charging further at that point.

When you change them don't just 'give them away' when the marina offer to dispose of them for you.

 

I have been getting £5 each for 60Ah, £10 for 110Ah and £20 for 230Ah batteries.

 

If you have 5 x 220Ah that's £100 contribution to your new batteries.

Thanks, never considered that, I have 3 x 220, I will keep it in mind.