I would not push a BMS to its full rating for to long. A max 70% load for long periods are plenty. The mosfets inside can get very hot, and most bms'es are set stupidly high as 100-110C for mosfet protection. I change all my settings and mosfets set at 80C. If mosfets fail, they will fail closed, meaning all the amps are free to flow, close to short circuit current. In that instance, you will need a high rupture over current device like classT or NH or a DC breaker to open- extinguish a 7-8ka arc.
Upgrading to lithium advice please.
- Thread starter 180Sunseeker
- Start date
Barrie we are wise to the weather differences in Spain....that's why, although our apartment is in Murcia we Spend the summer mainly in Galicia...half the Murcian temperature...
However we generally leave mid September as the seasons change and instability takes over...Now we are in Aragon Bajo...it's clear blue sky and 23^c...
I don't run my 2,000 watt inverter at full power, normally no more than 1,500 watts about 145amps so about 75% but when I first had it I did once push it just to see.
- Dec 22, 2018
- 341
- 279
- Funster No
- 57,664
- MH
- Hymer Classic B584
- Exp
- Since 2019
You'll note I said 'There is no such thing as a drop in lithium without risk of damage or limiting the new battery'. I meant damage to the alternator as well as the battery and/or limiting the capacity and life of the battery. There's no contradiction there.
I assume you mean this site? Helps if you link to who you're talking about.
Lithium Pros | Lithium-ion Batteries
Lithium Pros is a group of enthusiasts who are focused on bringing the highest performance, ultra lightweight lithium-ion batteries to the marine, racing, EV, fleet, and specialty markets.
lithiumpros.com
I'm in Australia, but travel in Europe, so I know the markets in Australia, UK and some of Europe (but not so much the US). LiFePO4 (let's just use lithium) is the same worldwide though.
I've bought cheap and expensive 100Ah batteries and DIY built a 626Ah/ 250 Amp one. Each country has it's own lithium battery 'manufacturers' (actually assemblers). In the early days they could get away with charging these sort of prices as components prices (particularly the cells) were high. Some still do keep those charges high as long as people buy them. That's called 'milking the early adopters and naive'. Or 'good business'. (BTW, I'm not suggesting a cheap battery is the same as a quality battery, just that the price difference isn't justified)
At US$928 that's an extremely expensive battery. That's how they can afford to offer a 7 year warranty (I'll exclude the BS 10 year thing). Warranty conditions exclude incorrect charging, so I wonder if you did use that AGM spec charger if they'd cover it (you'd have to think so as they suggest its ok).
Regardless, the battery won't explode in your face, or burn your van down (unless your alternator sets fire to your engine bay) if you don't use Lithium chargers, but it wont last as long or give it's best. So people that say they 'did a drop in and it's fine' are ignorant of how much more fine it would be if they had the correct chargers. Or they haven't yet fried their alternator.
Last edited:
- Dec 22, 2018
- 341
- 279
- Funster No
- 57,664
- MH
- Hymer Classic B584
- Exp
- Since 2019
Oh sod, ran out of editing time. I wanted to change the post above to this:
I assume you mean this site? Helps if you link to who you're talking about.
Just found the UK one you mean:
www.lithiumpro.co.uk
I'm in Australia, but travel in Europe, so I know the markets in Australia, UK and some of Europe. LiFePO4 (let's just use lithium) is the same worldwide though. Just priced differently.
I've bought cheap and expensive 100Ah batteries and DIY built a 626Ah/ 250 Amp one. Each country has it's own lithium battery 'manufacturers' (actually assemblers). In the early days they could get away with charging high prices as components prices (particularly the cells) were high. Some still do keep those charges high as long as people buy them. That's called 'milking the early adopters and naive'. Or 'good business'. (BTW, I'm not suggesting a cheap battery is the same as a quality battery, just that the price difference isn't justified).
The battery won't explode in your face, or burn your van down (unless your alternator sets fire to your engine bay) if you don't use Lithium chargers, but it wont last as long or give it's best. So people that say they 'did a drop in and it's fine' are ignorant of how much more fine (and safe) it would be if they had the correct chargers. Or they haven't yet fried their alternator.
I'm just a mug punter, self taught DIY'er. There are people on here that know more than me. Problem is when you get people that know a lot, then they're often in the biz and some are old dogs that can't learn new tricks, or might have questionable ethics (i.e. might push their preference or product, even if it's not the best thing for you). But then you get a person like me that knows a bit and might only push the few options they've tried.
