Generator

[Timx]

Hi, Could anyone recommend a generator for the boat to top up the batteries once a week, I have been going into a marina for a day every couple of weeks on my travels to top them up, but finding it harder recently due to wintermoorers taking up free spaces, so thought I would invest in a good reliable gennie.

I have 3x 220 ah batts and a 2500 inverter if that's relevant. I do usually travel about 4 plus hours a day but understand I still need to top the batteries up. Thanks

[system 4-50]

Not commenting on your charging regieme but if you want a generator see the For Sale section on this forum (I am one of those with a gennie for sale...)

[Sea Dog]

I have 3x 220 ah batts and a 2500 inverter if that's relevant. I do usually travel about 4 plus hours a day but understand I still need to top the batteries up. Thanks

A good generator is an expensive item. Before you commit serious funds to it, you need to assess your requirement. If you're travelling 4 hours a day, have a decent alternator and are not a heavy user of electricity, you may well not need to do much more charging, perhaps not any. It may be that a solar panel or two could meet any shortfall in your charging far cheaper than a generator, or it may be that running the engine for a little longer occasionally might be enough to top you up.

 

The first thing you need to do is a 'power audit' to check your needs. Do a search for that term - it's been discussed a lot. Economies in electricity use can be made which change nothing in your comfort but use less power, like turning the inverter off when you don't need 240V, changing to LED lighting, etc.

 

You could also fit a device to monitor your battery State of Charge (SOC) for you. Smartgauge works off battery voltage and is the one if you don't really understand battery charging and the relationship between Amp Hours in and out, charging current and battery voltage levels as it will give you a pretty reasonable percentage figure. If you do understand that stuff, and that the SOC gets progressively less accurate with time on current measuring devices, the NASA or Victron battery monitors will give you a lot more information to interpret yourself (but sooner or later will lie about SOC).

 

Once you've done the above, you'll be able to understand whether you have a charging shortfall and, if you do, how much extra capacity you need to overcome it. Maybe you'll need a generator, maybe solar with a bit of extra engine in the winter, maybe even nothing at all except to be sure your batteries are at full capacity regularly (and not being discharged below about 60% if you want them to last) which your battery monitor will provide.

 

I hope that helps.

[Timx]

Hi thanks for that, I base my electric usage on the victron, if it says less than 12 then I either don't use any electrics or turn engine on, when it goes too low,[only happened once] it turns the electrics off for me.

I was told by previous owner the batts enjoy being fully charged a couple of times a month and he had a gennie he was using , but I didn't buy it off him, because it took up space and involved petrol, and I thought I would just go in a marina overnight occasionally to top them up.

He was a CC so had changed to LEDS and has two solar panels.But even so I thought they had to be charged fully and that only comes with hook up or generator. Thanks again if anyone can point me in the right direction..

[Richard10002]

Honda 20Eui about £1500 new.

 

Very expensive but relatively quiet and will last a long long time.

 

I bought mine second hand, and a bit bashed about, for £750, in Nov 2011. Use it loads, and it hasn't missed a beat, (not serious beats anyway).

[AndyV]

The Honda inverter generators are brilliant bits of kit but, instead of an EU20i I would make a daft sounding suggestion and then explain.

 

The suggestion is to buy 2 EU10i's

 

Second hand 10s are more readily available and you would comfortably buy two for less than the price of one 20. They have a facility that two can be linked so you have the same capacity and if one fails for whatever reason you still have one working. Each will be lighter to carry than a 20 and I would think it would be easier to find storage on a boat for two smaller ones than the bigger one. I think perhaps they might use a bit more fuel though.

[Sea Dog]

Hi thanks for that, I base my electric usage on the victron, if it says less than 12 then I either don't use any electrics or turn engine on, when it goes too low,[only happened once] it turns the electrics off for me.

I was told by previous owner the batts enjoy being fully charged a couple of times a month and he had a gennie he was using , but I didn't buy it off him, because it took up space and involved petrol, and I thought I would just go in a marina overnight occasionally to top them up.

He was a CC so had changed to LEDS and has two solar panels.But even so I thought they had to be charged fully and that only comes with hook up or generator. Thanks again if anyone can point me in the right direction..

