LiFepo info

[long-cours.62]

Hello all !
I have some question concerning batteries LiFepo.
I project to replace our actual service lead batteries (6 year old still do the job) 24volts 620 amps.
And I hesitate between the maximum I can fit in the box (1000mm x 1100mm)
8 x Power Queen 200 amps Lifepo 230kgs 4288€
8 x Eco-Worth 280 amps 232 kgs 4476€
8 x Ultracell 220 amps lead Gel 512kgs 3200€

The difference off weight is not a problem...after it was in the box , could be one to move to the box The difference of price between a correct Lead Gel and "average" Lifepo is not so big.

But from our second boat (47 years ago) we never had trouble with our lead batteries we kept them 7/9 year.
When I read some testimonies for Lifepo some had big trouble.

Also my question : can I keep our actual system of charge (Victron, Cat alternator, Solar panel, ISolar SMV 3KW is a new 3KVA 2400w 24Vdc)
or adapt special equipment to charge the Lifepo batteries ?
On our former "Vietnamese baby" they fit the battery you can see on the (bad) photo, anybody know this brand ?

Thanks

Thanks

 

[heysteve]

The two biggest reasons we switched to LFP was the ability to discharge to a low SOC when conditions warrant, and the ability to charge at a high rate all the way up to 90+% SOC. The latter is helpful, for example, if you need to charge your house bank off a generator.

It sounds like your current setup is working just fine and you're getting long life out of LA batteries.

If I may ask, are you trying to solve a problem or just curious about LFP?

 

[DavidM]

I would not use gel batteries. If you want to stick with lead acid batteries, use golf cart batteries wired 4 in series (to make 24 V) and two sets in parallel (to make 440 Ahs) or 12 V AGMs wired two in series and four sets in parallel.

Switching to LiFePO4 batteries requires upgrading your charger as well as limiting load on your alternators.

David

 

[long-cours.62]

The two biggest reasons we switched to LFP was the ability to discharge to a low SOC when conditions warrant, and the ability to charge at a high rate all the way up to 90+% SOC. The latter is helpful, for example, if you need to charge your house bank off a generator.

It sounds like your current setup is working just fine and you're getting long life out of LA batteries.

If I may ask, are you trying to solve a problem or just curious about LFP?

We have no problem with our actual classic lead batteries, but they are now little more than 6 year old. and as said our average use was around 8 years with lead batteries ( Fulmen 6 volts or Rolls 6 volts).
Our batteries "box is 1000 mm x 1100mm unfortunately we can't fir in the 260 amps lead batteries.
Our boat is "for sale " as you know and we want put more autonomy for a potential customer because we lived on boat for now 48 years ( the first one have no electricity) we know to manage our autonomy but not sure a potential customer.
with the ultracell 200amps we put more 33%
with the LiFepo w eco-worthy it could be + 270% ( if discharge the lead by 60% and the Lifepo by 85%)
But DavidM give the answer for me : don't want change my charger, use alternator and solar panel like actually.
It means we will stay with lead, probably the ultracell 200amps and if I found where get 40mm more the 250amps in this case it will be 67% more not bad.

 

[tiltrider1]

If your battery charger has a profile for LiFePo4 then the change over is rather easy.

If you spend extended time on inverter and then recharge with alternators there is added expenses.

At this point in time most of us connect our alternators to lead acid start batteries and then use a 60 amp dc to dc charger to the house bank. We mostly use big inverter chargers hooked straight to the house bank for charging off the generator.

So far the only negative we have found with the eco-worthy batteries is no built in heat circuit to protect from changing when to cold. Not an issue in my part of the world but a consideration for others.

As a side note, an installer had an accident while installing a bank of eco-worthy batteries last week. The job was mostly done when he accidentally dropped a wrench and dead shorted the entire bank. The BMS’s kicked in and shut the bank down. The tech recovered his wrench and 10 seconds later the BMS turned the bank back on. Not a test I would recommend but was good to hear the test was successful.

 

[long-cours.62]

90% of the time we use our solar panel ( 1200w) to charge our batteries .
Our 9 kw generator was only in use for : washing machine or cook bread.
The 17kw we never use it !
At sea the alternator do the job even if we must manage with attention because we have 4 big fan in engine room who draw a lot !

 

[Delta Riverat]

I would not change if your bank is working well.

I'm changing because my house bank is shot. As in 12 amps of draw will drag them down from 13.5 to 11.9 in a couple hours and the charger will fully recharge in 20 minutes.

The (2) 4D FLA's each weigh over a hundred pounds and the new 12V, 300AH LiFePO4's weigh 60# each. I can lift those - I'm going to have the boat yard remove the heavies.

 

[SteveK]

After many FLA house bank replacements over the years I now have the first LifePO4 bank. The best time to consider this move is when your current bank needs to be replaced. That is when it makes sense as the old way does actually work.
What is often repeated is FLA should only be depleted to 50% but not mentioned often is that the real window of operation is 50-80% SOC.
FLA has worked well because we adjusted our needs to it.
I now have a footprint of 800Ah where previously only 400Ah max was available.

 

[long-cours.62]

A colleague who built catamaran fit this brand in them.
You "built" your own battery with the wanted cell ( 100.200.500 amps) and buy one BMS for it.
For example in my case 8x550 or if I win at lottery 4x8x550 !! Could fit in the box
Of course if we don't look the price , in same space it could be 2200 amps LiFe 352 kgs or 800 amps 560kgs Lead
and available : 1760 amps max LiFepo ( 80%) and 400 amps Lead (50%).

Unfortunately $$$$ 13000€ Lifepo and 3200€ lead
Of course if we made comparison price/available amps 7.38€/amps LiFepo and 8€ Lead it become similar or even better if we use "average " quality like Eco-worth 5€ or Power queen 6.7€