Lithium hybrid, for beginers.

[pcatterall]

My neighbour in our Spanish marina has to replace his gel domestic batteries about 250ah I believe.
He had been contemplating lithium but had been put off by safety concerns and the thought of having to install new type chargers and alternator.
I understand that a simpler option may be for him to retain his good starter battery and charging set up, buy lithium domestics and charge them with a b2b charger.
Before I say anything to him can I ask forumites for their opinions? Some approximate costs would be appreciated.
Thanks

 

[Minerva]

That is my loose thinking too - a lead acid starter battery, with a dedicated shore power charger and to which the alternator is solely connected. Betwixt that and the domestic LifPo4 side there would be a b2b charger to take alternator power once starter back being full. All solar via an MPPT charger only too the LiPo4 side would be connected.

That way you don't have to muck about with changing the alternator and it won't blow up with the BMS shuts down. Both banks can have their own battery chargers with the specific profile; let's face it shore power battery chargers are both pretty cheap and small so easy to fix two in parallel. As I understand it, if you have wind gen then that will want to go to the lead starter battery too as not many wind chargers have LiPo4 charging profiles.

For what it's worth, I've not done this yet - but I am in the process of negotiations to buy a boat which needs batteries so I've been doing some digging about into this as I'll likely have to do an install next month as my hand is being forced.

 

[roaringgirl]

Alternative to a new alternator is a configurable external regulator with a LFP option (eg. Balmar) and re-configuring the charge controllers on your other sources.

 

[geem]

That is my loose thinking too - a lead acid starter battery, with a dedicated shore power charger and to which the alternator is solely connected. Betwixt that and the domestic LifPo4 side there would be a b2b charger to take alternator power once starter back being full. All solar via an MPPT charger only too the LiPo4 side would be connected.

That way you don't have to muck about with changing the alternator and it won't blow up with the BMS shuts down. Both banks can have their own battery chargers with the specific profile; let's face it shore power battery chargers are both pretty cheap and small so easy to fix two in parallel. As I understand it, if you have wind gen then that will want to go to the lead starter battery too as not many wind chargers have LiPo4 charging profiles.

For what it's worth, I've not done this yet - but I am in the process of negotiations to buy a boat which needs batteries so I've been doing some digging about into this as I'll likely have to do an install next month as my hand is being forced.

You don't need two shore power chargers. If you fit a B2B. One battery can charge the other. If you are on shore power you turn wind gen off. Off shore power, the wind gen charges the domestic bank only. No point in putting it into an engine battery that has minimal load. In my experience, wind turbines output so little they won't charge up your batteries when living aboard because fridge loads etc are larger than their output. They just reduce how low the batteries drop.
In addition. Work out what you will do if the lithium bank drops out due to a BMS shutdown or fault. Can you run the boat and get home on your engine battery? If not, what will you do?

 

[Baggywrinkle]

Separate the Lithium leisure batteries from the starter/alternator with a B2B ... like in this schematic

https://www.victronenergy.com/uploa...mart-Battery-protects-MPPT-Orion-Tr-smart.pdf

 

[roaringgirl]

You don't need two shore power chargers. If you fit a B2B. One battery can charge the other. If you are on shore power you turn wind gen off. Off shore power, the wind gen charges the domestic bank only. No point in putting it into an engine battery that has minimal load. In my experience, wind turbines output so little they won't charge up your batteries when living aboard because fridge loads etc are larger than their output. They just reduce how low the batteries drop.
In addition. Work out what you will do if the lithium bank drops out due to a BMS shutdown or fault. Can you run the boat and get home on your engine battery? If not, what will you do?

Sail?

 

[Minerva]

You don't need two shore power chargers. If you fit a B2B. One battery can charge the other. If you are on shore power you turn wind gen off. Off shore power, the wind gen charges the domestic bank only. No point in putting it into an engine battery that has minimal load. In my experience, wind turbines output so little they won't charge up your batteries when living aboard because fridge loads etc are larger than their output. They just reduce how low the batteries drop.
In addition. Work out what you will do if the lithium bank drops out due to a BMS shutdown or fault. Can you run the boat and get home on your engine battery? If not, what will you do?