LiFePO4 cells generally can discharge at 1C (i.e. 100 Amps for a 100Ah cell). If you push them higher than that you'll limit their life. They are best used between 20 & 80% capacity. Again if you push above and below that you'll limit their life. By 'life' I mean the number of cycles. A cycle is generally accepted as being going from 80% to 20% and back to 80%. This company is suggesting doing both those things. As a couple of people have mentioned their claims for what you can run from their battery (I'm looking at the 105Ah one) don't add up. A 2000 watt inverter from a 105Ah battery is just a bad idea if not even impossible. That might run things like say, an air fryer, which you might have on for 30 minutes. Even if it could run it, and for that long, I very much doubt it'll get 1000's of cycles.
I suspect they're counting on people not using a battery to its full capability. I mean no-one (or very few people) is going to use a battery right from 80% down to 20% at full Amp capability day after day.[/URL]
You'll note I said 'There is no such thing as a drop in lithium without risk of damage or limiting the new battery'. I meant possible damage to the alternator and/or the battery and/or limiting the capacity and lifetime of the battery. Not 'it will', but 'it could'. A risk, not a certainty. There's no contradiction there.
I assume you mean this site? Helps if you link to who you're talking about.
Just found the UK one you mean:
LithiumPro Energy – Advanced Lithium Batteries for Motorhomes, Campervans and boats and Boats
Lithium leisure Batteries. Intelligent batteries for caravans motorhomes, campervans caravans and boats
www.lithiumpro.co.uk
I'm in Australia, but travel in Europe, so I know the markets in Australia, UK and some of Europe. LiFePO4 (let's just use lithium) is the same worldwide though. Just priced differently.
I've bought cheap and expensive 100Ah batteries and DIY built a 626Ah/ 250 Amp one. Each country has it's own lithium battery 'manufacturers' (actually assemblers). In the early days they could get away with charging high prices as components prices (particularly the cells) were high. Some still do keep those charges high as long as people buy them. That's called 'milking the early adopters and naive'. Or 'good business'. (BTW, I'm not suggesting a cheap battery is the same as a quality battery, just that the price difference isn't justified).
The battery won't explode in your face, or burn your van down (unless your alternator sets fire to your engine bay) if you don't use Lithium chargers, but it wont last as long or give it's best. So people that say they 'did a drop in and it's fine' are ignorant of how much more fine (and safe) it would be if they had the correct chargers. Or they haven't yet fried their alternator.
I'm just a mug punter, self taught DIY'er. There are people on here that know more than me. Problem is when you get people that know a lot, then they're often in the biz and some are old dogs that can't learn new tricks, or might have questionable ethics (i.e. might push their preference or product, even if it's not the best thing for you). But then you get a person like me that knows a bit and might only push the few options they've tried.
LiFePO4 cells generally can discharge at 1C (i.e. 100 Amps for a 100Ah cell). If you push them higher than that you'll limit their life. They are best used between 20 & 80% capacity. Again if you push above and below that you'll limit their life. By 'life' I mean the number of cycles. A cycle is generally accepted as being going from 80% to 20% and back to 80%. This company is suggesting doing both those things. As a couple of people have mentioned their claims for what you can run from their battery (I'm looking at the 105Ah one) don't add up. A 2000 watt inverter from a 105Ah battery is just a bad idea if not even impossible. That might run things like say, an air fryer, which you might have on for 30 minutes. Even if it could run it, and for that long, I very much doubt it'll get 1000's of cycles.
I suspect they're counting on people not using a battery to its full capability. I mean no-one (or very few people) is going to use a battery right from 80% down to 20% at full Amp capability day after day.[/URL]
Subscribers do not see these advertisements
- Dec 22, 2018
- 341
- 279
- Funster No
- 57,664
- MH
- Hymer Classic B584
- Exp
- Since 2019
Looking at the LithiumPro range they only have small ones (100-175Ah), a 280Ah seatbase, then one big one of 460Ah (which is £200 more and lower spec than Roamer or Fogstar). Roamer and particularly Fogstar have a better range (better spec and cheaper too). If I were buying again in the UK I'd be looking at Fogstar as they have their cheap ones (Drift Eco) that compete with the likes of EcoWorthy and the decent range and capacity Drift and Drift Pro. They also tell us what's inside. A brand name BMS and Eve cells.
BTW they all claim 'Grade A' cells. That's just a BS marketing term the Chinese cell market use that means nothing. Cells are either tested & passed for use in EV's or home battery storage - the rest are sold off for any other use, bought in bulk by Chinese resellers who randomly slap labels like Grade A on them. It means nothing. It's basically a little kid running alongside a GI saying 'Hey Johnny, me sell you tip top, number one, Grade A cell mister'.