12 volts is about 40% charged, so 60% discharged - this will kill your batteries quite quickly. As I said earlier, to avoid damaging your batteries and shortening their life, you need to stay above 60% as much as possible. That 12V (or 11.9 @ 40% more accurately maybe) should be a resting voltage though, so if your batteries are under load when you read the voltage the figure will be misleading.

 

It's not really a case of the batteries enjoying anything. They charge to 80% pretty quickly, then take ages to get slowly closer to 100%. With big batteries like yours, that 80% to 100% is 132 amp hours discharge when new and it'll take a fair bit more than that due to charge efficiency to get them back to 100%. If they don't get to that full charge, they deteriorate more quickly. Never below 60% and returning to 100% as often as possible will keep your capacity higher for longer and get you greatest life from your batteries. As they deteriorate, you'll find they charge faster - this is not a good thing, as they'll also discharge faster as their capacity decreases. You can charge them to 100% as often as you like then and they won't recover (notwithstanding the possible effects of an equalisation charge).

 

Re-read my earlier post. Do a search and read previously posted advice by others on the same subject: it's a regular, I'm surprised you didn't get a curt answer to 'do a search!' it's so regular, but perhaps most of the folks who know this stuff well are no longer posting. If my answer doesn't do it for you, or at least get you thinking beyond simply buying and running a generator without understanding whether it's the right answer, do have a look at the dangers of petrol in narrowboats. Again, a search on this forum might help.

[Timx]

Thanks for answers .and thanks sea dog,thanks for taking the time to post, I have looked at previous threads ,and as yours, I don't really understand, but I do get the general idea. Not sure of the way forward now, no way I could do a power audit or how to make that a difference given that info,.

The batts are 7 yrs old and I have had them 9 months although three months they were on were on hook up, thought generator may help there life, but if not at least a generator will help me in the rainy cold days not to have to use the engine.Thanks again.

[MtB]

Thanks for answers .and thanks sea dog,thanks for taking the time to post, I have looked at previous threads ,and as yours, I don't really understand, but I do get the general idea. Not sure of the way forward now, no way I could do a power audit or how to make that a difference given that info,.

The batts are 7 yrs old and I have had them 9 months although three months they were on were on hook up, thought generator may help there life, but if not at least a generator will help me in the rainy cold days not to have to use the engine.Thanks again.

 

Getting to know batteries and how they behave properly has been a long term project for me, and has been by far the most difficult subject to gain a clear understanding of for me.

 

My advice is not to make wild guesses about what your batteries need, do it from a position of enlightenment. And the first (critically important) step in getting to properly understand your batteries is to know their state of charge at all times. To do this, there is only one product on the market that tells you approachingly accurately - a SmartGauge. So first thing to spend money on is a SmartGauge. Then you'll be able to see what is going on with your batteries, the questions will flow and your knowledge will increase. Then you'll find you have a clearer idea of whether you need a genny or not, or really badly!

 

Once you have your SmartGauge suddenly all the 'battery' threads on here will spring to life and make fascinating reading!

 

Edit to add:

 

A genny alone won't charge your batteries to 100%. You'll need a clever charger too, costing several hundreds of quids. A Sterling "Pro Charge Ultra" is the only one to get for full control of your battery charging.

Edited November 4, 2016 by Mike the Boilerman

[Timx]

Ha fantastic, any link to smartguage recommendations, have had a look, but which one ??

[MtB]

Ha fantastic, any link to smartguage recommendations, have had a look, but which one ??

 

 

There IS only one SmartGauge. Its a brand name. Designed and developed by Gibbo, late of this parish.

 

Cheapest place to get one is Cactus Navigation. Have a google.

Edited November 4, 2016 by Mike the Boilerman

[Tony Brooks]

The current (Amps) of the so called battery charging outlet on many generators, including the Hondas, is only a few Amps and is also unregulated so its an emergency use only thing. As you say you go into marinas to charge your batteries I assume that you have a multi-stage battery charger. You need to ensure that it current rating is low enough of the generator. If it is not the generator will just trip out. Remember that the usable wattage of a 1kVA generator (like the EU10i will only be around 750 watts.

