xsilvergs
Forum Member
Ah, 100 Amp max but 50 Amp recommend. Thanks for clarifying.
AC Fridge In Campervan -.Power Consumption Test
- Thread starter wildebus
- Start date
Squiffy
Forum Member
If you demand more from an alternator than it is designed to make, one of two things will happen 1) The battery will get more and more discharged to the point that 2) The alternator will burn out attempting to supply the necessary ampage to keep the battery at nominal charge and at the same time supply the amount of current required by the various bits of ancillary equipment that may have been added after market. Manufacturers supply most vehicles with alternator that have a small extra capacity when running all electrical items as supplied by the manufacturer of the vehicle, if you wish to use a larger amount of ampage then you will have to fit a larger capacity alternator, this may not be possible for some vehicles as the fitting characteristics are different on each vehicle, though with a bit of engineering knowledge it could be got around, but of course you are then into RPM of the alternator pully as being driven by the crankshaft. Phil
SquirrellCook
Forum Member
Another thing you may notice if you try to take more than the alternator wants to give you, is the squeals of objection from the drive belt.
xsilvergs
Forum Member
The Americans can get a second alternator for their "Promaster"
https://www.thefitrv.com/rv-tips/ou...ithium-battery-solar-alternator-and-inverter/
I won't need any of this as my mind is NOW made up, 60 Amp B2B and a RB100-D
https://www.thefitrv.com/rv-tips/ou...ithium-battery-solar-alternator-and-inverter/
I won't need any of this as my mind is NOW made up, 60 Amp B2B and a RB100-D
wildebus
Forum Member
So if someone stole my batteries out the van (think they may have a hernia now if they did!) what would I do?
Would I buy the Northstar NSB 210FT Blue+ batteries again? or would I get Relion RB100 Lithiums?
The For and Against for both for MY specific requirements...
Costs
Got 3 x NSB 210FT Blue+ Batteries. They provide a total of 645Ah (@C20) - That is a usable 322Ah at 50% DoD (they can go safely lower if need be, but we will stay with 50%
If I got 3 x RB100, I will get 300Ah usable if I take them down to 100% DOD, but that will significantly hurt the life, so let's get 4 x RB100 Units - 360Ah usable at 80% DoD, but with flexibility to go lower it need be.
At 50% DoD, the NSB 210FTs have a Discharge/Charge Cycle of 2050
At 80% DoD, the RB100s have a Discharge/Charge Cycle of 7000 until they drop to 70% capacity (so let's just say 7000)
RB100 costs £900 each, so Bank of 4 will be £3,600; Cost per USABLE Amp (at 80% DOD) is £11.25/Ah
210FT costs £563 each, so Bank of 3 will be £1,689; Cost per USABLE Amp (at 80% DOD) is £5.24/Ah
so the Lithiums are around twice the price to buy, but will last 3.5 times longer - so if you think you will get to the point of using over 4,100 cycles, then Lithium is the winner on cost
Caveat: 4,100 cycles are a lot though. if you were to use over 300Ah a day every day, it would take over 11 years to get to that point!
£5.25/Ah is still not a cheap cost. comparing against a basic common "Leisure" Battery, that could be £100 for a 100Ah battery, so just £2.00/Ah - much cheaper! But those batteries have a very low cycle count. If you took one of those down to 50% DOD each day, you would be looking at changing them within the year. Works out both inconvenient AND expensive.
When looking at the cost per Ah PER Cycle, the basic cheap battery would actually be nearly 4 times the cost of the NSBs and nearly 6 times the cost of the Lithiums.
Of course, if you are a weekend use only, and use campsites with hookup a lot, then fancy expensive batteries are a waste of money basically and you may as well go cheap. The sensible cost-effective choice in that situation
Space and Weight
As we all know, Lithiums are a lot lighter and take up less room
the 4 x RB100 will weigh just 54Kg; the 3 x NSB 210FTs will be 210Kg. For me, that weight makes no difference as I have plenty of Payload. a lighter van might well have a different outcome
Space wise - you would take around half the physical space. Again, ok for me with the bigger batteries, but could be different for others.
Conclusion
For my requirements, the Northstar NSB 210FT Blue+ make the most sense out of the two options as it is very likely the lifecycle count 2050 will outlive my needs, let alone the 7000 cycles of the Lithium.
As it happens, both the RB100 Battery and the Northstars were used batteries and the cost of the 210FTs per Ah were less than a basic cheap "Leisure" battery, so if anyone does wonder about the wisdom of paying even £5.25/Ah, I didn't
Would I buy the Northstar NSB 210FT Blue+ batteries again? or would I get Relion RB100 Lithiums?
The For and Against for both for MY specific requirements...
