Hi Terry,
Great to read about the new batteries and all your and others inputs, I am looking forward to following these posts but at the moment have a set of 4 x 100A/H AGM's (3yrs old) and am hopeing by keeping A/H draw down to no lower than 50% on occasions that I might get at least another 3 years out of them. I certainly can't wait to alleviate some weight from the van with more power stamina available.
Cheers Kev.
Lithium facts in practice
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Re: Lithium facts in practice
Over six months have gone by since I was here and I thought you may like an update on my Lithium Battery.
We have had a lot of use with the van since January - around 45 nights and about half off grid. The battery has performed perfectly, but because of our brilliant summer and associated long hours of solar absorbing sunshine we have not dropped the battery below 130 amp/hrs despite prodigious use of Nespresso coffee machine, pop up toaster and hair drier, as well as the normal other demands including TV, lighting, water pump, radio, laptop, range hood, washing machine, camera and cell phone charging etc.
Although (on T1 Terry's recommendation) I have purchased a "cell logger" I still have not got around to installing it.
However, on the plus side, regular manual checking backs up my suppliers claim as all four cells have remained at virtually identical voltage since new. To be fair though, the battery has yet to be discharged to any great depth which may have more effect on cell balance than the relatively light use it is currently getting.
We are heading away tomorrow for 7 - 8 nights (all off grid) and being mid winter there will be less solar and far greater demand, giving the technology a bit more of a workout. I have been wondering if I could have saved some bucks and run with a 100 Amp/hr battery
Cheers Chris
We have had a lot of use with the van since January - around 45 nights and about half off grid. The battery has performed perfectly, but because of our brilliant summer and associated long hours of solar absorbing sunshine we have not dropped the battery below 130 amp/hrs despite prodigious use of Nespresso coffee machine, pop up toaster and hair drier, as well as the normal other demands including TV, lighting, water pump, radio, laptop, range hood, washing machine, camera and cell phone charging etc.
Although (on T1 Terry's recommendation) I have purchased a "cell logger" I still have not got around to installing it.


We are heading away tomorrow for 7 - 8 nights (all off grid) and being mid winter there will be less solar and far greater demand, giving the technology a bit more of a workout. I have been wondering if I could have saved some bucks and run with a 100 Amp/hr battery

Cheers Chris
NZMCA # 15589
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Re: Lithium facts in practice
Hi Chris, I think the winter trip will confirm the wisdom of getting a higher capacity battery pack, you still want the coffee machine and toaster to work first thing in the morning and can you imagine SWMBO then having to wait till lunch time for enough recharge in the batteries to use the hair drier 

