HELP - Leisure Battery Low in AM

Red_48 said:
The Wallas XC Duo consumes 8-10A for 5-10 minutes during startup. Then 0.55-0.85A thereafter.

We've already set the Dometic CRX65 to its lowest setting (1.14 Ah/h at +25°C ambient).

If the battery is, as everyone seems to agree, dead. I need to replace it with a unit that will better cope with these demands.

Both my Sterling 'Pro Batt Ultra' Battery-To-Battery Charger 12V/12V 30A and Victron SmartSolar MPPT Charge Controller 100/30 have settings for Lithium-ion batteries.

The question is, would Lithium-on be most suited given its faster recharging rates?

I want to avoid replacing the battery and adding a small generator, only to be left in the same position in a years time.
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Those "demands" are nothing, your 250Ah battery will cope with them without breaking into a sweat. :) I don't think they have directly caused to the early demise of your current battery. My guess, apart from it being an AGM and they don't by all accounts last long in some MHs, is you have let it run flat too often. I won't let our batteries fall below 12 volts and would start to get worried at 12.2 volts.

As I mentioned in another post you really need to fit a battery monitor and then never let the battery drop below 50% capacity and if you can keep it above 70% it will last even longer. If you plan on going away in January I suggest getting a straight wet cell replacement, something like the one below. A gel would be better but the price will be more. Change to Lithium if you want but I don't think it is essential.

www.tayna.co.uk

LFD230 Varta Professional Dual Purpose DC Leisure Battery 230Ah (930230115)

LFD230 VARTA Professional Dual Purpose Leisure Battery <i>Innovation with Purpose, Premium Experience, Powerful History</i> VARTA was founded in 1887 Germany, and was established fully in 1904 by delivering the first electric vehicle battery, famously driven by Thomas Edison. Soon after, VARTA...
www.tayna.co.uk www.tayna.co.uk
 
Buy in UK, and have a invoice you can get back to, if needed.
I bought ultramax, there is relion, TN power, etc and of course victron them self’s. The last edition black case from victron has bms inside, unlike the blue ones.
 
Thank you all :xsmile:
 
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Red_48 said:
I was afraid that might be the case. This morning reading is 10.64v!

Is this a suitable replacement?
www.aliexpress.com

Waterproof 12V 100Ah 120Ah 130Ah 150Ah Lifepo4 battery BMS with bluetooth for 1200w solar system motor home boat RV +10A charger - AliExpress 44

Smarter Shopping, Better Living! Aliexpress.com
www.aliexpress.com www.aliexpress.com
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I don't think so. It states 10A for the charge current, which is not a real value for a LiFePO4 battery. I would not spend my money on that.
Without going for the high-end, there are interesting mid-range suppliers based in Europe, meaning they have to follow the European laws.

Examples:
They use Chinese suppliers, but in case you have a problem, you're in contract with a European company, much easier to sort out. What I know of these companies: I met LionTron at the Düsselfdorf Caravan Salon. Got a demo of the app, it does work :D. The batteries appear well made, solid. The BMS manages sub-zero temperatures properly and the specs appear to be realistic. I am a satisfied customer of Offgridtec for a solar panel, they are a serious company, including after the sale.
 
I'll put my tuppence worth in, I have 2 x 100ah gel batteries charged by 2 x 100w solar panels through a 20a PWM charge controller. I fitted my system 2 years ago but only been using it to draw power for about a year, poor timing by me. I run a water pump, lights- 6 x 1 amp leds and a 0.5 led reading lamp and charge all my devices every day. !2v TV, laptop, drone batteries etc. I only use a small 1000w inverter for the laptop but doesn't appear to draw too much power.
Anyway my battery monitor never shows below 12.4v just now. I'm still getting a solar charge up to 13.8v during the short time we've got light. I need to get the batteries on a good charge to get them up to full charge, just for my peace of mind. I'm not sure if leaving them at 13.8 is detrimental to their longevity, I think it might be as I'm not getting a full charge.
I've never ran out of power and I'm a bit paranoid about going too low so I really watch my consumption.
Don't know if this helps

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Red_48 said:
Any suggestions for a super quiet one?
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That does not exist, despite what the advertisement says.

If you need one after going to lithium, with a B2B and solar, then I'd look at the load.

