gregcope
Well-Known Member
Got a write up?
Planning for DIY LiFePO4
- Thread starter Poey50
- Start date
Got a write up?
Mikedefieslife
Well-Known Member
Sure.
I used to run 6xT105, and they were charged by solar and the alternator via a Sterling Alternator to Battery charger. The A2B would exact around 50-60a at 14.5v all day long.
It would have been nice to keep this for the LFP bank, but unfortunately it is not customisable. Alas I sold it to a friend. Sterling themselves told me that the BB1260 was fully customisable, and would take the place of the A2B.
I've not found that to be the case. It doesn't connect to the alternator at all (only the start battery), and doesn't have any temperature sensing for alternator. I have it set up to charge up to 13.8/14 and float at 13.2/4. The voltages aren't exact due the archaic method by which it is programmed. i.e. two multifunction touch buttons and flashing lights.
I have found that even when I have a deep discharged bank the BB1260 will only get 40a from the alternator (and that is at the lower voltages). I could live with that, but it only extracts this in short bursts. Maybe 5mins at 40a, 10mins at 13a. So by the end of an hour you've got half the yield or less than would have been achieved with the A2B.
Additionally, the unit gets silly hot. Almost immediately after start-up the heatsinks are too hot to touch and the fans are going.
My only conclusion is that either mine is faulty (I've asked Sterling, but no response as yet), or it's substandard compared to the A2B, and possibly the new Victron Orion units, but they are 2x the price.
My goal is find someone to convert my spare alternator to external reg, then use the Balmar unit.
Once I have the time I will do a full write up of my setup and experiences on my blog and stick a link here if anyone is interested.
Poey50
Well-Known Member
This is very interesting to me for a number of reasons - mainly that I currently have a Sterling A2B which is a great piece of kit for boost charging my sealed lead acids. But I also took advantage of buying a second hand B2B 60amp refurbished unit from Sterling at a very good price with a view to using it for LFP. I haven't decided which unit to go with. The A2B has alternator temperature sensing as you say so that would stop it overworking my very ordinary 100amp alternator - and it does have a LFP setting although a rather high one although I could arrange for automatic disconnect via a Victron BMV712 relay. I was thinking of feeding the A2B to a Sterling low voltage loss battery splitter for both the LFP and the start batteries. That would give some protection against a high voltage disconnect as the starter battery would absorb the voltage spike.
But I was - until I read your post - favouring the Sterling B2B. I'm surprised you are having problems with it. The excellent Marine How To site drools over it, describing as the class leader in B2Bs. Had you tried increasing the customisable settings? Battleborn also recommend the Sterling B2B and give precise recommendations which are 14.4 for bulk and 13.6 for conditioning and float. (Personally I'd go for 13.4 for float which effectively prevents float.)
Sterling Pro Batt Ultra Battery to Battery Charger - Battle Born Batteries
Do let us know of any developments and I'd be interested to see your write-up in due course.
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pvb
Well-Known Member
Sterling have had a number of different B2B chargers over the years; Mikedefieslife may have one of the original ones.
Poey50
Well-Known Member
LoneHort
Well-Known Member
Well to put a bit of fat in the fire I am in discussions with a UK marine electric shop with a view to them becoming a dealer for the firefly oasis battery.
Firefly Oasis Battery - Carbon Foam AGM
Fantastic battery with most of the cycles of a lithium at a more reasonable price and much more durable. I’m willing to commit to 4 and if we get a few more we are ordering a pallet of them. Pm me for more details
Firefly Oasis Battery - Carbon Foam AGM
Fantastic battery with most of the cycles of a lithium at a more reasonable price and much more durable. I’m willing to commit to 4 and if we get a few more we are ordering a pallet of them. Pm me for more details
Poey50
Well-Known Member
Speaking as the OP, would you mind restarting this topic as a new thread? You will probably pick up more interest that way and won't then divert the aim of this thread which is to explore DIY LFP systems. Thanks.
miyagimoon
Well-Known Member
Have a look at Lithium Batteries on a Boat Facebook Page -https://www.facebook.com/groups/427372107686109/ . There is a wealth of information about LifePO Batteries, BMS's, Chargers, Inverters etc.
Poey50
Well-Known Member
Yes, I've been working backwards through their posts for a while now. With well over 4,000 members there's no shortage of interest. Easier to follow than the marathon Cruisers Forum threads. Will Prowse's DIY solar forum is also good and the information is more easily searchable.
Richard10002
Well-Known Member
No need to get anywhere near 2.5V, (10V for 4 cells).
I cycle mine between a bit below 13.4V, (4 cells at about 90% SOC), and about 12.85V, (4 cells at about 20% SOC). I get to use about 400Ah out of 520Ah.
They last me about 5 or 6 days, then I get to charge them at 60A which takes about 7 hours, (so once a week). This against charging LA batteries at least every other day, and taking 3 hours or so to get the last 10% in, no matter how depleted they were, or not.
Mikedefieslife
Well-Known Member
I believe mine is one of the slightly newer BB1260 versions that can handle re-gen braking, BMS controlled shut off, and a few other features. It came with a test sheet, so it had been physically tested before being shipped. I can't see anything wrong in my setup, so I don't quite understand the issue. I've also tried running it in 1/2 power mode but then then it doesn't put out a constant current. It wi;; be around 24amps, but then drop to 10-13amps.
I think it's cutting power to try and cool itself down. It produces masses of heat almost from the onset. Now I'm in ambients of 28c, but it was same in Winter in the canaries when it was only in the teens. The fans work, so there's not a cooling fault.
Poey50
Well-Known Member
Very helpful and a bit concerning. Thanks.
Poey50
Well-Known Member
Edit.
I wrote an earlier version of this suggesting there might be something wrong with your unit. Since then I've been digging deeper into the Lithium on Boats forum. The thread started by Helen Bell on 10.10.19 is very useful. (I can't link to it, you have to ask to join.) The main takeaway from the thread is that a Sterling B2B may be fine for smaller LFP batteries 100-200ah especially where the charging is skewed more to solar, but for any larger installations the dumb regulation of the standard alternator is a limiting factor and the upfront investment then needs to include a beefier alternator and an external regulator programmable for LFP. So £££s.
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Poey50
Well-Known Member
Browsing the Lithium Batteries on Boats Facebook group the BMS that seems to be favoured is the 123SmartBMS. I'm encouraged by that as it had previously caught my eye as suitable for my purposes. It is a European company (Dutch) and distributor (Czech) with apparently good support and documentation. They make suitable bistable relays to match. Also I love the Czech accents ... especially Michael's ...
No personal connection.
No personal connection.
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Richard10002
Well-Known Member
If I hadn’t decided to buy the second hand batteries I decided on, GWL would have been my choice for new Winstons, or Sinopolys.
Poey50
Well-Known Member
Changed my mind about posting something. (We don't seem to have a delete button.)
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Elessar
Well-Known Member
@3V
So 175 Ah as we know it.
pvb
Well-Known Member
No, 700Ah, because £3000 buys you 4 of the 3V units.