A person may fail many times, they only become a failure when they blame someone else John Burrows
Those who struggle to become a leader, rarely know a clear direction forward for anyone but themselves
Those who struggle to become a leader, rarely know a clear direction forward for anyone but themselves
Re: Lithium facts in practice
Hi Terry & others,
Can you tell me what would be the size & current cost for a Lithium battery pack suitable for running an 80 litre fridge & a few LED's for 72 hours with no solar, alternator or gennie input? i.e.. Charge it at home using a mains charger before leaving for the weekend & then recharge it once back home again?
If charging like this, using whatever charger the owner already has, what process/precautions need to be adopted?
Used this way could be a potentially large 4wd weekend camper market.
Cuppa
Can you tell me what would be the size & current cost for a Lithium battery pack suitable for running an 80 litre fridge & a few LED's for 72 hours with no solar, alternator or gennie input? i.e.. Charge it at home using a mains charger before leaving for the weekend & then recharge it once back home again?
If charging like this, using whatever charger the owner already has, what process/precautions need to be adopted?
Used this way could be a potentially large 4wd weekend camper market.
Cuppa
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Re: Lithium facts in practice
Cuppa,
Based on the very basic info,, assuming 6a draw on the fridge for 50% running time over the 72hrs then 200 ah should do it. Halve that with a 100w solar panel. Roughly 1200 for the battery.
Terry would give more accurate figures
Based on the very basic info,, assuming 6a draw on the fridge for 50% running time over the 72hrs then 200 ah should do it. Halve that with a 100w solar panel. Roughly 1200 for the battery.
Terry would give more accurate figures
Wobblybox on wheels
Pace Arrow. La de da, property in two continents..
Pace Arrow. La de da, property in two continents..
Re: Lithium facts in practice
Thanks Martin,
I think 50% 6a draw would be about right.
So how much would a 200ah Lithium battery pack cost?
And what if any precautions should be taken, if different to LA batteries, when recharging with a mains charger?
Also how much would a 200ah battery weigh, approx & what size would it be, approx?
Cuppa
I think 50% 6a draw would be about right.
So how much would a 200ah Lithium battery pack cost?
And what if any precautions should be taken, if different to LA batteries, when recharging with a mains charger?
Also how much would a 200ah battery weigh, approx & what size would it be, approx?
Cuppa
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Re: Lithium facts in practice
More realistic is 2 A average for the fridge in non-tropical conditions and 0.5 A average for the LEDs so total of 180 Ah over 72 h. Say 200 Ah. So perhaps a 250 Ah Li battery?dapope wrote:assuming 6a draw on the fridge for 50% running time over the 72hrs...
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Re: Lithium facts in practice
While away for a mth over Easter the alternator died in the Mazda, a 360Ah Li battery ran everything including the engine electrics, lights and electric blankets for 3 days at a time, recharged from a switch mode charger, an alarm on the cell logger to warn if a cell hit high voltage or low voltage to turn stuff off. After I returned home I discovered why it was always one cell group that was the one hitting both the low and the high each time, I'd failed to tighten a terminal bolt on one of the cells in my rush to hit the road, so it was actually only 270Ah on that cell group. The Waeco fridge and Waeco 60ltr esky set as a freezer ran the whole time we were away to add to the load.Cuppa wrote:Hi Terry & others,
Can you tell me what would be the size & current cost for a Lithium battery pack suitable for running an 80 litre fridge & a few LED's for 72 hours with no solar, alternator or gennie input? i.e.. Charge it at home using a mains charger before leaving for the weekend & then recharge it once back home again?
If charging like this, using whatever charger the owner already has, what process/precautions need to be adopted?
Used this way could be a potentially large 4wd weekend camper market.
Cuppa
For the loads you are giving as an example a 200Ah Li battery could handle, even if it was discharged to 100% of it's capacity, the quoted life is 1,000 cycles, that's 1,000 three day week ends, you would get even longer if you didn't reach the fully discharged level every time. I doubt the user would still have the same rig or the same needs after that period of time, even a full timer with that use pattern that represents 3,000 days, that's over 8 yrs, I'm thinking they probably would have bought a solar panel or two within that period so the 8 yrs becomes extended by...... cost of the basic logger, wiring and alarm, $28 plus freight for the logger, although the $14 unit would also do the basic job, about $10 for a smoke alarm for Bunnings, maybe $10 in wiring and fuses etc. Before the A$ started to collapse, roughly 1200 for the battery including strapping, plus freight, depends how many cells you build it from as to how many links required, 3 for a 4 x 200Ah cell battery, 11 for an 8 x 100Ah cell battery, the links are $5 ea, not quite the huge $$ expense some try to make out and not near the cost of a commercial unit.
If you consider that gives you the useable capacity of 400Ah of AGM batteries if you use 12v under load as the point where the battery can no longer offer any more useful current, there isn't much difference in price between the two either. The weight, ea 3.2v 100Ah cell weighs 3.5kg, ea 3.2v 200Ah cell weighs 7.3kg, add a bit for weight and strapping, around 30kg for an 8 cell battery and a little bi lighter for the 4 cell battery, compared to 30 plus kg per 100Ah for fullriver agms, useable capacity to weigh they are a country mile ahead.
A person may fail many times, they only become a failure when they blame someone else John Burrows
Those who struggle to become a leader, rarely know a clear direction forward for anyone but themselves
Those who struggle to become a leader, rarely know a clear direction forward for anyone but themselves
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Re: Lithium facts in practice
Cuppa,
Price and dimensions on the link
http://www.evworks.com.au/index.php?pro ... -LFP200AHA
I see they have a charger being sold as suitable for lithium
I know there are other suppliers, but I don't have the links
Peter, the LED draws are minimal, I personally think 70 ah spare is overkill, unless you are running other stuff
A solar panel in the mix though will make a huge difference
I got a 130 semi flexible panel that weighs 4kg for $309, puts out nearly 8a.
Considering buying more, the potential for a 3 or 4 panel foldout system that can sit on the awning is now there!
My 240w folding is a PITA to lug around
I see Terry has thrown his pearls while I was pecking away:)
Price and dimensions on the link

http://www.evworks.com.au/index.php?pro ... -LFP200AHA
I see they have a charger being sold as suitable for lithium
I know there are other suppliers, but I don't have the links
Peter, the LED draws are minimal, I personally think 70 ah spare is overkill, unless you are running other stuff