Dometic says your fridge should need about 0.5 kWh/24h. That's about 50Ah per day at 12V. That's a lot, it is more than all your other loads combined.

At the same time, you appear to be moving quite a lot (140 spots in 275 days).

I see your B2B charger is protected with 40A fuses. If its capacity is less than 40A, you could replace it with a stronger one. because that is a bit low given your load in my opinion. The Schaudt one goes up to 70A. But let's say you charge a lithium at 50A, in 2 hours of driving you still get more than what you'd need for a day.
 
With a B2B and Li, you will not need a genny unless, you stay put for long.
I average 70-80ah daily with few more loads than you but a CRX50 instead. My best solar production was 1.6kwh a day. I still haven't fitted my B2B yet. Is in the box. EHU only used when needed and if available. Most of time off grid. The beauty of Li is you can spend weeks with partial state of charge.
 
Raul said:
The beauty of Li is you can spend weeks with partial state of charge.
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That's essential info, Thank You!

If I invest in 2x54Ah LiFePo (best fit in the space) and a BVM 712 to keep a close watch I might be able to avoid a genie (provided we keep moving).

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That allows for no reserve capacity, and will force you to drive 2 hrs daily if no sun. If that’s ok with your need that’s fine. Otherwise stretching the Li to 200ah will give you good reserve, less depth of discharge/ longer battery life, and no need to upgrade for years, even if your loads change with time. A 200ah weighs about 26kg and you can use 180ah with no damage at all. You can make it of two 100’s and still save space over the Pb.
 
Raul said:
you can use 180ah with no damage at all.
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So the useable capacity of a LiFePo is 90%? So 108Ah would give me close to 96Ah, of which our fridge running 24/7 takes 50Ah. Leaving us 46Ah.

If we don't drive for 2 hours that day we'll deplete our reserve and will need a genie. Correct?
 
£1000 plus $140 for the BMS just after Christmas :xsad:
 
Red_48 said:
£1000 plus $140 for the BMS just after Christmas :xsad:
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Well, the good generators are not cheap either. Your problem is actually your fridge, it takes a lot of electricity and it has to come from somewhere.

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Corect. A LFP with good bms can be cycled almost 100%. But, the More time you spend on full (14.4v) and on empty below 12v the more it degrades.
A good practice is to cycle no more than 80%, never charge to full and never take it below 12v.
I cycle from 12.60 to 13.65v max. I never charge above 13,7v despite what the manufactures tells you.
Most off griders with lfp do not fully charge.
 
pappajohn said:
Your alternator is rated at its max output and it won't be 'strained' as the B2B will be below that amp rating.
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If I also upgrade the Sterling B2B from a 30/12 to a 60/12 will I need an uprated alternator for my Sprinter CDI 313 2013?

Looking at many of the choices at BatteryMegastore.co.uk I see most of of battery pairs are sold with a 60/12 B2B.

I'm concerned my 30/12 won't be enough to fast charge two 100Ah or 84Ah LiFePo4 batteries.
 
I hope I'm still on topic with this question.
We have only one leisure battery a 90ah Varta. We've been told it's impractical to fit a second leisure battery due to space constraints. We have a 120 watt solar panel with a PWM controller. Would the best way for us to increase our off-grid ability to buy a lithium battery to replace the Varta?
 
Ingwe said:
I hope I'm still on topic with this question.
We have only one leisure battery a 90ah Varta. We've been told it's impractical to fit a second leisure battery due to space constraints. We have a 120 watt solar panel with a PWM controller. Would the best way for us to increase our off-grid ability to buy a lithium battery to replace the Varta?
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Yes, Lithium would double your capacity but you will also probably need to upgrade your mains charger, fit a decent solar regulator and a B2B to make full use of the Lithium battery.
 
I've got a 60 amp B2B and it pushes out quite a lot of heat when it is working at full chat. Not a problem providing it isn't in a confined space. You just need to choose where you put it in the vehicle so it can get some air flow.

Some models of B2B have alternator temperature sensors.

