Lithium battery installation after rash purchase???

[Pete7]

So I always obsest with the need for continuing balanci of the cells. I presume that LifePO4 also need balancing?

Chris, apologies, I addressed you by your surname above, now corrected.

There can be two issues here. The 4 cells in a 12v LFP battery can go out of sinc, but modern BMSs have a balancing function during charging, normally above 3.4v per cell, though this is user adjustable. All that is needed is a good charge every so often above this voltage point to give the BMS a chance to balance the cells. Alternatively for those building their own batteries from cells, active balancers are also available.

The second issue is a state of charge (SOC) difference between two LFP batteries in parallel. It does happen but can be safely ignored because with regular use they will come back together and be good friends again. Probably down to minor differences in internal battery resistance, the resistance of cables and lugs plus switches etc.

 

[shanemax]

C

Do you have a link for a run away LifePO4 battery? Please do make sure make sure its a LifePO4 variety of lithium which is what we are discussing here.

What happens to a lead acid battery with a shorted cell that is being charged with shore power?

Kindly Google "can LifeP04 batteries go into thermal runaway" that's if you are interested in the actual facts ??? .,then after that phone as many airlines as you can and ask them if you can check in a Lithium Life PO4 battery on to their aircraft. I don't mind admitting I am wrong as long as you don't ........
Further for every kilo you place above the water line you should place two kilos below the water line.
When you think of solar panels, radar, wind generators, electric winches , dinghy's on davitts etc etc etc you need to keep weight as ballast below the water line as is reasonable.

 

[Pete7]

I have learnt a lot following this exchange. Thanks.

I think we are all learning how to make the best use of LifePo4. Certainly getting out of the habit of having to charge the batteries up at every opportunity is a difficult one to overcome. Instead just accepting that 75% is enough or waking up to find the bank at 33% isn't a problem, the sun will sort that later in the morning, so put the electric kettle on anyway. The speed at which they charge is just superb compared to flooded lead acid, full charge all the way up to nearly full rather than dramatically dropping off at say 80% with FLA. With solar it means full batteries much earlier in the day so start to look for other things to charge up or use the surplus power like bake a cake rather than have the MPPTs drop to float. Heating the calorifier with the surplus power is becoming popular, it's on the list to investigate.

Just going back to the beginning I didn't plan to install LFP but a pair of Trojan 105s, only to find they wouldn't fit under the saloon seats so needed plan B. At the same time suppliers like Sterling suddenly dropped the price from £1200 for a 100Ah battery to £700, during lockdown 1. That started the research with articles like this one:

Lithium-Hybrid

Pete

 

[Buck Turgidson]

I will be honest and say i've skipped reading lots of posts in this thread as I have a question from some of the earlier posts.
A few people have stated that not having bluetooth is a problem, if this is true then why do Victron sell their Lithium "Superpacks" without bluetooth?
They have a built in BMS with all the protection required. What advantage would bluetooth give in this case or in fact in any drop in lithium battery?

I ask because I'm contemplating having to replace my 214Ah Odyssey extreme SLA and a 100Ah Lithium would take up less room, weigh 1/4 of the SLA and give me the same reserve. Victron offer smart batteries that require an external BMS, they have a discrete cable connection and bluetooth or the SmartPacks with internal BMS and no bluetooth. Clearly Victron believe you don't need to tinker with their built in BMS.

 

[geem]

I wonder why all airline companies ban lithium batteries except as hand luggage. Perhaps they are just paranoid.
I have lithium on board in my phone, torch, laptop etc but nothing too big to throw overboard in an emergency.. I sleep on my boat a lot in the summer but do not wish to awake to a Lithium battery of 100 amps in "Thermal Runaway"
Loads and loads of examples on You Tube, Perhaps in another 10 years when they sort out the problems but lead acid with a suitable fuse are proven to be safe and below the water line add perfect ballast.

You need to do a little more research. We are talking lifepo4 chemistry. Not the same as phones, laptops or torches. That why we use it. Its safe

 

[geem]

I will be honest and say i've skipped reading lots of posts in this thread as I have a question from some of the earlier posts.
A few people have stated that not having bluetooth is a problem, if this is true then why do Victron sell their Lithium "Superpacks" without bluetooth?
They have a built in BMS with all the protection required. What advantage would bluetooth give in this case or in fact in any drop in lithium battery?

I ask because I'm contemplating having to replace my 214Ah Odyssey extreme SLA and a 100Ah Lithium would take up less room, weigh 1/4 of the SLA and give me the same reserve. Victron offer smart batteries that require an external BMS, they have a discrete cable connection and bluetooth or the SmartPacks with internal BMS and no bluetooth. Clearly Victron believe you don't need to tinker with their built in BMS.

Victron do things differently. They have batteries with an internal BMS but also need to connect to the victron system. Undoubtedly their cells are good quality. They used to used Winston cells that by reputation are the best cells you can buy, but now they have moved to a more obscure manufacturer. The specification of the new cells is identical to any good grade A cell you can buy. Somewhat inferior to Winston in my opinion. Victron now use a blue cased aluminium cell like all others. The one drawback of Winston cells is they are large for their ah rating.
If you were building a battery with Winston cells, you would be able to get away without a Bluetooth bms. Personally, I would still want one. Seeing the cells are balanced and having all the data logged in my JK BMS is a nice feature.

 

[Buck Turgidson]

You need to do a little more research. We are talking lifepo4 chemistry. Not the same as phones, laptops or torches. That why we use it. Its safe

airlines don't make a distinction.

