Which sized lesuire battery?

[spruce]

It's interesting that you say this, off the subject a little I purchased a new Victron blue smart charger I read from reviews that it was charging batteries really fast, the first time I used it my battery after a full days work charged battery in under 1hr, then since then it's taken hours to charge,

Up until yesterday, I had issues with the app so I was leaving the battery charger on all night but as of yesterday I was getting the correct data it's taking 8hrs 50 mins, my old Numax charger used to be done it about 3hrs.

I don't understand the difference in time, tbh. In the old days, if a battery clamp on the charger cable didn't make a proper connection at the battery terminal, the charger showed a premature green fully charged led.

The thing is that the resistance inside the lead acid battery is what determines charge rate. You can put a 100amp charger onto the battery, but it won't change the rate of charge the battery will accept. The fuller the charge in the battery, the higher the resistance and the lower the rate of recharge.

 

[spruce]

Just so everyone is aware Fogstar are now selling 'budget' lithium leisure batteries under their brand 'Drift ECO' these don't have battery heaters or bluetooth to the bms. I think they are mainly designed for motorhomes/campervans probably not for chilly vans .
Fogstar are fast becoming the premium brand for LiFePO4 batteries among motorhomes/campervan users. They do have a very good reputation. The problem with budget brands from the likes of Amazon are you have no idea what bms (Battery Management System) they are using. Some claim to have low temp cut offs to prevent charging at low temps when some youtubers have tested them there is no low temp cut offs - so you could be damaging the cells if you attempt to charge at low temps. Similarly the cell balancing, max charge discharge etc might not be managed correctly.

I will be looking very closely at the Fogstar Drift Eco when my van leisure battery fails as I'm not keen on the 'smart split charge relay' that I currently have so might disconnect it and just buy a lithium and lithium charger. So although the purchase cost would probably be double a decent lead acid it should last 6 to 10 years!

The trouble with no heating blanket is that the battery doesn't get charged at temps below 5 degrees. If your van's temp is below that, then you could be in trouble.
I have a full steel factory bulkhead installed, so any heat in the driver's cabin doesn't affect the cargo area much. So the cargo area is always cold.
Even when using the diesel heater, not much heat is radiated into the cargo area as I have a towel over it as a bit of insulation.

I agree that your best route is to rely on mains charging. Fogstar recommended we let the battery charge drop to 30% before recharging. They didn't specially answer the why question I asked, though they did say it was good for the battery's chemistry. However, I also feel that as the BMS counts the battery cycles, having an extended charge depletion helps with this figure.
I fitted this battery last December and have completed 12 cycles. Hopefully, if this means anything and doing the maths, the battery should still be OK long after I have passed away.

 

[ched999uk]

The trouble with no heating blanket is that the battery doesn't get charged at temps below 5 degrees. If your van's temp is below that, then you could be in trouble.
I have a full steel factory bulkhead installed, so any heat in the driver's cabin doesn't affect the cargo area much. So the cargo area is always cold.
Even when using the diesel heater, not much heat is radiated into the cargo area as I have a towel over it as a bit of insulation.

I agree that your best route is to rely on mains charging. Fogstar recommended we let the battery charge drop to 30% before recharging. They didn't specially answer the why question I asked, though they did say it was good for the battery's chemistry. However, I also feel that as the BMS counts the battery cycles, having an extended charge depletion helps with this figure.
I fitted this battery last December and have completed 12 cycles. Hopefully, if this means anything and doing the maths, the battery should still be OK long after I have passed away.

I tend to put an oil filled rad in the back if the temps are dropping below about 3 so I would just use that a little more. The rear of my van is insulated which seems to work as the ice doesn't melt on the roof with the rad on although that could just be that it can't raise the temp enough
To be honest I might just push the boat out a little and get the non ECO version to get the battery heater and the bluetooth stats as I do love stats and apps. I have a Victron solar mppt controller and Home Assistant on my solar at home and I do like looking at the graphs .