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Red_48
There was a video on FUN recently about batteries tested to destruction continually charging then discharging down to 10.5v that I can't find now that made me seriously consider my next battery to be lithium. My van is laid up on my drive and I have 200w solar and 200ah wet acid bats that in this presently dull winter weather dropped my leisure and cab bats down to 11.7 and 12.2v respectively so had to use EHU. I suspect that the drain to the leisure bat could have been a heater element in the empty fresh water tank clicking on and off when the outside temp falls to 4deg? I have now isolated it. This has prompted me to seriously consider Lithium next time.

Saw a very well priced Lithium 100ah battery from Towsure under £800!
 
DBK said:
I've got a 60 amp B2B and it pushes out quite a lot of heat when it is working at full chat. Not a problem providing it isn't in a confined space. You just need to choose where you put it in the vehicle so it can get some air flow.

Some models of B2B have alternator temperature sensors.
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No problem there. The current 30/12 B2B has plenty of space around it and heat can rise out into the van.

Did you need to upgrade the alternator to accommodate the extra draw from the 60A B2B?
 
vin0114 said:
Red_48
There was a video on FUN recently about batteries tested to destruction continually charging then discharging down to 10.5v that I can't find now that made me seriously consider my next battery to be lithium. My van is laid up on my drive and I have 200w solar and 200ah wet acid bats that in this presently dull winter weather dropped my leisure and cab bats down to 11.7 and 12.2v respectively so had to use EHU. I suspect that the drain to the leisure bat could have been a heater element in the empty fresh water tank clicking on and off when the outside temp falls to 4deg? I have now isolated it. This has prompted me to seriously consider Lithium next time.

Saw a very well priced Lithium 100ah battery from Towsure under £800!
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Your 200W of solar should keep the leisure batteries fully charged even in the winter if you just, as you have, isolate any unnecessary loads like the tank heater. I suggest see how things go after giving it 24 hours minimum on EHU to fully charge the batteries.

If the leisure batteries continue to discharge they may have reached the end of their life - but give them time to prove they still have some life in them first. :)
 
DBK said:
Your 200W of solar should keep the leisure batteries fully charged even in the winter if you just, as you have, isolate any unnecessary loads like the tank heater. I suggest see how things go after giving it 24 hours minimum on EHU to fully charge the batteries.

If the leisure batteries continue to discharge they may have reached the end of their life - but give them time to prove they still have some life in them first. :)
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ta DBK, will do. Never had this problem last Winter - same van so hopefully down to exceptionally low light.
 
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Red_48 said:
I'm concerned my 30/12 won't be enough to fast charge two 100Ah or 84Ah LiFePo4 batteries.
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I'm guessing the sales folk will recommend upgrading the B2B to 60A (providing the OEM alternator is up to the task) . Will report back on Monday.

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So reporting back on my experience with BatteryMegastore.

Piers was very helpful and advised not to upgrade to the 60A B2B. I bought 2x 84Ah LiFePo4's and the Victron BMS-712 with the 30% discount offered to MHFUNsters.

As I needed additional cabling (BMS shunt required larger diameter terminals and I was connecting two batteries) he provided advice, custom length cables, and tools to allow me to complete the work in their carpark.

Piers even helped me set up the B2B and MPPT to output the correct voltage for the new LiFePo4's and didn't charge us for the 2 meters of 50mm cable and terminals!

After running the Dometic CRX65, 1x cell phone 1x laptop on charge overnight, and Wallas diesel heating for 1 hour before lights out we were left with 94% capacity at 7am this morning.

Couldn't be happier

Screenshot_20191231-072139.png
 
Depending how your existing B2B is connected up the BMS may not pick up the charging current from it. If this is the case it means after a bit of driving the BMS won't accurately know the state of the batteries but after a short while at rest it will work it out. Mine does anyway. :)
 
Both the B2B and BMS are connected on the negative busbar (BMS positives are connected to each of the individual batteries).

Here's what it looks like now

Sprinter_Electrics.png
 
Red_48 said:
Both the B2B and BMS are connected on the negative busbar (BMS positives are connected to each of the individual batteries).

Here's what it looks like now

View attachment 354752
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That's how I should have done it! :) But in my defence the instructions which came with the B2B were pretty useless when it came to MH installations with a BMS and it took me a while to work out how it should be wired.
 
I initially added the BMS between the two battery's :blusher: but Piers pointed out that I wouldn't get an accurate reading with that.

Now I can obsessively check the health of the batteries ::bigsmile:

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