How much is too much Lithium

[Fatboy]

Hi Funsters, so looking at upgrading my new 22 model Kontiki, I've asked about B2B which ill fit and updating Solar but thinking of it the cost of Lithium is coming down. Fogstar for example I can get 560a/h (two batteries) of Lithium for £1600, yes its expensive but its a bargain to what they were a year or two ago. We off grid at rallies all the time so I never use EHU, I have a 2kw inverter for hair dryer (800w) and other hair accessories I have no idea what they do, TV is on a lot too. I have the space and payload so, given that we only ever spend 3 to 5 days away even without charging, then more capacity might be the way to go?

Can anyone see any issues, I am told from Sergent the charger is compatible, ill probably fit a vicron B2B and change the solar regulator to victron. The thing is brand new so when its done its done for the next few years I hope.

Nidge

 

[Terry]

Only problem I can foresee is there is no way a Sargent charger will do 560amphr of battery —— be lucky if it managed just one of your two batteries

 

[Fatboy]

Only problem I can foresee is there is no way a Sargent charger will do 560amphr of battery —— be lucky if it managed just one of your two batteries

Isn't it just a time thing, the more capacity the longer it takes if it's a 30amp changer 10 hrs for 300 amp? or am I missing something.

 

[funflair]

I suppose it's only too much if you are never going use much of it, if you were always on hook up 560ah would be too much and indeed any lithium would be a waste, we have 640ah and might get down to 30% after 5 or 6 days in the winter so do we have too much? in the summer yes possibly but in the winter no.

You need to try to look at your current and projected usage but I think the old rule of "the more you have the more you use" might start to apply.

 

[eddie]

The only disadvantage of "too much Lithium" is that it is a waste of money if you can't charge them correctly

I only have 360Ah but I have 3 x 175w for the Summer and a 120amp Buck Boost Battery to Battery charger. In addition if I do "plug in" I have a Victron 3000w/120amp multi charger so again can put a lot back in in a short time

This also works very well with the factory fitted Onan generator that I wouldn't choose/need however it is a non optaional "standard equipment" on my camper

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[Lenny HB]

IMO you can never have too much power when we get the new van I'm looking at fitting the Fogstar 460ah. Big problem with having a big battery is having the means to charge it, I'm hoping to be able to get 500 watts of solar on the roof and upgrading the 30 amp B2B to at least 60 amp maybe 90 amp.

Does your van have an upgraded alternator? If so with that size battery a 60 or 90 amp B2B would be a good investment.
For that size of battery, I wouldn't even consider using the Sargent charger you will probably burn it out as Lithium will take the max power it can until nearly charged.

Even though we use our van off grid 95% of the time I think I have talked myself into fitting a Victron Multiplus charger/inverter it makes the wiring easy the 2000va one has a 70 amp charger & the 3000va a 120 amp charger.

 

[Tombola]

Yes but you dont want a 30amp charger killing itself for the time it takes to charge 560 amp.

My attitude is if you use the power and have the money then lithium setup is the way to go, but you have to get the charge back in quick
Especially as you never use EHU. and you can always put another charger instead of the sergent Which sargent system is it? you really want a charger with a lithium profile 3 stage, not just using "gel" setting. The victron blutooth gear is good for remote monitoring, but if the batteries you are buuying have blutooth monitoring, you can see exactly whats going in and out from that.
Victron b2b fine, but if only the 30a, you can run 2 at a time or sterling do a 60 or even 100 I think? (depends on your alternator and exisiting split charge set up) the van may even come with a b2b as its new. Get plenty solar, as much as fits.

you may even get away with 280 ? see how you get on for a week or 2, then judge from there, adding another fogstar after a week wont make no harm.

 

[Fatboy]

IMO you can never have too much power when we get the new van I'm looking at fitting the Fogstar 460ah. Big problem with having a big battery is having the means to charge it, I'm hoping to be able to get 500 watts of solar on the roof and upgrading the 30 amp B2B to at least 60 amp maybe 90 amp.

Does your van have an upgraded alternator? If so with that size battery a 60 or 90 amp B2B would be a good investment.
For that size of battery, I wouldn't even consider using the Sargent charger you will probably burn it out as Lithium will take the max power it can until nearly charged.