 

[spruce]

Seeing as this post is resurrected then. I’ve still been confused with most of what read. If I wanted a battery that I’d happily charge every night to cope with a one man system (no B2B or anything) working a 7 hour day (including travel) a 100a or over Numax would be a good buy?
Would an electric reel make a difference?

As per @Iron Giant .

The thing with a hose reel is the initial power surge at the moment before the motor of the hose reel starts turning. It is basically a direct short, albeit for milliseconds. A standard leisure battery doesn't like this.

Xline advertise their electric hose reel with a powerful 280 watt motor. That's 23 amps. That's a high current draw for a standard leisure battery. Hence the reason why we suggest using a combo battery that has a cold cranking amp capability.

 

[spruce]

I tend to put an oil filled rad in the back if the temps are dropping below about 3 so I would just use that a little more. The rear of my van is insulated which seems to work as the ice doesn't melt on the roof with the rad on although that could just be that it can't raise the temp enough
To be honest I might just push the boat out a little and get the non ECO version to get the battery heater and the bluetooth stats as I do love stats and apps. I have a Victron solar mppt controller and Home Assistant on my solar at home and I do like looking at the graphs .

So do I. The Germans were very good at interpreting graphs and data, so I learnt a bit from them when working for Bosch.

 

[spruce]

I will update this DIY post after this winter with added lithium experience. I felt that the battery was too new last winter for me to draw any conclusions.
This was totally new technology for me. I couldn't believe how a small, lightweight battery could supply our current needs better than the lead acid batteries we have used for years.

Split Charge Relay

Split Charge Relay. Most window cleaners who use the Water Fed Pole with a van mounted tank will, sooner or later, question whether they need to add an auxiliary charging method for their leisure battery that’s driven from the vehicle’s alternator or not. A Split Charge Relay (SCR) is now a...

windowcleaningforums.co.uk

 

[Iron Giant]

I don't understand the difference in time, tbh. In the old days, if a battery clamp on the charger cable didn't make a proper connection at the battery terminal, the charger showed a premature green fully charged led.

The thing is that the resistance inside the lead acid battery is what determines charge rate. You can put a 100amp charger onto the battery, but it won't change the rate of charge the battery will accept. The fuller the charge in the battery, the higher the resistance and the lower the rate of recharge.

Thanks for this I have a solid connection to the battery with the threaded terminals as I have the connections solid with some M8 wing nuts,

I did initially think that before I had bought the wing nuts and just had the the connectors were just placed over the terminals it might not have been solid connection, although the battery did show the correct voltage on my controller and lasted a full day.

 

[spruce]

It seems to indicate that the battery didn't get a full charge but there was ample left in the battery to last the day.
The residue voltage could have taken longer to dissipate, giving a false reading.

I don't know.

 

[Iron Giant]

It seems to indicate that the battery didn't get a full charge but there was ample left in the battery to last the day.
The residue voltage could have taken longer to dissipate, giving a false reading.

I don't know.

I have just checked my dates and it's helped me jog my failing memory, I only did half a day as it was a Friday and then the charger was left connected until Sunday as we weren't at home I think it was on float when we got back, I skived off on the Monday and purchased the wing nuts

No idea what had been going on with the app because until this Wednesday it was stating that only one charging cycle had been completed which wasn't the case at all, then all of a sudden10 charge cycles were completed, now the app is working as it should I'll monitor the charging cycle data and adjust my smart plug settings accordingly to ensure it is switched off.

 

[Iron Giant]

I have a Victron solar mppt controller and Home Assistant on my solar at home and I do like looking at the graphs .

I can send you some Victron graph data as I ain't got a clue what they mean

 

[spruce]

An update for any one interested.

I checked my lithium phosphate battery's app this morning before leaving the house. It was showing that I had 72% of charge left in my 100amp battery.
Today we did 30 miles and used the battery during our working day to run the pumps.
When I got home this afternoon, I again checked the app. My battery was fully charged. I then switched my b2b charger off as I don't want to over charge the battery tomorrow.