 

If your battery charger is part of the inverter you may be able to set it to a lower output so the generator can run it.

[Geo]

I suspect it might help if you tell us

 

What battery charger you have?

 

Ho often does the Victron tell you it is time to recharge?

 

Other than while cruising how often do you recharge the batteries?

[Exturnaroundman]

If the batteries are 7 years old, this may answer your question ? Rather than spend money on a generator, new batteries might solve your problems.

[Richard10002]

If the batteries are 7 years old, this may answer your question ? Rather than spend money on a generator, new batteries might solve your problems.

I don't think he suggested he had a problem as such, merely that he wanted to charge sufficiently so that he doesn't get one?

[Exturnaroundman]

7 year old batteries will be well past their best. The op has had them for 9 months only, so probably doesn't know how well they have been looked after. New ones, start from scratch. Sorry only lived aboard for 12 years, no generator, no plug in, solar panels yes, led lights yes, would only have to run the engine for 2 hours a day in winter. Battery life 4-5 years.

[mrsmelly]

7 year old batteries will be well past their best. The op has had them for 9 months only, so probably doesn't know how well they have been looked after. New ones, start from scratch. Sorry only lived aboard for 12 years, no generator, no plug in, solar panels yes, led lights yes, would only have to run the engine for 2 hours a day in winter. Battery life 4-5 years.

 

As a liveaboard of a lot more than 12 years I completely agree with this post. You are spot on. Mine fully charge every day in around 2 hours. I always buy dead cheap and get 2/3 winters out of them then bin em and start again. Sealed jobbies, no topping up nonsense. The key point is never to take them below 12.2.

 

Tim

[Alan de Enfield]

7 year old batteries will be well past their best. The op has had them for 9 months only, so probably doesn't know how well they have been looked after. New ones, start from scratch. Sorry only lived aboard for 12 years, no generator, no plug in, solar panels yes, led lights yes, would only have to run the engine for 2 hours a day in winter. Battery life 4-5 years.

 

Maybe if you are 'only' getting 4-5 years life out of your batteries, and the OP (and the previous owner) have achieved 7 years they have probably looked after them better than you have.

[MtB]

7 year old batteries will be well past their best. The op has had them for 9 months only, so probably doesn't know how well they have been looked after. New ones, start from scratch. Sorry only lived aboard for 12 years, no generator, no plug in, solar panels yes, led lights yes, would only have to run the engine for 2 hours a day in winter. Battery life 4-5 years.

 

 

Really? Now I'm intrigued. Stand by for a stream of questions!

 

Do you run a 12v fridge? How often do you get your batteries charged to 100%? How do you know? A SmartGauge or some other method? Are these Trojans or cheapo leisures you make last for five years?

 

I'd have expected running the engine for two hours a day in winter would not be enough with a fridge, or more than necessary with no fridge, given that an ordinary alternator does not charge quickly in the final stages of charging. Is it modified in any way? Do you carry out a weekly longer charge to get them up to 100%? Do you run an equalisation charge periodically? How do you do that in winter with no genny?

 

I'm intrigued as I am in the process of redesigning my own liveaboard CCer domestic battery and charging system. Thanks for any enlightenment you can offer.

 

 

(Edit to add more questions )

Edited November 5, 2016 by Mike the Boilerman

[Exturnaroundman]

Never had a 12v fridge, had a 240v one which was used summer only, and the solars fed that easily. In winter store food in sealed boxes in the bow/cratch. As another poster said, buy the cheapest batteries and accept they have a certain life span, don't get too het up about equalisation charge and the like, just learn what works best for you.

 

Expect to be shot down in flames ! No wonder we gave it up !

[Geo]

7 year old batteries will be well past their best. The op has had them for 9 months only, so probably doesn't know how well they have been looked after. New ones, start from scratch. Sorry only lived aboard for 12 years, no generator, no plug in, solar panels yes, led lights yes, would only have to run the engine for 2 hours a day in winter. Battery life 4-5 years.

Unless they are deep cycle/traction batteries then that life plus is possible.

