Lithium leisure battery

[GRW]

I think the proof of the pudding etc... & like all things I'm sure the quality & lifespan of all Lithium batts are not remotely equal.

Personal choice, but the general history, safety and performance of lead-acid for the buy cost (& I'm not atm overly worried about weight) makes LA a low cost, low risk choice.
Again, cheaper-end Lithium unknown-brand stuff has to represent taking more of a punt, than established more pricey stuff.

Personally I'd rather risk £100 and get a dud LA, rather than hundreds more on complex, electronic LIPO batteries & chargers & get a dud (& my time on that self-build group suggested that failing Lithium batts (failing to charge not going up in smoke/flames that is) - is not at all uncommon. There were regular posts from people with issues).

 

[fizzy]

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A 38kw/h battery for £2400. Ok so you only get say 28kw/h capacity usable but it is still about 1/3 to 1/4 the cost. And you get back about £800 when you scrap it

 

[sg66]

I think the proof of the pudding etc... & like all things I'm sure the quality & lifespan of all Lithium batts are not remotely equal.

Personal choice, but the general history, safety and performance of lead-acid for the buy cost (& I'm not atm overly worried about weight) makes LA a low cost, low risk choice.
Again, cheaper-end Lithium unknown-brand stuff has to represent taking more of a punt, than established more pricey stuff.

Personally I'd rather risk £100 and get a dud LA, rather than hundreds more on complex, electronic LIPO batteries & chargers & get a dud (& my time on that self-build group suggested that failing Lithium batts (failing to charge not going up in smoke/flames that is) - is not at all uncommon. There were regular posts from people with issues).

Well fogstar have been going 8 years now so as long as they manage another 10 my warranty should be fine

I think big part of the problem is the price point, lots and lots of cheap lithium batteries made with untraceable cells of any quality cause there is a market for cheap.

A house blew up in Germany triggered by lifepo batteries going bang in a big way, so certainly potential for things going badly wrong.

The battery monitoring system plays a big part in keeping things safe, I watched a few strip down vids on some of the cheap batteries available and on more than one board there was no heat sensor, so although it had the ability to shut down on over temp it didn't have the ability to sense it.

Also some of the packing and connections and adhesives used were dubious to say the least.

 

[Martin Hocking]

I’ve found this thread quite interesting but I’m definitely too stupid to understand properly.

Can someone explain what the amp-hour rating of a battery actually means?

I thought I meant the current that could be sustained for one hour before full discharge or is it the number hours at 1 amp before full discharge? Or neither?

Seemingly an amp hour is different in practice depending on the type of battery too.

I’ve got four of these (below) that I think are in good shape, I fancied mucking about with a bit of solar for my shed but even after looking at the data sheet I’m not even sure how much capacity they have.

Probably not a good place to start for playing with sparks but hey ho..,

 

[sg66]

I’ve found this thread quite interesting but I’m definitely too stupid to understand properly.

Can someone explain what the amp-hour rating of a battery actually means?

I thought I meant the current that could be sustained for one hour before full discharge or is it the number hours at 1 amp before full discharge? Or neither?

Seemingly an amp hour is different in practice depending on the type of battery too.

I’ve got four of these (below) that I think are in good shape, I fancied mucking about with a bit of solar for my shed but even after looking at the data sheet I’m not even sure how much capacity they have.

Probably not a good place to start for playing with sparks but hey ho..,

View attachment 461345

It's just the amount of current v time a 10ah battery would run a 1amp device for 10 hours or a 10 amp device for 1 hour a 20 amp for 30mins etc

 

[sg66]

One of the other advantages of lithium is you can fit it any way you want, on its side, upside down doesn't matter it will burn in any orientation I mean run.....

 

[voipio]

The Amp hour rating of a battery is normally estimated as the cumulative current drawn (i.e. current x time; usually Amps x hours, or milliAmps x hours for smaller batteries), starting from full charge, to a defined end point voltage per cell (e.g. 1.8V for a lead acid cell). The Amp hour rating is affected by the discharge rate. The higher the discharge rate the lower the actual Ah capacity estimate tends to be, for a given battery design. The "standard" discharge rates in Amps tend to be C10, or one tenth the Ah capacity (e.g. a 110Ah battery being discharged at 11A), but some manufacturers will state the C20 capacity, or even C5 capacity, the latter being typically quoted for traction batteries for forklifts. Discharging a 110Ah C10 lead acid battery at 110Amps (i.e. C1 rate) will result in somewhat less than one hour's run time to the end point voltage.