This is a totally new experience for me. I have always had to bench charge my lead acid leisure batteries every evening.

 

[Pjj]

An update for any one interested.

I checked my lithium phosphate battery's app this morning before leaving the house. It was showing that I had 72% of charge left in my 105amp battery.
Today we did 30 miles and used the battery during our working day to run the pumps.
When I got home this afternoon, I again checked the app. My battery was fully charged. I then switched my b2b charger off as I don't want to over charge the battery tomorrow.

This is a totally new experience for me. I have always had to bench charge my lead acid leisure batteries every evening.

Ime finding that the charge time for the lithium battery is much less than the AGM batteries I had before usually it’s fully charged in two hours or less after running everything for 8 hours

 

[CMcB]

For those that use lithium batteries- do you use or see the need for any extra fire safety/protection when you use one, or do you rely on the protections built into the battery by the manufacturer? I think the next battery I get will be a lithium one, but that was one thing I was concerned about.

 

[ched999uk]

For those that use lithium batteries- do you use or see the need for any extra fire safety/protection when you use one, or do you rely on the protections built into the battery by the manufacturer? I think the next battery I get will be a lithium one, but that was one thing I was concerned about.

They are normally LiFePO4 ie Lithium phosphate which is a lot more stable than the lithium ion batteries in some mobiles, scooters, bikes etc. The LiFePO4 are much safer but if they do catch fire they are still as dangerous.
The problem with changing to LiFePO4 is that you need chargers that can charge these batteries correctly, be that just a home charger or a b2b and a home charger. Sometimes people try and cut corners and use an unsuitable charger and that can cause issues.

 

[spruce]

For those that use lithium batteries- do you use or see the need for any extra fire safety/protection when you use one, or do you rely on the protections built into the battery by the manufacturer? I think the next battery I get will be a lithium one, but that was one thing I was concerned about.

I shared you concerns to begin with.

@ched999uk has put this into perspective with his reply.

As I've said, gone are the days when I just left the smart leisure battery connected up to my leisure battery all weekend.
Yesterday my battery was fully charged, so I switched my b2b charger off.
I will let the charge in the battery drop into about 60% of charge and then switch the b2b charger on.

A good supplier will tell you not to let the battery's bms be the last line of defence. When the battery is nearly fully charged, switch the charger off. Overcharging a lithium battery is asking for trouble.

I love this not having to connect the battery charger up every night. However, I'm having the same issue as a lot of tradesmen are having with their vans that don't do much mileage. The starter battery needs charging once every couple of weeks. There is a builder working a couple of doors down and he has a solar panel on his dash board. A plumber has the same van as I do except a year younger and he had the charger on his van the other day.

The litmus test of this battery will be over winter when we start using the diesel heater. I will have to bench charge this battery every now and again.

The only thing with lithium is that the batteries won't accept a charge in freezing weather. The battery I have has an internal heating blanket. The internal battery's bms will direct 10 amps of charging power to heat the blanket which warms the battery. Once the battery's internal temperature reaches 5 degrees, the battery will start charging.

So last winter when I thought the battery was accepting a 10 amp charge, it wasn't. It was the heating blanket on.
It's the same as EV's. In the freezing American weather last winter, quick charging a Telsa was a night mare. The first part of the charge cycle is to warm the battery up.

You don't need a b2b charger, but you do need a special lithium battery charger. I brought one from Fogstar, the supplier of my battery. I could just use that charger every 3 or 4 days to recharge the battery.

 

[sleepyfolk]

I shared you concerns to begin with.

@ched999uk has put this into perspective with his reply.

As I've said, gone are the days when I just left the smart leisure battery connected up to my leisure battery all weekend.
Yesterday my battery was fully charged, so I switched my b2b charger off.
I will let the charge in the battery drop into about 60% of charge and then switch the b2b charger on.