Costs
Got 3 x NSB 210FT Blue+ Batteries. They provide a total of 645Ah (@C20) - That is a usable 322Ah at 50% DoD (they can go safely lower if need be, but we will stay with 50%
If I got 3 x RB100, I will get 300Ah usable if I take them down to 100% DOD, but that will significantly hurt the life, so let's get 4 x RB100 Units - 360Ah usable at 80% DoD, but with flexibility to go lower it need be.
At 50% DoD, the NSB 210FTs have a Discharge/Charge Cycle of 2050
At 80% DoD, the RB100s have a Discharge/Charge Cycle of 7000 until they drop to 70% capacity (so let's just say 7000)
RB100 costs £900 each, so Bank of 4 will be £3,600; Cost per USABLE Amp (at 80% DOD) is £11.25/Ah
210FT costs £563 each, so Bank of 3 will be £1,689; Cost per USABLE Amp (at 80% DOD) is £5.24/Ah
so the Lithiums are around twice the price to buy, but will last 3.5 times longer - so if you think you will get to the point of using over 4,100 cycles, then Lithium is the winner on cost
Caveat: 4,100 cycles are a lot though. if you were to use over 300Ah a day every day, it would take over 11 years to get to that point!
£5.25/Ah is still not a cheap cost. comparing against a basic common "Leisure" Battery, that could be £100 for a 100Ah battery, so just £2.00/Ah - much cheaper! But those batteries have a very low cycle count. If you took one of those down to 50% DOD each day, you would be looking at changing them within the year. Works out both inconvenient AND expensive.
When looking at the cost per Ah PER Cycle, the basic cheap battery would actually be nearly 4 times the cost of the NSBs and nearly 6 times the cost of the Lithiums.
Of course, if you are a weekend use only, and use campsites with hookup a lot, then fancy expensive batteries are a waste of money basically and you may as well go cheap. The sensible cost-effective choice in that situation
Space and Weight
As we all know, Lithiums are a lot lighter and take up less room
the 4 x RB100 will weigh just 54Kg; the 3 x NSB 210FTs will be 210Kg. For me, that weight makes no difference as I have plenty of Payload. a lighter van might well have a different outcome
Space wise - you would take around half the physical space. Again, ok for me with the bigger batteries, but could be different for others.
Conclusion
For my requirements, the Northstar NSB 210FT Blue+ make the most sense out of the two options as it is very likely the lifecycle count 2050 will outlive my needs, let alone the 7000 cycles of the Lithium.
As it happens, both the RB100 Battery and the Northstars were used batteries and the cost of the 210FTs per Ah were less than a basic cheap "Leisure" battery, so if anyone does wonder about the wisdom of paying even £5.25/Ah, I didn't
wildebus
Forum Member
This is something I need to look at as mine only puts out 45A (meant to be rated at 85A I think?) and if more is demanded, what seems to happen is the voltage drops, cutting out the B2B. I don't know whether this drop is by design within the regulator or not, but either way I think I need to probably replace it with a higher output unit (think there may be an optional 120A one I can fit?)
SquirrellCook
Forum Member
You may be able to fit a new regulator pack. I carry one as a spare.
An interesting read Dave. Thanks for all the hard work. Though if you were to look at real world numbers with the assistance of your solar help your batteries will have much less of a hammering. I’m still torn over what to treat Betty too. For now I have some old Varna’s for testing.
An interesting read Dave. Thanks for all the hard work. Though if you were to look at real world numbers with the assistance of your solar help your batteries will have much less of a hammering. I’m still torn over what to treat Betty too. For now I have some old Varna’s for testing.
ScoTTyBEEE
Forum Member
Or instead of paying £3600 for 400ah of relions you could pay around £1000 for 560ah of prismatic cells, add a £50 bms and go spend your saved £2600 on a holiday. £2.23 per usable 80% ah changes things.
www.alibaba.com
Have a read here if you're interested in the quality and reliability of the cells and company: https://diysolarforum.com/threads/xuba-electronics-deal-280ah-lifepo4-cells-purchase-review.3850/
Szxuba Grade A Eu Stock Rechargeable 3.2v 280ah Lifepo4 Lithium 280ah Energy Storage Battery Cell - Buy Lifepo4 280ah Battery eu Stock 280ah Lifepo4 Battery Cell lifepo4 280ah Product on Alibaba.com
Szxuba Grade A Eu Stock Rechargeable 3.2v 280ah Lifepo4 Lithium 280ah Energy Storage Battery Cell - Buy Lifepo4 280ah Battery eu Stock 280ah Lifepo4 Battery Cell lifepo4 280ah Product on Alibaba.com
Have a read here if you're interested in the quality and reliability of the cells and company: https://diysolarforum.com/threads/xuba-electronics-deal-280ah-lifepo4-cells-purchase-review.3850/
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wildebus
Forum Member
This would be worse case. Imagine wilding in the Winter and stationary .....
