Using Lithium Batteries

wildebus

wildebus

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I have always said that this idea of only charging your Lithium Batteries to 80% and then only Discharging to 20% is a load of Balony. It is often stated as the way to best look after your Lithium (LiFePO4) Batteries, but really is a nonsense.

Just came across this Video posted yesterday by Will Prowse, who a lot of people regard as THE god of Lithium and Solar and it is good to see he is dispelling this myth. Maybe more people will believe him and use the blooming batteries they bought properly and fully!

I am starting the Video at the point he discusses about charging and discharging levels .... Also watch all to the end!

Remember - Use that Battery!
LiFePO4_C&D.png
 
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When I saw the title of the YouTube video I thought "oh no, not more 'don't charge past 80% or go below 20%' stuff, but I was so pleasantly surprised had to share it :)

I also liked how he correctly stated that the weak point in a Lithium Battery is the BMS module. This is why it is so useful to have batteries which can be serviced and the BMS can be replaced (it was always daft having to throw away a perfectly viable battery due to a simple electronics failure).
 
wildebus said:
When I saw the title of the YouTube video I thought "oh no, not more 'don't charge past 80% or go below 20%' stuff, but I was so pleasantly surprised had to share it :)

I also liked how he correctly stated that the weak point in a Lithium Battery is the BMS module. This is why it is so useful to have batteries which can be serviced and the BMS can be replaced (it was always daft having to throw away a perfectly viable battery due to a simple electronics failure).
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Serviceability was one of the reasons I chose a Roamer battery for my new van.
 
Not on the same plane, but after 3 days (effectively) the scooter lithium battery is still showing as full on the LED bar, so I've left them alone, I'll let it dip into the yellow section then swap the battery over to a full one and give it a charge, the scooter is outside in the cars boot overnight.
 
Mine lived in the back of the car and the battery inside the house.

However the longest trip with the furthest to walk and left the battery at home..

Now the whole lot is left of home now and the battery gets checked and topped up every 3 months
Or the day before I need to use it.
 
I charge once a month as advised when not in use, mine has a crap design where you can't get the battery out when it folded up :rolleyes: :rolleyes:
 
Mine is easy to remove to charge or leave it on the scooter to charge.

Well was mine just passed it on to someone ..

IMG_0750.jpegIMG_0751.jpeg
 
That was what I was looking for for the car Fred, mine is far too big and hurts my back but no other choice.
 
I have always disregarded this 80% 20% stuff but its easier to let folks think what they want than keep repeating stuff lol

When I bought my Lifepo4 both the manufacturers and Will stated its okay to use 100% - 0% so that's what I have done. Well not strictly, I take 20% as an action point knowing I haven't got much left so for some charging.
 
Mine seem to be fully charged since I fitted them the Victron app shows a few things about them but as far as I know with the solar nothing changed even when we used as much as we could use all lights awning light tv and sound bar fridge water pump .
Nothing seems to have used anything we could see at the time. So an 80. And 20 whatever never bothered us .

I just assume the victron b2 b controls it all no idea myself .
After it was wired with full instructions from member wildebus nothing seems to have changed …
 
wildebus said:
I have always said that this idea of only charging your Lithium Batteries to 80% and then only Discharging to 20% is a load of Balony. It is often stated as the way to best look after your Lithium (LiFePO4) Batteries, but really is a nonsense.

Just came across this Video posted yesterday by Will Prowse, who a lot of people regard as THE god of Lithium and Solar and it is good to see he is dispelling this myth. Maybe more people will believe him and use the blooming batteries they bought properly and fully!

I am starting the Video at the point he discusses about charging and discharging levels .... Also watch all to the end!

Remember - Use that Battery!
View attachment 74645
Click to expand...
Good video David
 
wildebus said:
I have always said that this idea of only charging your Lithium Batteries to 80% and then only Discharging to 20% is a load of Balony. It is often stated as the way to best look after your Lithium (LiFePO4) Batteries, but really is a nonsense.

Just came across this Video posted yesterday by Will Prowse, who a lot of people regard as THE god of Lithium and Solar and it is good to see he is dispelling this myth. Maybe more people will believe him and use the blooming batteries they bought properly and fully!

I am starting the Video at the point he discusses about charging and discharging levels .... Also watch all to the end!

Remember - Use that Battery!
View attachment 74645
Click to expand...
 
The only thing that I didn't see mentioned in the video was do not charge a LFP battery with its temperature is below 0degC. This is usually prevented by one of the BMS functions. It will also explain why a cold soaked MH will often not charge until the battery has warmed up. If changing to LFP batteries make sure that they are mounted in a heated part of the vehicle. I have a heater mat under mine so that the battery can keep itself warm and accept charge in cold environments. Be aware that this should only be used if you are not leaving the battery uncharged for long periods in cold temperatures.
I guess Will Prowse doesn't have the cold temperature problem in Vegas so probably why he didn't mention it.
 
So true. We picked the van up out of storage, and batteries were not holding charge. Phil kindly told me that they needed to go onto a hookup to recharge fully. That sorted them. The video explains that this rebalences. We do this everything now after a long storage.
 
Cold LiFePO4 batteries need time to warm up before being charged, it doesn’t happen instantly the cells need to be warmed right through. The BMS should protect them but some of the cheaper ones may not have temperature sensors in the centre of the battery and some cheap batteries with heaters have been shown to restart charging when parts of the cells are still too cold.
 
Chasn said:
The only thing that I didn't see mentioned in the video was do not charge a LFP battery with its temperature is below 0degC. This is usually prevented by one of the BMS functions. It will also explain why a cold soaked MH will often not charge until the battery has warmed up. If changing to LFP batteries make sure that they are mounted in a heated part of the vehicle. I have a heater mat under mine so that the battery can keep itself warm and accept charge in cold environments. Be aware that this should only be used if you are not leaving the battery uncharged for long periods in cold temperatures.
I guess Will Prowse doesn't have the cold temperature problem in Vegas so probably why he didn't mention it.
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Vegas in winter can go lower overnight than many places in the UK :)

I don't think the cold charging discussion was in scope for the video topic. If you watch other videos of his, he is fairly obsessive on the topic in fact.

The best option really is not sitting a battery on a heat mat but to have a battery with internal heater as part of the design AND a BMS that works in conjunction with it and directs power accordingly. That way you don't have to mess around with chargers with temperature sensor control and cutoffs... Just let the battery take care of it (but low temp charging is a whole different topic to the one discussed on the video)
 
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Of course if you are discharging the battery it will start to warm up as well. Temperature hasn't so far been a problem for me with my dumb battery set up but they are inside and don't hit zero or below very often.
I had to put the backup diesel heater on for a few hours on top of Cairngorms in January this year when my main heater packed up overnight. Was still up to temperature to take charge by the time I had eaten, walked dogs, done morning stuff and tacked down ready to move though.

You can buy lifepo4 battery now that will take charge below 0 degrees, don't remember how low but in negative double figures. May have been one of Will Drowse videos I saw them earlier this year. Not cheap though but I think they are designed for specific uses rather than Fred and Mabel in their camper :)
 
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