What voltage is too low for LiFePO4 battery

How low a voltage can a LiFePO4 battery go? We bought a used 2022 Warwick Duo in Dec 2023. It has a LIFePO4 battery. I signed up to Sargeant Alerts before collecting the van and two days before collection got an alert and the data shows 11.2 volts triggered it.

However over winter it seemed okay and I didn't pay much attention to it! In April I did one night wild on the way to Mull and the voltage dropped to 0.6V. Starting the engine brought it back up and again it seemed to recover.

Over the summer it has been fine with the solar panel doing its job. Our usage has always been on site and plugged in.

Last week whilst away with family, and the van in storage, I received alerts and the voltage went down to 11.4V three times. In the preceding week when there was a bit of sun its voltage ranged between 12.4 and 12.8v.

I am guessing from these figures that it is a dud! Whether I can blame Brownhills for letting it go flat is another question!

That looks like a dud!

Here's a quick reference guide to LiFePo4 voltage/SOC
[You must be registered and logged in to see this link.]

It doesn't matter much what LB you have.  At this time of year, if the EC700 PSU isn't shutdown whilst the motorhome is in storage and not on an EHU, the standard fit solar panel is not able to generate enough electricity to keep the LB charged due to the load on it caused by the EC700.  When the EC700 PSU isn't shutdown, there is also a risk that something else has been left on which is adding to the load on the LB.  The only load on the LB when the EC700 PSU has been shutdown should be the Sargent communications & tracker unit which shouldn't flatten a fully charged LB.

Thanks for the reminder Caraman, I must rush downstairs and turn my EC700 off.

Done mine already!

I'm surprised Sargent don't fit an automatic cut off.   .    .     .     .     .     .

I'm surprised Sargent don't fit an automatic cut off.




They did, it was called a 20amp fuse


Pete

I just checked my battery voltages. This is a Bourton with originally a (was it 600 or 800W) solar panel, but I added another 800W. The EC700 has been turned on for a week at least, most of which has been dull cloudy no sun weather. The voltages tonight were leisure 13.4 and engine 12.8v
Anyway I have now turned the EC700 off.

gassygassy wrote:I just checked my battery voltages. This is a Bourton with originally a (was it 600 or 800W) solar panel, but I added another 800W. The EC700 has been turned on for a week at least, most of which has been dull cloudy no sun weather. The voltages tonight were leisure 13.4 and engine 12.8v
Anyway I have now turned the EC700 off.

1600W and you will be powering the national grid.  I think you mean 80W 

Doh I'll have a word with myself  . It was originally 80W and I added 120W so it's 300. See, I kan do maffs, me. That's Artificial Negligence.
Anyway in the doom and gloom, the leisure battery is holding up. I guess the Mercedes base vehicle is consuming something, checking to see if all its connections to Mars are still working.

gassygassy wrote:Doh I'll have a word with myself  . It was originally 80W and I added 120W so it's 300. See, I kan do maffs, me. That's Artificial Negligence.
Anyway in the doom and gloom, the leisure battery is holding up. I guess the Mercedes base vehicle is consuming something, checking to see if all its connections to Mars are still working.

Ha ha.  The VB should be OK on the Sargent installation as all the solar charge goes to it when the EC700 is shutdown and this is normally enough to keep it fully charged during the winter.

I need to see a Specialist and book a room in a home for the bewildered. I have just been notified that my bank balance is going overdrawn, when I thought I had enough income not to do that. Looking at the statements I find that I made a  payment to my credit card, then two days later I forgot that, and paid the whole amount that was owing before the payment I had already made. I'll go to the bank and ask if they can reverse it. I have a suspicion that if I transfer money from the credit card account to the current account they will charge me for withdrawing cash.
The trouble is that when I look at my credit card statement it doesn't show payments made until the end of the month. So after I had made the part payment it didn't show when I looked at the statement.
Maybe I'll keep the overdraft and use the credit on the card to book a cruise. It will be interesting to see if the interest on the credit card is more or less than the interest on the overdraft.

You should contact your credit card company and explain what has happened. Some credit card companies do not allow their accounts to be operated "in credit" and there have been reports on Moneysaving Expert of people having their credit cards cancelled for doing it. If you present it for what it is (i.e. a genuine mistake) then I'm sure they will recommend a suitable course of action.

I've been to the bank, explained it, they said call the credit card number - it's the same bank - which I did. They were very polite and helpful and transferred all the excess from the credit card back to the current account, though it may take 3 -5 days. So it's all sorted.. What I did find out that interest on an authorised overdraft is 39.9% APR so that is about twice the cost of the credit card. To be avoided . . . . . . .
Now off to the travel agent . . . . . .  We want some warmth in our lives! There's a nice 14 day cruise from Tilbury to Madeira, tenerife etc coming soon. Maybe that will suit us. It's cheaper than staying on a UK camp site and I would rather have sunshine, swimming, 5 star dining and entertainment and a warm cabin than sitting on someone's grass in the UK.