 

[sg66]

So fridge been on a week now 193ah left and I'm up to 3 on the normal settings

It runs for just over 3mins about every 20mins so starting to run a little longer and a small amount of heat build up in the compressor, still barely warm to the touch.

Definitely safe to say I'm ok for a long weekend

 

[sg66]

Time for discharge also needs specifying. A lead/acid battery is usually rated for 20 hours for the discharge. Shorten the time (increase the Amps) and the battery capacity will decrease.



Gel and AGM lead/acid can also be fitted most ways (but not upside down I expect).

It was just a rough idea for someone who didn't understand the concept of the rating, mine one will do a max continuous discharge at 250a but seeing as I have a 30a fuse from the battery it's safe to say I'm not planning on it, handy if you want to flatten it quickly with a 2500w inverter but I'm not..

 

[Martin Hocking]

Thanks @sg66 and @voipio that helps tonnes.

I still can’t say I understand the way the people who make the batteries I have rate theirs, because the rating over time seems to be the opposite of what @not done it yet has said (which made perfect sense).

Still, now I understand a bit clearer I’d take a stab at saying that the batteries I have are around 60ah measured as C1.

 

[Martin Hocking]

Having just posted the above and re-read the helpful replies I still haven’t got it right have I!

I’m sure I used to understand this, the more I look at it, it almost seems like all the different ways the ah capacity is measured seem to make it almost arbitrary.

I do think I’m not incorrect in my saying that the batteries I have can discharge approximately 60amps for 1 hour. But they aren’t what would be called a 60ah battery.

 

[Misterg]

I do think I’m not incorrect in my saying that the batteries I have can discharge approximately 60amps for 1 hour. But they aren’t what would be called a 60ah battery.

You are correct. Most commonly, capacity at the 20 hour rate is quoted making yours 100Ah.

 

[sg66]

Fridge still going as is battery now on highest or lowest setting before coming a freezer, on no 3 the temp is 4.6, all of the temps are very consistent.

 

[sg66]

Still going, been through all the normal settings and now it's onto freezer mode

 

[sg66]

Well freezer mode works.

 

[barracuda816]

Which fridge do you have. Seems very economical. what do you think of the noise. I have a domestic 80cre I had a crx before and it was good but this cre is frankly crap. Quite loud and not particularly well insulated.

 

[GRW]

Looks like that Fridge / Batt combo performs really well

My old Electrolux 3-way ones (I have 2 fully working ones) would of course be rubbish on battery. I have to have a Relay off a switched live so the fridge can only use DC when travelling (in fact I messed-up a bit when I ran a single DC cable feed to the fridge - as of course this means without the van ignition on the Igniter for the gas is isolated - but it's a minor inconvenience).
On gas the fridge is silent & very economical - but I don't think it chills quite as well as your Compressor item.

 

[sg66]

Which fridge do you have. Seems very economical. what do you think of the noise. I have a domestic 80cre I had a crx before and it was good but this cre is frankly crap. Quite loud and not particularly well insulated.

It's a small draw fridge, it's the latest incarnation from vertafrigo, has electronic control over the temp, the older version was cheaper, I believe dometic re brand and sell the same thing.

Noise wise it's not too bad but I haven't slept with it yet so yo speak

The cooling fan is probably louder than the compressor

it has a night time mode which is the last up on the test run, I'm wondering if that runs the fan slower or not at all, will find out next week, I'm pretty certain I'm still going to be above 30% on battery capacity left, will know by about wed next week

 

[sg66]

Looks like that Fridge / Batt combo performs really well

My old Electrolux 3-way ones (I have 2 fully working ones) would of course be rubbish on battery. I have to have a Relay off a switched live so the fridge can only use DC when travelling (in fact I messed-up a bit when I ran a single DC cable feed to the fridge - as of course this means without the van ignition on the Igniter for the gas is isolated - but it's a minor inconvenience).
On gas the fridge is silent & very economical - but I don't think it chills quite as well as your Compressor item.

You have an absorption fridge, they are great on gas and silent, if it ever stops working after standing a long time, take it out turn it upside and leave it for a while.

 

[GRW]

You have an absorption fridge, they are great on gas and silent, if it ever stops working after standing a long time, take it out turn it upside and leave it for a while.

Yep - ancient things but robust & effective (think the ones the van is 1990-ish). I have 2 that I've tinkered with & upgraded from push-button to 12v Piezo ignition (much easier & parts were off non-working fridges picked up for a few quid).
So I have a spare as well (they aren't worth an awful lot to sell, so I might as well hang onto the 2nd one as backup - that said there's not much to go wrong except age and oxidisation).