Lithium Batteries - Am I missing the point

[Fraggle 22]

We met a bloke at the weekend who was singing the praises of Lithium batteries. We have motorhomed for 5 years and have 2 x 100amp hr lead acid batteries plus 100 watt solar panel. We rarely use EHU and spend most of our time on CS or THS for approx 12 weeks per season. We have never had a problem with power so I'm not sure why I would spend £900 on Lithium. I know they are lighter and more powerful but it would probably be easier to leave the wife at home than change! Any thoughts would be appreciated.

 

[davidroxburgh]

Also be aware that the amperage of the battery BMS must be greater than the output of your B2B or the input to your mahoosive inverter. Oh, don't let them get below zero degrees C then try and charge them. They dont like it uppem.

as a non technical guy is the first reference to the BMS and is that different to the battery Itself? The output of the B2b is say 50 amps on a votronic 1212-50?

Sorry if I have not got the quoting right! First time trying

 

[Tombola]

If you are happy EXCELLENT.

All I am saying is you don't have to have lithium batteries to motorhome off-grid successfully and happily...

JJ

Of course.
That's the same as saying you can live in a tent or park bench if you really want too.

It's all about needs and wants.

 

[pau1phi11ips]

as a non technical guy is the first reference to the BMS and is that different to the battery Itself? The output of the B2b is say 50 amps on a votronic 1212-50?

You did get the quoting wrong but no biggy.

The BMS is connected to the battery and then loads are connected to the BMS. This enables the BMS to shut off the load if there's a problem with the battery voltage (or single cell voltage), the temperature is too high/low or the requested current from the battery is too high.

The BMS will have a max current handling capacity and this is usually lower than what the battery can actually handle. For example: My LiFePO4 pack will quite happily put out 280A at 24V but I'm only using a 120A BMS for my DC loads.

If you're buying an off the shelf Lithium battery it will likely have the BMS inside the battery casing and the current rating on the battery itself will be what the BMS is rated for.

 

[davidroxburgh]

Thank you. The new lithium battery will be 200Ah, while the max discharge current will be 150A, the recommended charge current will be 100A, and the max charge current 150A. The new b2b will now be 490W and 30 Amps (larger one not in stock until next spring!) and the existing 1500 inverter shows "power consumption DC at Nominal Capacity of 145A and at overload 200A".

So I assume the battery and BMS will indeed exceed the b2b (Clive's comment above) but I will (as I do now) need to be vary careful using the inverter for light loads. Both the solar controller panel and the van main panel show voltage etc, so when combined with the bluetooth display from the new battery BMS, I should get plenty of warning if I am pushing things with the inverter? Indeed perhaps the BMS would stop things getting that far?

^{_{Subscribers  do not see these advertisements}}

 

[Detnor]

There are 2 vans in the storage compound I use that have taken different approaches. One has a drop in replacement, all charging profiles set to lead acid, cost him £500 and he is very happy. The van next to mine has gone down the route of new charger, solar and b2b, lithium profiles, paid £2000 and is always telling me how good it all is. I have no idea who is right but they are both happy, I still don't understand it all.

 

[deleted79651]

There are 2 vans in the storage compound I use that have taken different approaches. One has a drop in replacement, all charging profiles set to lead acid, cost him £500 and he is very happy. The van next to mine has gone down the route of new charger, solar and b2b, lithium profiles, paid £2000 and is always telling me how good it all is. I have no idea who is right but they are both happy, I still don't understand it all.

We paid £749 for 120Ah Lithium Battery Drop in with inbuilt BMS and have struggled to get the SOC below 93%. This should give us enough margin for non EHU trips during Autumn/Winter where the double whammy of fewer daylight/solar hours and more hours of lights and water pump operations etc will put the battery under more pressure. I bought the Lithium for peace of mind ...

Steve

 

[jongood]

I'm finding myself increasingly tempted to experiment with some of this.

Design Your Own LiFePO4 Solar Power System

This is a complete system solution complete with: BMS Protection Features (over/under voltage/over-current/balancing) Low Temperature Cut-off Programmable Charge/Discharge Bandwidth Settings Matched...

www.mobile-solarpower.com

Its not for cost savings and I probably could manage perfectly well with an off the shelf version but I like the idea of tailoring something to my particular requirements.