Cruises might be good vfm especially the longer ones but, if you already own a motorhome, are they really cheaper?  I've just done an on-line check.  The cheapest inside cabin for two works out at £87.63 a night for a 16-night cruise Tilbery to Portugal and the Canaries later this month.  A 3-night cruise to Amsterdam & Antwerp works out at £190 a night.  (This is more typical of our winter motorhome trips which are normally 4 or 5 nights at a time and only on hardstandings!)   These prices include meals, entertainment and presumably the swimming pool but don't include drinks, tips, parking, transfers, wi-fi, excursions, speciality dining and insurance.

I appreciate all the pro's and con's of cruising v camping, and I have formulated a few rules for myself:
1) If a cruise is £100 a night or more, it is too expensive. There are plenty of them, but there again there are enough at £70 or £80 a night. Per person of course.
2) If a cruise goes where I could go in a motorhome, I will go in the motorhome because it will be cheaper. And I will have the motorhome with me.
3) If a camp site is more than £20 a night I won't use it. Unless for some reason I have run out of water (which by definition will happen in the UK), and I have fallen into a frizzing cold river and want a hot shower -  a Very Long Very Hot shower.

With a very very few exceptions we don't go on the excursions on cruises, you can always do them yourself for a fraction of the ship's cost. Cruise company parking costs are usually more expensive than getting there by public transport. We have been known to use Park at My Place, go there the night before, park up in the camper, get up the next morning and get on the boat and go. We have also had one cruise from Tibury where parking was free so of course we used that. We have had one free Caribbean cruise, one at £17pp a night (Southampton to Sydney), one (Southampton / Atlantic / Brazil / Falklands / Cape Horn / Chile / Peru / Panama canal / Caribbean and back) at £37 a night pp. That one I booked with P&O at about £80 or £90 a night, and a week later the travel agent in our town I used called and said call into the shop, P&O have told us to refund you £3400. That brought the cost down to £37 a night. We had one at £15, which was very odd. Tilbury to Hull, one night. It was just that they had some space on the ship and I guess they reckon they will make money on the alcohol and gift shop sales. Not from us they didn't. The price included parking at Hull before the sailing, and a coach from Hull down to Tilbury. So we drove to Hull, got on the coach, went to Tilbury, had the one night cruise and drove home. Cheaper that a meal out at our local nice restaurant.
You have to look up 'last minute cruises'. The lastest minute one we did was to phone the travel agent at 17:15 one evening, they said yes there is a cabin available on tomorrow's cruise. We went in at 09:00 the next morning with our passports etc, paid for it, got in the car, drove down to the port (Leicester to Southampton), parked in a side street somewhere nearby, walked to the ship, got on it and sailed off into the sunset. All jolly good fun. . .
We are going on a hotel holiday to Madeira in December. We couldn't go there in a camper so it's a flight and hotel. We have done two cruises there, but you only stay for a day so we want to see more of it.

Now . . . .what was the thread title? What voltage is too low for a LiFpo battery? I have no idea ..  . . .

You have taken the thread off-topic but it doesn't matter as the OP hasn't come back after the first two posts addressed his issue.

We don't cruise but at some of the prices you have quoted we perhaps should.  I'm afraid ferries have put us off it a bit but we have often thought that a river cruise would be nice where you can see the land and walk off the boat every night.

Decent sized and secure hardstanding pitches for two with an EHU, which most of us need at this time of year, and in a good location are hard to find for £20.

Back to the subject, I have an itch to fit a lithium battery and pure sine wave inverter.  But why? Is it just to jump on the bandwagon or is it justifyable? Say £710 for a battery and 2000W Renogy inverter which seems reasonable if you want to avoid unknown Chinese items. Is it worth it? I do have and would probably want to use an induction hob in the camper, but really all I need to make that work is the pure sine wave inverter as I have 200W of solar, MPPT regulator and two 110AH lead acid batteries which are currently (haha) working OK. So why do I think I need more electric rather than gas? I have a diesel heater so at the moment (in order to avoid using the word 'currently') the only saving would be the cost of the gas I use in cooking. Using the 'cruising' analogy of 'how much camping can I have for the price of a cruise?' then I could think 'how much gas can I have for the price of the inverter + lithium?'
Oh, it's all a minefield, and perhaps not worth the loss of sleep worrying. And there is a definite bandwagon rolling, about "I must have lithium because it lasts longer and is lighter". All promoted by the magazines and on-line planet savers.
I think what I do will be determined by the fact that we want to go to North Norway next summer, and whether or not there is a plentiful supply of LPG. Oops, another minefield. I don't have a refillable bottle fitted at the moment anyway. I do have a refillable bottle but a) it is too big for the locker and b) I would need to spend about £80 on a filler nozzle and pipe. I can fit two 6kg Calor bottles in (refill price £90, and only available in the UK of course) but not one 11kg refillable. Seems the thing to do is to fabricate a cage to hold the 11kg refillable . . . . . . . .