A solar panel in the mix though will make a huge difference
I got a 130 semi flexible panel that weighs 4kg for $309, puts out nearly 8a.
Considering buying more, the potential for a 3 or 4 panel foldout system that can sit on the awning is now there!
My 240w folding is a PITA to lug around
I see Terry has thrown his pearls while I was pecking away:)
Wobblybox on wheels
Pace Arrow. La de da, property in two continents..
Pace Arrow. La de da, property in two continents..
Re: Lithium facts in practice
Ok, the reason I'm asking is because I'm discussing batteries on a 4wd forum I'm on. The population of such forums often make unealistic claims of running large fridges for long periods of time on small batteries, with no additional charging sources. Many buy fridges looking only at capacity without thinking about the power required to run them. In short much of the thinking about such matters is far less sophisticated than on most RV forums.
The current opportunity to educate that has arisen involves a chap complaining that his 100ah AGM has died (will no longer accept any charge) & is asking for advice on a better brand 100ah battery which will run his 80 litre fridge for 3 days. ( it is not uncommon for batteries to be used without in vehicle charging for weekend use). Naturally I have suggested that no 100ah LA battery will last if used like this, & that if he wants to continue to use batteries like this he would be better off buying the cheapest he can find, rather than looking to buy a 'better' one.
Space & weight are at a premium in a 4wd, so it would seem that Lithium may be particularly suited to this type of use. (Run'em 'til they're 'flat'.)
Waeco state an average current draw of 2.9a for their 80 litre fridge freezer @ 32deg.C ambient. I reckon this might be a tad optimistic, but allowing for the possibility of cooler ambient temps & turning the thermostat up a bit at night time is probably a reasonable figure to work with. If the time driving home on the third day when refrigeration is no longer needed is taken into account then it would seem that a lithium pack of 200 to 250ah capacity might be about right.
I see Terry has posted whilst I've been typing. Thanks. If anyone from the 4wd forum shows interest how would you feel about me directing them to you because as soon as you start talking about cell loggers you are into stuff of which I have no experience & only minimal understanding. Not sure if there will be interest, but if so how best could I put them in touch with you if you are willing? Bear in mind we are likely talking about folk who have little to no electrical understanding & would want a very simple description. Like me they would probably be frightened off by the use of 'foreign sounding' words like 'cell logger', compared to 'doodad which cuts off charge if any of the battery cell voltages reach a pre-set maximum'.
Cuppa
Ps. Thanks for the link Martin.
The current opportunity to educate that has arisen involves a chap complaining that his 100ah AGM has died (will no longer accept any charge) & is asking for advice on a better brand 100ah battery which will run his 80 litre fridge for 3 days. ( it is not uncommon for batteries to be used without in vehicle charging for weekend use). Naturally I have suggested that no 100ah LA battery will last if used like this, & that if he wants to continue to use batteries like this he would be better off buying the cheapest he can find, rather than looking to buy a 'better' one.
Space & weight are at a premium in a 4wd, so it would seem that Lithium may be particularly suited to this type of use. (Run'em 'til they're 'flat'.)
Waeco state an average current draw of 2.9a for their 80 litre fridge freezer @ 32deg.C ambient. I reckon this might be a tad optimistic, but allowing for the possibility of cooler ambient temps & turning the thermostat up a bit at night time is probably a reasonable figure to work with. If the time driving home on the third day when refrigeration is no longer needed is taken into account then it would seem that a lithium pack of 200 to 250ah capacity might be about right.
I see Terry has posted whilst I've been typing. Thanks. If anyone from the 4wd forum shows interest how would you feel about me directing them to you because as soon as you start talking about cell loggers you are into stuff of which I have no experience & only minimal understanding. Not sure if there will be interest, but if so how best could I put them in touch with you if you are willing? Bear in mind we are likely talking about folk who have little to no electrical understanding & would want a very simple description. Like me they would probably be frightened off by the use of 'foreign sounding' words like 'cell logger', compared to 'doodad which cuts off charge if any of the battery cell voltages reach a pre-set maximum'.
Cuppa
Ps. Thanks for the link Martin.