 

[Buck Turgidson]

Victron do things differently. They have batteries with an internal BMS but also need to connect to the victron system. Undoubtedly their cells are good quality. They used to used Winston cells that by reputation are the best cells you can buy, but now they have moved to a more obscure manufacturer. The specification of the new cells is identical to any good grade A cell you can buy. Somewhat inferior to Winston in my opinion. Victron now use a blue cased aluminium cell like all others. The one drawback of Winston cells is they are large for their ah rating.
If you were building a battery with Winston cells, you would be able to get away without a Bluetooth bms. Personally, I would still want one. Seeing the cells are balanced and having all the data logged in my JK BMS is a nice feature.

the smart packs have no way of connecting to anything. they are drop in with only power terminals.

 

[KevinV]

airlines don't make a distinction.

Well the FAA does:

https://www.faa.gov/hazmat/packsafe/lithium-batteries

 

[Buck Turgidson]

Well the FAA does:

https://www.faa.gov/hazmat/packsafe/lithium-batteries

the same rules for all types just expressed as grams or Wh for size.
edit: and LIFEPO4 are lithium ion

 

[KevinV]

the same rules for all types just expressed as grams or Wh for size.

Yes, but they do make a distinction between types, so divergence of the rules for each is quite possible as the risks become better understood. It's easy to forget how new these batteries are, rules are changing all the time.

The simple fact is that lifepo4 don't suffer thermal runaway as li-ion do. It's so easy to say lead-acid are safe, but they're capable of filling a cabin with a perfect hydrogen/oxygen mix, and I've seen them explode when a charger went wrong - spraying boiling hot acid everywhere! Not safer, but a risk that we're all used to and know how to manage so we don't worry about it much.

 

[Buck Turgidson]

Yes, but they do make a distinction between types, so divergence of the rules for each is quite possible as the risks become better understood. It's easy to forget how new these batteries are, rules are changing all the time.

The simple fact is that lifepo4 don't suffer thermal runaway as li-ion do. It's so easy to say lead-acid are safe, but they're capable of filling a cabin with a perfect hydrogen/oxygen mix, and I've seen them explode when a charger went wrong - spraying boiling hot acid everywhere! Not safer, but a risk that we're all used to and know how to manage so we don't worry about it much.

LIFEPO4 are lithium ion. Class 9 dangerous goods. There is no divergence in the rules at this time.

 

[KevinV]

LIFEPO4 are lithium ion

Eh??

 

[Buck Turgidson]

Eh??

"

Eh??

The lithium iron phosphate battery (LiFePO4 battery) or LFP battery (lithium ferrophosphate) is a type of lithium-ion battery

 

[geem]

the smart packs have no way of connecting to anything. they are drop in with only power terminals.
[/QUOTE]
The Smart batteries have Bluetooth. Internal BMS with cell balancing

 

[geem]

"


The lithium iron phosphate battery (LiFePO4 battery) or LFP battery (lithium ferrophosphate) is a type of lithium-ion battery

LiFePO4 means lithium iron phosphate. It is not lithium ion. Different chemistry.
LiFePO4 batteries use lithium iron phosphate as the cathode material, while lithium-ion batteries can use various cathode materials, such as cobalt oxide, manganese oxide, or nickel

 

[Buck Turgidson]

the smart packs have no way of connecting to anything. they are drop in with only power terminals.

The Smart batteries have Bluetooth. Internal BMS with cell balancing
[/QUOTE]

yes. typo on my part. Smart vs SuperPack. The SuperPack has no coms. Inbuilt BMS with no wire or wireless data communication.

"LifePO4 means lithium iron phosphate. It is not lithium ion. Different chemistry. Like H20 isn't hydrogen or oxygen.. it's water. Different chemistry"

Sorry but according to all the online documentation I can find Lithium iron phosphate is a type of lithium -ion battery. I fully understand it uses iron phosphate as the cathode material but that doesn't mean it does't release lithium ions from anode to cathode.

 

[geem]

The Smart batteries have Bluetooth. Internal BMS with cell balancing

I didn't say that. Read post #55

 

[stav]

Thanks for all the replies and sorry I haven't participated more, just busy (newly self employed carpenter Etal.......). So reading all the discussion and talking on the pontoon I am going to give installation a go keeping one LA and having the dc 2 dc charger set to a lower charge voltage. I have the option to charger from 14v to 14.6v and thought I might set 14.2v. I think I will isolate the positives of the LA and lifepo4 with an automatic relay. Then I will monitor voltage differences and temperatures and see how I feel about the set up. The main reason for the change for me is to get faster charging. but other benefits could be being able to run the eberspacermore often and perhaps an electric kettle? Seems complicated and not a simple thing to changeover too. One thing I will be adding is temperature sensors in the battery box and on the alternator.

 

[Neeves]

I'm interested in an earlier post (and maybe a different thread - my excuse for being vague - we are travelling with challenging internet access), from (I think) geem, on battery temperature. Underlined is the simple fact that higher temperatures of the battery are not to be encouraged - so how do you cool down a battery (or anything, DC - DC charger etc) when the air temperature is 35 deg C and seawater temperature not much lower.

Obviously not much of a problem in the UK but it must be an issue in the Caribbean, maybe Med and certainly Oz.

If it was white wine I'd try a wet towel and a fan but the wet towel idea seems a bit unlikely to curry favour draped over a battery. A fan, or fans, focussed at the battery, or other component, make enough difference....?

And how much do the associated solutions actually cool a battery..... enough?

Its a potential issue that needs planning as component location, battery, might need modification.

Jonathan