 

[pau1phi11ips]

We paid £749 for 120Ah Lithium Battery Drop in with inbuilt BMS and have struggled to get the SOC below 93%. This should give us enough margin for non EHU trips during Autumn/Winter where the double whammy of fewer daylight/solar hours and more hours of lights and water pump operations etc will put the battery under more pressure. I bought the Lithium for peace of mind ...

Same. I ordered the cells from China and built my own battery. It would be 560Ah in 12V but went with 24V so it's 280Ah. It cost £750 for the cells and about £70 for the BMS.

We've just been away for 5 days and the lowest it got was 78%. I haven't got the solar panels fitted yet so was topping up the battery with Victron Orion B2B charger (which is only 360W). We used the battery for the fridge, lights, kettle and the toaster. The induction hob isn't installed yet either

 

[deleted79651]

Same. I ordered the cells from China and built my own battery. It would be 560Ah in 12V but went with 24V so it's 280Ah. It cost £750 for the cells and about £70 for the BMS.

We've just been away for 5 days and the lowest it got was 78%. I haven't got the solar panels fitted yet so was topping up the battery with Victron Orion B2B charger (which is only 360W). We used the battery for the fridge, lights, kettle and the toaster. The induction hob isn't installed yet either

I don't have the technical knowledge to even begin to do what you have, and I worried about the bottom of the range lead acid leisure battery not surviving the evening demands [incl the drop down bed motor that I forgot to mention in my earlier post!]. So, it was 'get your wallet out' time and pay a professional to supply and install the battery to give me peace of mind, free from 'range anxiety' and to give Elaine peace of mind free from my mithering ... It's difficult to put a price on that!

Steve

^{_{Subscribers  do not see these advertisements}}

 

[pau1phi11ips]

Give Elaine peace of mind free from my mithering ... It's difficult to put a price on that!

That's kinda why I went with the electric cooking setup instead of gas tbh. I don't know anything about gas but I have a Degree in Electronics & Electrical Engineering Also prefer the "greener" option where possible.

 

[jongood]

Same. I ordered the cells from China and built my own battery. It would be 560Ah in 12V but went with 24V so it's 280Ah. It cost £750 for the cells and about £70 for the BMS.

We've just been away for 5 days and the lowest it got was 78%. I haven't got the solar panels fitted yet so was topping up the battery with Victron Orion B2B charger (which is only 360W). We used the battery for the fridge, lights, kettle and the toaster. The induction hob isn't installed yet either

I'm in the interesting position that I have 12v leisure and 24v chassis batteries with 2x alternators, I'm starting to think maybe I should ditch the 12 volt alternator , put all the storage on 24 volt get a 24 volt inverter and just run the 12 volt lights fridge etc off a dropper.

I've not long replaced the solar setup but could connect the panels in series and just need to get some new regs?

 

[pau1phi11ips]

I'm in the interesting position that I have 12v leisure and 24v chassis batteries with 2x alternators, I'm starting to think maybe I should ditch the 12 volt alternator , put all the storage on 24 volt get a 24 volt inverter and just run the 12 volt lights fridge etc off a dropper.

I've not long replaced the solar setup but could connect the panels in series and just need to get some new regs?

I must admit, it was way easier than I thought going 24V for the leisure side. The only thing I have on the 24V-12V converter is the Maxx Air fan

 

[deleted79651]

That's kinda why I went with the electric cooking setup instead of gas tbh. I don't know anything about gas but I have a Degree in Electronics & Electrical Engineering Also prefer the "greener" option where possible.

We also went mad and had a refillable gas system fitted the day before the Lithium Battery ... The July Cretin Card Bill was a real doozie! A one man attempt to kick start the UK economy, but did I get any credit for my endeavours ... . We do use a Remoska when on EHU

Steve

 

[cmcardle75]

I must admit, it was way easier than I thought going 24V for the leisure side. The only thing I have on the 24V-12V converter is the Maxx Air fan

Yes, lots of equipment is also sold for trucks, so there's no problem getting 24V fridges, USB chargers and other appliances. Although, I'd probably run a load of 12V sockets off a DC-DC for those sorts of things, as they are still easier to find.