Wind gen direct into domestic - not many chargers seem to have a lipo4 setting (that I’ve seen). So it going into the starter will provide trickle charge when boat is unattended on mooring to ensure full off beans when I arrive on a Friday night. Can’t say I’d probably buy a wind genny today, but the boat I’m looking at has one, so…

As for powering the main bus bar with the starter and similarly the starter motor with the domestic bank, a pair of normally off breaker switches should solve that without much ado.

 

[Trident]

Also if you look at some of the good so called drop in batteries like Renogy (I have 7 on my boat and have fitted dozens and dozens now without issue - even Will Prowse loves them) they have a really good built in BMS in each battery. Please note most brands have a crappy BMS with very little protection but Renogy, Battleborn etc have BMS with big wires and proper protection levels so do your homework.

So in the event of a BMS fault it should only be on one battery in the bank and the others will still work. Normal cut offs for over charge etc self correct when the situation changes but here I'm talking about a BMS fault where the electronics die for no normal reason. Unless you plan to only install one LiFePo4 you shouldn't need to worry about crossover switches etc to the FLA. An abundance of caution might suggest a set of jump leads though...

 

[Minerva]

Also if you look at some of the good so called drop in batteries like Renogy (I have 7 on my boat and have fitted dozens and dozens now without issue - even Will Prowse loves them) they have a really good built in BMS in each battery. Please note most brands have a crappy BMS with very little protection but Renogy, Battleborn etc have BMS with big wires and proper protection levels so do your homework.

So in the event of a BMS fault it should only be on one battery in the bank and the others will still work. Normal cut offs for over charge etc self correct when the situation changes but here I'm talking about a BMS fault where the electronics die for no normal reason. Unless you plan to only install one LiFePo4 you shouldn't need to worry about crossover switches etc to the FLA. An abundance of caution might suggest a set of jump leads though...

Good to hear positive things about renology. They look completely priced and have a really good / informative website. I was being drawn to them as preferential supplier.

 

[sailaboutvic]

Peter your friend shouldn't have any safely issues, lithium are much safer then LA as already said a B2B is the most cheaper way to go just keeping a LA starter battery,
He need to make sure his lithium are not connected to his alternator and are only charged though his B2B or solar .
As I have posted before there a school of tho that using a longer charging wire from the alternator to lithium will stop the alternator from over heating ,
I have two friends now using this method, it be interesting to see how they get on with it .
For now I suggest a B2B in this way he wont have to change his shore charge too.

 

[Trident]

Good to hear positive things about renology. They look completely priced and have a really good / informative website. I was being drawn to them as preferential supplier.

Full disclosure I am a dealer for them - by choice and by recommendation. I did a lot of research and basically for batteries found Renogy to be second only to Battleborn (and a very close second) but Battleborn don't export to the UK easily. The other good thing with Renogy is the sheer size of the range they have for solar and charging specifically designed for Lithium. If you do decide you want anything from them in the UK, PM me and I'll see if I can sort out a discount for you

 

[Poey50]

Also if you look at some of the good so called drop in batteries like Renogy (I have 7 on my boat and have fitted dozens and dozens now without issue - even Will Prowse loves them) they have a really good built in BMS in each battery. Please note most brands have a crappy BMS with very little protection but Renogy, Battleborn etc have BMS with big wires and proper protection levels so do your homework.

So in the event of a BMS fault it should only be on one battery in the bank and the others will still work. Normal cut offs for over charge etc self correct when the situation changes but here I'm talking about a BMS fault where the electronics die for no normal reason. Unless you plan to only install one LiFePo4 you shouldn't need to worry about crossover switches etc to the FLA. An abundance of caution might suggest a set of jump leads though...

Yes, multiple LFP batteries in parallel go a long way to manage the sudden blackout problem if there is a BMS shutdown. However you do need some means of knowing if a battery has dropped out since other functioning batteries wil conceal the loss. An MRBF fuse on each battery may well give sufficient amperage interupt capacity to avoid the expensive and hard to obtain Class-T fuses as well as protecting cabling all the way from the battery terminal. The downside of this arrangement is that you give up fast charging from the alternator if connected direct to the LFP but that comes with a higher initial outlay and may not be necessary for those with plenty of solar and / or mains charging.

 

[geem]

Sail?

Not really the issue. The engine will run and the alternator will charge the engine bank. You have autopilot, instruments, fridge, navigation lights,. They run on the domestic battery. That is why I said work out what you will do