I have never had my batteries below around 70% from memory
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wildebus
Forum Member
Alibaba prices are typically unlanded and don't include VAT or Input duties. That also changes thingsOr instead of paying £3600 for 400ah of relions you could pay around £1000 for 560ah of prismatic cells, add a £50 bms and go spend your saved £2600 on a holiday. £2.23 per usable 80% ah changes things.
Szxuba Grade A Eu Stock Rechargeable 3.2v 280ah Lifepo4 Lithium 280ah Energy Storage Battery Cell - Buy Lifepo4 280ah Battery eu Stock 280ah Lifepo4 Battery Cell lifepo4 280ah Product on Alibaba.com
Szxuba Grade A Eu Stock Rechargeable 3.2v 280ah Lifepo4 Lithium 280ah Energy Storage Battery Cell - Buy Lifepo4 280ah Battery eu Stock 280ah Lifepo4 Battery Cell lifepo4 280ah Product on Alibaba.com
Have a read here if you're interested in the quality and reliability of the cells and company: https://diysolarforum.com/threads/xuba-electronics-deal-280ah-lifepo4-cells-purchase-review.3850/
ScoTTyBEEE
Forum Member
Very true, pot luck sometimes where duties are concerned.Alibaba prices are typically unlanded and don't include VAT or Input duties. That also changes things
wildebus
Forum Member
It would be a bit of a shock to get the extra bill!
You generally get a bit luckier with AliExpress, but the size of the package might attract Excise and Customs
There are some European distributors of DIY options which can be interesting, but you would have a very limited warranty on the DIY route and also it would need the knowledge to build them - and build them right. Most people would not want to take that on.
But as I said, this was a comparison of two specific products. There are thousands of options out there to explore, drop in or DIY.
You generally get a bit luckier with AliExpress, but the size of the package might attract Excise and Customs
There are some European distributors of DIY options which can be interesting, but you would have a very limited warranty on the DIY route and also it would need the knowledge to build them - and build them right. Most people would not want to take that on.
But as I said, this was a comparison of two specific products. There are thousands of options out there to explore, drop in or DIY.
Squiffy
Forum Member
Yes it's the same for Ali Express, I was considering buying a Double din Radio/Nav from Ali for a Ducato for £297 but when I added import duty and Vat it made the risk of buying direct from China not worth it. PhilAlibaba prices are typically unlanded and don't include VAT or Input duties. That also changes things
wildebus
Forum Member
It was fun watching Phil move them
Seriously, They are heavy but they are seriously good and for my own application I suspect they are actually better than Lithium.
I have the one RB100 battery (which was used and £4/ah if using at 100% DoD) and that - assuming life goes back to normal sometime - will be very handy as a portable battery pack in my Gazebo.
I think Lithium is starting to reach prices that are starting to make sense for general fitment, but still only for off-grid regular campers, not just weekenders or site users.
I personally would not recommend anyone goes down the DIY route of building their own Lithium battery packs. Not that there is anything wrong in doing that, but if they are asking if they should, they are likely not ready for what else is needed on top of the battery themselves. It's a lot more involved than just bolting a few parts together.
Nabsim
Forum Member
Can’t remember the name of the forum now but I did quite a lot of reading on a US yacht related forum of a company who have done lots of their own research and testing into power and lithium. I don’t have the brands or systems they do as a system would cost more than my van but they had good advice. Think you need to do a good bit of research unless money isn’t a hurdle. Folks have been using power in boats a lot longer than we have though so lots of info.
I don’t think a lot of people could use your battery’s Dave, to get the same usable capacity I have now it would be over 300kgs wouldn’t it? That versus 26kgs lol
Or are yours 69kgs each, almost 280kgs.
I don’t think a lot of people could use your battery’s Dave, to get the same usable capacity I have now it would be over 300kgs wouldn’t it? That versus 26kgs lol
Or are yours 69kgs each, almost 280kgs.
SquirrellCook
Forum Member
I did some reading last night and came across some boaty lithium testing and I think it's going to be four T105's for Betty.
Nabsim
Forum Member
You have to go with what suits you best, unfortunately it can be costly finding that put though lol
wildebus
Forum Member
I understand you have 200Ah usable at 100% DOD? (2 X 100Ah Batteries total weight 52Kg?) I have 315Ah usable at 50%DoD, at 210Kg total weight.
To get Lithium's with around same usable capacity going down to say 80%, that would be 100Kg, so the difference is a lot less.
Nabsim
Forum Member
Yes to the capacity but no to the weight, each of my battery’s weigh 13kgs so total is 26kgs. The Bosch PowerFrames they replaced weighed 26kg @ 90ah And I had 3 of them