[Timx]

Hi thanks for answers

 

 

There IS only one SmartGauge. Its a brand name. Designed and developed by Gibbo, late of this parish.

 

Cheapest place to get one is Cactus Navigation. Have a google.

Thanks I will, just when I looked on amazon, they were different prices, will look again sober.

 

I suspect it might help if you tell us

 

What battery charger you have?

 

Ho often does the Victron tell you it is time to recharge?

 

Other than while cruising how often do you recharge the batteries?

 

The charger is built into the victron, and once it has told me my batteries are low. I have been out cruisng two months 250 hrs previous three months it was on hook up and about two hundred cruising before that when I bought it. Ihave been running the engine every day normally cruising 2 to 6hrs daily, or at least 4hrs a day the engine running.I have only put it on 24hr hook up twice in last two months.

I don't think he suggested he had a problem as such, merely that he wanted to charge sufficiently so that he doesn't get one?

Hi, yeah I thought it was better to charge the batteries fully a couple of times a month as that is what previous owner did, hence my question.Also now is my first winter out cruising and as the weather will presumably get worse than the fantastic weather of late, I will not be able to cruise as much and thought running a generator may be better than running an engine four hours every day on idle. So forgive my ignorance I am trying to learn , i have never picked up a spanner in my life before.I am still surprisedi was able to service the boat myself recently, with a little bit of advice off here and u tube, Battery management seems a bigger question by far. I have a fridge running all the time and water pump, and use TV and laptop at night time.Now the nights are longer is another reason for my question, thanks for all replies.but my knowledge on the technical language on the subject electrics and batteries remains a mystery

[MtB]

Never had a 12v fridge, had a 240v one which was used summer only, and the solars fed that easily. In winter store food in sealed boxes in the bow/cratch. As another poster said, buy the cheapest batteries and accept they have a certain life span, don't get too het up about equalisation charge and the like, just learn what works best for you.

 

Expect to be shot down in flames ! No wonder we gave it up !

 

Thanks for your reply. No fridge in winter make it all make sense.

 

I bet the boats moored near you love you running your engine two hours a day! Or do you mean you cruise for two hours a day?

[blackrose]

 

The charger is built into the victron...

 

But what is the charger output and can it be adjusted down? You've told us you have a Victron 2500 inverter (combi), but the other half of the spec is missing - the charger output. As Tony said earlier, 2500 watts is the max inverter output but before you can spec a generator you will need to know if it can run the charger.

 

So for example your combi will be 2500/100 or 2500/70, etc, with 100 amp or 70 amp being the maximum DC output of the charger.

 

The basic calculation to determine the generator you need to run a 100 amp charger is; 100 x 14.8v (assuming max voltage for charging 12v wet lead acid batteries) x 1.15 power factor to cover efficiency losses = 1,702w or 1.7kW. So had you bought a Honda EU20i (as recommended by some contributors) which has a maximum rated output of 1.6kW and you can't turn down the output of the charger then you will have wasted your money! So find the charger output and do the calculation.

 

The other things to think about and be aware of before you purchase a petrol generator are: Storage - where are you going to store it and store the fuel? Petrol vapours are heavier than air and will settle into bilges. The safety aspects of petrol on boats are similar to LPG. Carbon monoxide - if you run a petrol on or close to a boat you really have to think about which way the wind is blowing and whether carbon monoxide from the exhaust can enter yours or neighbouring boats. The number of boats I've seen with a portable generator running half in/out of the stern doors tells me that a lot of people don't even consider this. Earthing - electrical earthing is an issue that I won't bother going into here, but there are other recent threads on the subject.

Edited November 12, 2016 by blackrose

[Alan de Enfield]

 

 

 

The basic calculation to determine the generator you need to run a 100 amp charger is; 100 x 14.8v (assuming max voltage for charging 12v wet lead acid batteries) x 1.15 power factor to cover efficiency losses = 1,702w or 1.7kW. So had you bought a Honda EU20i (as recommended by some contributors) which has a maximum rated output of 1.6kW and you can't turn down the output of the charger then you will have wasted your money! So find the charger output and do the calculation.

 

 

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.

Edited November 12, 2016 by Alan de Enfield