Batteries and living aboard

[ditchcrawler]

Oh but hang on, I'm using 25Ah at 12v. I have a 24v starter and alternator so have to have my domestic batteries at 24v too. But my power audit was for 12v appliances. I have a 24v to 12v dc step-down box of tricks.

Are you measuring your use in Ah and if so where, or calculating it.

[Dalslandia]

Yes fair enough. The electrons are only lost due to gassing and that occurs mostly near the end of the charge. Overall our Trojans are giving 93 to 94% on the Mastershunt with typical charges from 60-something % SoC

 

Don't forget there's a big difference between charge efficiency (amp hours out and in) vs power efficiency (watt hours out and in). The latter is always a lot worse due to high charge voltage and low discharge voltage.

 

That might be so, total Watt out/in, that*s what was interesting back then.

[matty40s]

P'raps cruise more than just one bridge distance occasionally.....

 

☺

[Dalslandia]

P'raps cruise more than just one bridge distance occasionally.....

 

☺

 

OCC? Occasionally Continual Cruising :-)

Edited January 14, 2016 by Dalslandia

[Chewbacka]

There is another idea and that is to use batteries that are tolerant of abuse, but the initial cost is very high. I am thinking of NiFe batteries.

I don't know why NiFe batteries are so high cost as the Ni is not that expensive compared to Pb.

Never used one myself - cost too much - but the spec looks good and they do tolerate a lot of abuse.

[cuthound]

There is another idea and that is to use batteries that are tolerant of abuse, but the initial cost is very high. I am thinking of NiFe batteries.

I don't know why NiFe batteries are so high cost as the Ni is not that expensive compared to Pb.

Never used one myself - cost too much - but the spec looks good and they do tolerate a lot of abuse.

Economy of scale, orders of magnitude of lead acid batts made compared to nife.

[Pykebird]

God all these numbers look confusing!! All I know is I run my engine in the evening for around 2 hours, get hot water, charge batteries.

Clever dial thing sits at around 12.4 first thing in the morning, lowers a bit whilst I have breakie.

When I return in the evening its around 12.3 .I start the engine again. Deja vu?

4×125 gel batteries, 375 amp solar, 12v fridge and 12v freezer on 24/7.As many electrical gizmos I can fit on board.

[Sea Dog]

There is another idea and that is to use batteries that are tolerant of abuse....

Thing is, if your average input isn't bigger than your average output (because charging isn't 100% efficient) you're on a downward spiral that ends in flat batteries. Some can withstand being flattened better than others, but that doesn't keep the lights on.

[TheBiscuits]

Each day, remove the batteries, place them in the back of your van, wire them in parallel to the vehicle battery. Leave the van ticking over for most of the day...

 

You might wish to continue ignoring me ?

That is silly talk.

 

Carry the two batteries in a large sports bag covered by some plumbing stuff. Sneakily plug in to a convenient socket in customers houses.

 

Have two more batteries on the bote, so when you get back in the dark the lights will work.

[WotEver]

That is silly talk.

 

Carry the two batteries in a large sports bag covered by some plumbing stuff. Sneakily plug in to a convenient socket in customers houses.

 

Have two more batteries on the bote, so when you get back in the dark the lights will work.

Yes, that is far more sensible. I was just being silly.

[Arthur Brown]

Realistically fuel powered generation in the winter is ideal for the bulk stage of charge and solar is ideal for the final stages. Sadly solar output in winter is only 8 - 10% of the summer peak so 12 - 10x the amount of solar is the perfect silent and green answer.

Otherwise cram in as much as you can from the generator in the morning then leave the solar to do what little it can towards the final charge stages.

 

If you are doing a lot of driving then you could carry a battery on charge, then lug it back to the boat at end of day, Possibly use a B2B charger to transfer power from "jump starter" to house battery.

 

If your location permits you could get a little electricity from a Rutland or similar fan in the sky, In the winter any electricity coming in is good! however it's very dependant on the availability of good steady wind in your locality, a friend with an off grid house swears by his Rutland turbine but he's on the see wall of the Wash with constant wind and a 24/7 availability of 5a steady (into 1000ah). Most people inland swear AT wind turbines.

[MtB]

P'raps cruise more than just one bridge distance occasionally.....

 

☺

 

 

Yes very droll but it looks like you haven't actually understood the problem I was seeking to solve...

 

☺

Are you measuring your use in Ah and if so where, or calculating it.

 

 

I'm calculating it based on a series of assumptions, like the proportion of time the fridge compressor is running etc.

 

Estimating would be a better word...

[WotEver]

 

Estimating would be a better word...

You're being unkind to yourself. You've done a power audit ?

[MtB]

There is another idea and that is to use batteries that are tolerant of abuse, but the initial cost is very high. I am thinking of NiFe batteries.

I don't know why NiFe batteries are so high cost as the Ni is not that expensive compared to Pb.