Also look at these ones (both their own and the Fogstar they have) 10% off for us.
BTW they all claim 'Grade A' cells. That's just a BS marketing term the Chinese cell market use that means nothing. Cells are either tested & passed for use in EV's or home battery storage - the rest are sold off for any other use, bought in bulk by Chinese resellers who randomly slap labels like Grade A on them. It means nothing. It's basically a little kid running alongside a GI saying 'Hey Johnny, me sell you tip top, number one, Grade A cell mister'.
Also look at these ones (both their own and the Fogstar they have) 10% off for us.
I have said this before:
BMS can NOT and should not do the chargers job, the bms is a safety disconnect, and the charger is the normal everyday/ cycle disconnect. The charger terminates and disconnects BEFORE the safety device parameters are reached ( BMS values).
In your consumer unit you have mcb's that can be used to swith/ isolate a circuit. You don't use that for normal operation, you use a switch for everyday use.
For rate of discharge: its all in the data even on fogstars site, the continuous charge /discharge is 0.5C for 2000 cycles, 1C is max but for short or bursts of power.
BMS can NOT and should not do the chargers job, the bms is a safety disconnect, and the charger is the normal everyday/ cycle disconnect. The charger terminates and disconnects BEFORE the safety device parameters are reached ( BMS values).
In your consumer unit you have mcb's that can be used to swith/ isolate a circuit. You don't use that for normal operation, you use a switch for everyday use.
For rate of discharge: its all in the data even on fogstars site, the continuous charge /discharge is 0.5C for 2000 cycles, 1C is max but for short or bursts of power.
- Dec 22, 2018
- 341
- 279
- Funster No
- 57,664
- MH
- Hymer Classic B584
- Exp
- Since 2019
Yes (as Raul says), 0.5C discharge is the 'normal' continuous, 1C is generally considered a maximum continuous (but surely with a reduction in cycle life. Eve say 3500 cycles) and with very short times over this. Of course, the more you push them, the shorter their life will be.
You can see in this Eve 304Ah cell data sheet - items 4 & 5. These are the cells I used for my DIY battery and what are in all the batteries we're talking about. However now they're selling cells (by the sea shore) up to 330Ah. Slightly more capacity, but the charge & discharge rates will be the same.
So there are no magic Eve cells that can be pushed further than this - without a reduction in cycle count (overall battery lifetime). At 1.5C (what LithiumPro are saying) they'd have to be down in the 1500-2000 cycle area. I'm guessing they know most people wont actually push them that much although if they do try to run a 2000 watt inverter off a 100Ah battery I'd be interested to see just how short a life the battery has.
I wonder if anyone has actually tested to see if these cycle count claims are legitimate (for any batteries)? Some dodgy ebay type sellers are even claiming 15,000 cycles.
You can see in this Eve 304Ah cell data sheet - items 4 & 5. These are the cells I used for my DIY battery and what are in all the batteries we're talking about. However now they're selling cells (by the sea shore) up to 330Ah. Slightly more capacity, but the charge & discharge rates will be the same.
So there are no magic Eve cells that can be pushed further than this - without a reduction in cycle count (overall battery lifetime). At 1.5C (what LithiumPro are saying) they'd have to be down in the 1500-2000 cycle area. I'm guessing they know most people wont actually push them that much although if they do try to run a 2000 watt inverter off a 100Ah battery I'd be interested to see just how short a life the battery has.
I wonder if anyone has actually tested to see if these cycle count claims are legitimate (for any batteries)? Some dodgy ebay type sellers are even claiming 15,000 cycles.
Decide on size of lifepo4 battery you want then personally check the charging specifications to see if it matches your current chargers.
Too many retailers / installers fitting incompatible lifepo4 batteries claiming they are designed as drop in replacements.
Check your existing wiring size and fuse ratings.
Personally check mounting specifications if going with new chargers again supposed reliable professionals installing victron dcdc, mppt and ip22 mains chargers flat or in top lockers with no airflow against manufacturer's specs.
Seriously trust no one, do your research.
Too many retailers / installers fitting incompatible lifepo4 batteries claiming they are designed as drop in replacements.
Check your existing wiring size and fuse ratings.
Personally check mounting specifications if going with new chargers again supposed reliable professionals installing victron dcdc, mppt and ip22 mains chargers flat or in top lockers with no airflow against manufacturer's specs.
Seriously trust no one, do your research.
Join us or log in to post a reply.
To join in you must be a member of MotorhomeFun
Join MotorhomeFun
Join us, it quick and easy!
Log in
Already a member? Log in here.