^{_{Subscribers  do not see these advertisements}}

 

[chrisandbev]

hi,

i have got 4 200ah cells for sale if anyone is interested

 

[davidroxburgh]

What make - what model - what size - what price? Thanks

 

[andyjc]

The new b2b will now be 490W and 30 Amps (larger one not in stock until next spring!)

What make of B2B is this please?

 

[BillyKontiki]

Looking for B to B charger 30 amp victron you won’t get cheaper than KS energy.
Also Lithium battery’s.
The owner Neal is very knowledgable and helpful.

 

[deleted79651]

Looking for B to B charger 30 amp victron you won’t get cheaper than KS energy.
Also Lithium battery’s.
The owner Neal is very knowledgable and helpful.

+1 for KS Energy

Steve

^{_{Subscribers  do not see these advertisements}}

 

[chrisandbev]

What make - what model - what size - what price? Thanks

4pcs LiitoKala 3.2V 200Ah LiFePO4 battery 12V battery Lithium-iron phosphate.

i have put them on ebay for £650 for all four,, i will be happy to sell them for £500.

chris

 

[davidroxburgh]

Sorry quoting seems beyond me!

I have bought a Votronic 1212-30. It is 30 amps 490 watts. I already had a Votronic inverter and Solar Regulator and I preferred the fan rather than a heat sink. It is tiny which helps me in a PVC with little spare space.

chrisandbev thanks but not for me.

 

[andyjc]

OK thanks - just wondered if the reference to a larger capacity model was Victron or not - they only do a 30A at the moment though i guess you can double up if necessary. Seems strange though as Votronic and Sterling both do larger models and larger capacity lithium batteries are coming down in price so you'd think there would be increasing demand for more than 30A.

 

[pau1phi11ips]

OK thanks - just wondered if the reference to a larger capacity model was Victron or not - they only do a 30A at the moment though i guess you can double up if necessary. Seems strange though as Votronic and Sterling both do larger models and larger capacity lithium batteries are coming down in price so you'd think there would be increasing demand for more than 30A.

I suspect they will launch higher power DC-DC chargers when they do a re-design.

It's a bit odd their current offering doesn't support support VE.Direct communication like their solar chargers and battery monitors.

 

[BillandHelen]

OK thanks - just wondered if the reference to a larger capacity model was Victron or not - they only do a 30A at the moment though i guess you can double up if necessary. Seems strange though as Votronic and Sterling both do larger models and larger capacity lithium batteries are coming down in price so you'd think there would be increasing demand for more than 30A.

Yes, we have 2 30amp votronic “doubled up” serving 200amp lithium, works a treat, 45 amps being pumped in this morning!

^{_{Subscribers  do not see these advertisements}}

 

[andyjc]

I suspect they will launch higher power DC-DC chargers when they do a re-design.

It's a bit odd their current offering doesn't support support VE.Direct communication like their solar chargers and battery monitors.

A response from 12voltplanet to a customer review of the 30A version indicated that connectivity would be considered in a future update however Victron in the UK seemed unaware of this (or unwilling to say)

Doubling up seems an expensive option but if it works, Happy Days

 

[davidroxburgh]

Yes, we have 2 30amp votronic “doubled up” serving 200amp lithium, works a treat, 45 amps being pumped in this morning!

How was that done please? Did you do this or did a specialist do this? Are there 2. X 100 amp batteries or one 200 amp? I will have the latter.

 

[BillandHelen]

its 2 separate 100amp batteries, you can see one of the b2b at the front, the other is mounted at the back, to the left of the batteries. All very short cable runs and very neatly carried out by Roadpro.

 

[pau1phi11ips]

How was that done please? Did you do this or did a specialist do this? Are there 2. X 100 amp batteries or one 200 amp? I will have the latter.

I'm not familiar with Votronic but you can wire the 2 or more Victron B2B chargers in parallel to 1 battery without any trouble. I assume they are all OK with that. Just set the charger parameters the same and you should be good to go.

 

[davidroxburgh]

Thanks good to hear.