Never used one myself - cost too much - but the spec looks good and they do tolerate a lot of abuse.

 

Interesting! I hadn't heard of them until you posted.

 

Bimble flog 'em http://www.bimblesolar.com/nifebatteries

 

£1k for a 12v 200Ah bank that will last 40 years while you beat the hell out of it. I think that looks pretty attractive!

[WotEver]

Result!

[TheBiscuits]

 

Interesting! I hadn't heard of them until you posted.

 

Bimble flog 'em http://www.bimblesolar.com/nifebatteries

 

£1k for a 12v 200Ah bank that will last 40 years while you beat the hell out of it. I think that looks pretty attractive!

It will still need charging Mike.

 

You might not break it, but it will still be flat!

 

Does a pedal powered battery charger not appeal?

[Arthur Brown]

The issue with Nickel batteries is that they need a different charge regime from the standard Lead Acid chemistry so you would need to get the power from the alternator controlled by a different regulator.

[Richard10002]

 

Interesting! I hadn't heard of them until you posted.

 

Bimble flog 'em http://www.bimblesolar.com/nifebatteries

 

£1k for a 12v 200Ah bank that will last 40 years while you beat the hell out of it. I think that looks pretty attractive!

 

 

We keep being told that things will last 40 years, or lights will last 60,000 hours, or similar... yet these things havent existed long enough for us to know whether it could be true, or mere marketing puffery??

[WotEver]

We keep being told that things will last 40 years, or lights will last 60,000 hours, or similar... yet these things havent existed long enough for us to know whether it could be true, or mere marketing puffery??

Well, if you plough through the pretty poor grammar of that link they claim that some NiFe batteries are still going after 80 years!

 

However... Yes, it sounds like marketing puffery. They have a 'Design Life' of 40 years. No mention of a 40 year guarantee though

[peterboat]

Well, if you plough through the pretty poor grammar of that link they claim that some NiFe batteries are still going after 80 years!

 

However... Yes, it sounds like marketing puffery. They have a 'Design Life' of 40 years. No mention of a 40 year guarantee though

exactly one of my full traction banks is 10 years old and still good cos i had them checked. my soar is doing nothing much at this time of year so my wispergen is doing its stuff

[Chewbacka]

exactly one of my full traction banks is 10 years old and still good cos i had them checked. my soar is doing nothing much at this time of year so my wispergen is doing its stuff

That's good to hear, but you are in the fortunate position of being able to take good care of your batteries whereas Mike's work commitments don't allow adequate charging during the week.

It is possible a bigger bank of batteries which would take longer to over discharge and so last the working week and then be recharged at the weekend would help his battery life, but the downside is he would be spending a lot of his weekend battery charging............

[WotEver]

Yeah, Mike's problem (in the winter) is that he can't really use any worthwhile amounts of leccy at all.

 

Forget charging regimes (he doesn't (can't) have one), forget bank size.

 

Forget any kind of monitoring too - he already knows the answer.

[alan_fincher]

 

 

We keep being told that things will last 40 years, or lights will last 60,000 hours, or similar... yet these things havent existed long enough for us to know whether it could be true, or mere marketing puffery??

 

Errm.....

 

Invented over 100 years ago by Thomas Edison as a non-polluting and non-consumable alternative to Lead Acid

 

 

We made extensive use of NiFe cells in the labs when I was at school some 50 years ago, so hardly!

 

Mind you, they were fairly knackered!

[nicknorman]

That's good to hear, but you are in the fortunate position of being able to take good care of your batteries whereas Mike's work commitments don't allow adequate charging during the week.

It is possible a bigger bank of batteries which would take longer to over discharge and so last the working week and then be recharged at the weekend would help his battery life, but the downside is he would be spending a lot of his weekend battery charging............

However I think it would be reasonable to say that any sized battery bank (of the same technology) takes the same amount of time to recharge, PROVIDED the charging equipment is optimal. This is because the time it takes for the charge to propagate throughout the plates is reasonably constant.p and independent of bank capacity.

 

Therefore with a small bank and charger, one has to charge every day, and then say do a long charge once a week to ward off sulphation. With a much bigger bank, the weekend charge takes the same amount of time but there is no need for daily charging - as I said, provided the charging equipment is scaled up accordingly.

[WotEver]

However I think it would be reasonable to say that any sized battery bank (of the same technology) takes the same amount of time to recharge, PROVIDED the charging equipment is optimal. This is because the time it takes for the charge to propagate throughout the plates is reasonably constant.p and independent of bank capacity.

 

Therefore with a small bank and charger, one has to charge every day, and then say do a long charge once a week to ward off sulphation. With a much bigger bank, the weekend charge takes the same amount of time but there is no need for daily charging - as I said, provided the charging equipment is scaled up accordingly.

Good points, well made. ?