Even though we use our van off grid 95% of the time I think I have talked myself into fitting a Victron Multiplus charger/inverter it makes the wiring easy the 2000va one has a 70 amp charger & the 3000va a 120 amp charger.

No Idea on the Alternator, I figure its just the Ducato smart alternator fitted, I didnt want to go large on a B2B because of the stress and heat generated so 30a would give me just a boost?

 

[Steve and Denise]

We have 300ah lithium 525w solar and a 30amp b2b plus a 30 amp mains charger not had the need to use ehu really this year but as you say 30 x10hr is 300 if needed

 

[eddie]

No Idea on the Alternator, I figure its just the Ducato smart alternator fitted, I didnt want to go large on a B2B because of the stress and heat generated so 30a would give me just a boost?

No point in going to such a big Lithium bank. 10 hours driving would replenish about 50% of your bank.

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[Lenny HB]

No Idea on the Alternator, I figure its just the Ducato smart alternator fitted, I didnt want to go large on a B2B because of the stress and heat generated so 30a would give me just a boost?

A lot of converters fit upgraded Alternators Hymer, Carthago etc., fit either 160 or 180 amp alternator. I wouldn't want to go above 45 amps with the standard alternator and that is not enough for 560ah of Lithium.

 

[bigtwin]

then lithium setup is the way to go, but you have to get the charge back in quick

That’s true for lead acid but not so for lithium. Lithium batteries are perfectly happy at partial states of charge.
Indeed, this fact makes them a much more suited (than LA) means of achieving endurance (i.e. endurance in days = capacity/(daily Ah usage - daily charge capacity)) without degrading battery life.

Of course, the objective of putting back in what you take out is a given but, in comparison with LA, time is not a critical factor (endurance becomes the defining factor).

Ian

 

[Bessy765]

We have a 2019 Burstner with a 180 amp alternator, 700. Watts of solar, 12/2000/80 inverter/charger and 2 x 100w Transporter Energy batteries. We find that plenty. We do not have a B2B charger and all works well.

 

[Terry]

Isn't it just a time thing, the more capacity the longer it takes if it's a 30amp changer 10 hrs for 300 amp? or am I missing something.

IS the Sargent a 30 amp charger? Don’t know about new ones but they used to be 20 - - As a rule of thumb you want 10 amp charger for 100 amp of battery so 50/ 60 amp or bigger charger required yes a 20 amp charger will take a long time to charge 560 amps of battery (if it ever gets to charge it to full capacity) but how long will your charger last at full capacity all the time?

 

[stewartwebr]

Agree with other comments, the beauty of lithium is the speed it can be charged and discharged. You can pull huge currents (within design limits) and you can throw in as much current as your system allows. Having a small 30 amp charger defeats the main benefit in my mind. Our charger can throw in 120amps and with the engine running an additional 40amps. So with both the generator and engine running I’m chucking in 160 amps and on top of that what ever my 3 solar banks can give me. But we have a very power hungry Motorhome.

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[Fatboy]

So the standard charger on a Swift Kontiki is 25a 300w, I’m plugged in right now with lead acids at around 60% it’s it’s taking 15a according to my shunt. SO, I want to upgrade to Lithium and will be looking at 300ah plus, if I don’t change my standard charger it will take a while to charge (it can charge lithium according to sergeant) if I do go for a bigger charger I don’t want to loose the feedback I get to the swift command panel, if anyone has upgraded can you keep the display?

 

[stewartwebr]

So the standard charger on a Swift Kontiki is 25a 300w, I’m plugged in right now with lead acids at around 60% it’s it’s taking 15a according to my shunt. SO, I want to upgrade to Lithium and will be looking at 300ah plus, if I don’t change my standard charger it will take a while to charge (it can charge lithium according to sergeant) if I do go for a bigger charger I don’t want to loose the feedback I get to the swift command panel, if anyone has upgraded can you keep the display?

If you choose to go down the lithium route you may find that the battery manufacturers monitoring system would give you much more detailed information than your Swift Command system. I would assume like most motorhomes the Swift Command is using a shunt monitor to measure what goes into the battery and what comes out. In reality it is a very crude system. My Buttner shunt was okay, but the Super B (Lithium battery manufacturer) monitoring system tied into each batteries individual management system is much more accurate, giving information pertinent to the individual battery. It is far superior to the information supplied in the Buttner control panel showing individual voltage, individual charge currents and remaining power.