rcx132
Philip
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Samsung or Panasonic cells. Avoid any Chinese cells, they outright lie about capacity.
- Thread starter sg66
- Start date
Going to go for fogstar just working out which size, can't believe I'm spending more on a battery than half the cars I've ever bought it's just the charging of it whilst driving, if the solar charger will charge it from car ......
Misterg
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I don't believe so - the BlueSolar ones need an input voltage at least 5V higher than the battery voltage (section 4.3 below).
Your cigarette lighter won't be able to provide that.
4. Installation
Ring (I think) sold a unit that did both, but they were notoriously unreliable (as of a few years ago).
You could use a good, old-fashioned split charge relay if you had a lead-acid leisure battery though.
(Or a DC-DC charger if you're feeling flush.)
Right thanks for that, I would need to buy the solar charger anyway and I already have a 10amp DC 12v to 12v so I will add another socket for the solar and run them separate.I don't believe so - the BlueSolar ones need an input voltage at least 5V higher than the battery voltage (section 4.3 below).
Your cigarette lighter won't be able to provide that.
4. Installation
www.victronenergy.com
Ring (I think) sold a unit that did both, but they were notoriously unreliable (as of a few years ago).
You could use a good, old-fashioned split charge relay if you had a lead-acid leisure battery though.
(Or a DC-DC charger if you're feeling flush.)
So I have the battery installed and running the fridge, it's safe to say either the fridge is way more efficient than all the examples I googled, or the ones doing the examples were not using actual data, I fear it may be a bit of both.
So my plan was for it to easily last a weekend, a long weekend at a push as it turns out current draw from battery is tiny, so tiny that going off the first 30hrs it's highly likely to last weeks, I Gould have easily halved the size of the battery ohh well
So my plan was for it to easily last a weekend, a long weekend at a push as it turns out current draw from battery is tiny, so tiny that going off the first 30hrs it's highly likely to last weeks, I Gould have easily halved the size of the battery ohh well
Misterg
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Have you got the solar running too?
If not, I fear that something is amiss - 2AH consumption over 30hours is unfeasibly small for a fridge. Even the super-efficient top-loaders will use 15-20AH a day to stay cool. Our CRX50 uses ~30AH a day or ~40AH in hot weather (per Victron BMV 7xx battery monitor).
Nope no solar and fridge is cold, it is a small draw fridge, I paid a bit more for the newer electronic thermostat one which is the most efficient one they do, I'm just going to run the battery down to 30% and see how long it lasts.
I will update and see if battery suddenly drops a huge amount of capacity
I will update and see if battery suddenly drops a huge amount of capacity
Misterg
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How small is small?
FWIW: I would suggest double-checking the wiring around your current shunt to make sure it's actually registering the current drawn by the fridge (i.e. fridge isn't connected directly to the battery, or anything daft like that).
The data comes direct from the battery and its own management.
Small it's 20l, I only wanted something for the weekend, we used to camping with just a small cool box, this is high tec
They recommend 30% which is why I'm leaving fridge on, I can then switch the battery into storage mode but they recommend a charge and discharge every 3 month to get best out of it, it's a smart Bluetooth charger that does proper lithium charge and float and whatever else lithium batteries need, I didn't skimp but it does look like I could have saved a lot on size of battery.
Good job I didn't go for the 280ah cause it's in the same size case and I nearly did.
Why is lead for storage dead? Weight doesn't matter for many storage applications. I have looked into forklift batteries for a ground based solar system. Literally 1/4 the cost for the equivalent lithium ion solution. A 48kw/h forklift battery can be bought new for £3500. With intelligent chargers they have a very long lifespan and are easy to recycle. Safer than lithium ion and far easier to recycle. You also get 1/3 of your money back for the scrap lead!
It was weight and size for me, I looked at a deep cycle AGM lead battery it was £300.00 weighed 60kg and was too long to fit, lithium was smaller and weighs 25kg with better discharge curve, much faster charging if required, Bluetooth and a 10yr warranty.
I kno
I know it was critical in your application - I was responding to the other post's generalisation
julianthegypsy
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A friend of mine had a shoreline under counter size fridge in his bus and it drew about under an amp on 12 volts, kicking to three when the compressor kicked in but dropping back immediately to about 1.5A with it running. Remarkably efficient and easily ran off a couple of 100 watt panels, bearing in mind that this was ten years ago and things have improved even more since then.
Weight pure and simple. Imagine a forklift battery in a car!
Where weight is of no concern lead acid is still king.
I kno
I know it was critical in your application - I was responding to the other post's generalisation
I get it from the safety bit alone, I could have paid at least half probably less than that, I paid the extra for hopefully grade a car quality Lithium cells, I'm going to be sleeping very close to it
Fridge still going, it's got 4 normal settings and then a night time and a freezer option.
I'm going to do 3 days on each setting and workout the power use v temp.
I've put a small bottle of water in so I can measure the temp of the liquid, I've got a very accurate tested temp probe.
It's currently running for 3min every 25mins it's no wonder the battery is lasting as long
I'm going to do 3 days on each setting and workout the power use v temp.
I've put a small bottle of water in so I can measure the temp of the liquid, I've got a very accurate tested temp probe.
It's currently running for 3min every 25mins it's no wonder the battery is lasting as long
barracuda816
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Problem is 48kw is only around 24kw if you want it to last and it still will degrade quicker. Lead acid still has its uses but storage is not its strong suit. Also safety wise it depends on the chemistry. Lithium titanate is very safe and LifePo4 is safe. Also the new generation of solid state lithium are also safe. In general lithium batteries have a longer life, lower self discharge rates (important for back up systems) can accept a higher charge meaning quicker recharge either from solar or a generator if we are talking about home storage.
Price wise there is not a huge difference anymore. I would recommend used Ev battery’s as the most cost effective but there are some downsides. But even new LifePo4 cells you are looking at circa £100 per kw. So 40kw = £4000. And that’s usable (still best to only use between 10% empty to 80% but if you do use the full 100% they don’t degrade anywhere near as fast as lead acid.)