A good supplier will tell you not to let the battery's bms be the last line of defence. When the battery is nearly fully charged, switch the charger off. Overcharging a lithium battery is asking for trouble.

I love this not having to connect the battery charger up every night. However, I'm having the same issue as a lot of tradesmen are having with their vans that don't do much mileage. The starter battery needs charging once every couple of weeks. There is a builder working a couple of doors down and he has a solar panel on his dash board. A plumber has the same van as I do except a year younger and he had the charger on his van the other day.

The litmus test of this battery will be over winter when we start using the diesel heater. I will have to bench charge this battery every now and again.

The only thing with lithium is that the batteries won't accept a charge in freezing weather. The battery I have has an internal heating blanket. The internal battery's bms will direct 10 amps of charging power to heat the blanket which warms the battery. Once the battery's internal temperature reaches 5 degrees, the battery will start charging.

So last winter when I thought the battery was accepting a 10 amp charge, it wasn't. It was the heating blanket on.
It's the same as EV's. In the freezing American weather last winter, quick charging a Telsa was a night mare. The first part of the charge cycle is to warm the battery up.

You don't need a b2b charger, but you do need a special lithium battery charger. I brought one from Fogstar, the supplier of my battery. I could just use that charger every 3 or 4 days to recharge the battery.

Why is it that a b2b would overcharge the battery, if it has a lithium charging profile and is supposed to be smart I don’t see why you’d need to turn it off ?

 

[spruce]

Why is it that a b2b would overcharge the battery, if it has a lithium charging profile and is supposed to be smart I don’t see why you’d need to turn it off ?

That's s good question.

The instructions for use say that once the battery is fully charged to switch the charger off.
With our smart charger and leisure battery, the charger would identify when the battery was fully charged, and switch the charger onto a very small trickle charge, referred to as float mode. We are told a lead acid battery looses around 5% of it's state of charge every week under ideal conditions.

Fogstar say that the reason for this instruction is that the bms shouldn't be the last line of defence. Because of the battery's composition, it doesn't loose charge at the same rate a lead acid battery does.

They also state that excess charge can only be dissipated as heat. We don't want that. Remember the mobile phone saga a few years back.

Maybe my Sterling b2b charger will put itself into float mode once a certain point is reached. But I'm not going to test that to see if it's true.

The thing is that not all the experts in the lithium field agree on how to charge and maintain a lithium battery. For example, one YouTube poster says it should be charged at 14.2v and another 14.4v. they then say float should be set at 13.2v and another days 13.4v. then others say it should never be put into float mode in the first place.

My Sterling charger output is set at a charge rate of 13.8v by default. I can adjust that higher manually, but it seems to charge just fine the way it is. I have never pushed it further to see if it does go into float mode.

Nobody seems to answer the question of how the charger recognises it needs to go into float mode either.

Fogstar also recommend that the battery isn't kept in a full state of charge. Rather they recommend the charge be left to drop to around 30% before recharging.

All I'm doing is trying to work within the guide lines. This is all new technology for me. The batteries don't work the same way as our old lead acid batteries did.

 

[Iron Giant]

That's s good question.

The instructions for use say that once the battery is fully charged to switch the charger off.
With our smart charger and leisure battery, the charger would identify when the battery was fully charged, and switch the charger onto a very small trickle charge, referred to as float mode. We are told a lead acid battery looses around 5% of it's state of charge every week under ideal conditions.

Fogstar say that the reason for this instruction is that the bms shouldn't be the last line of defence. Because of the battery's composition, it doesn't loose charge at the same rate a lead acid battery does.

They also state that excess charge can only be dissipated as heat. We don't want that. Remember the mobile phone saga a few years back.

Maybe my Sterling b2b charger will put itself into float mode once a certain point is reached. But I'm not going to test that to see if it's true.

The thing is that not all the experts in the lithium field agree on how to charge and maintain a lithium battery. For example, one YouTube poster says it should be charged at 14.2v and another 14.4v. they then say float should be set at 13.2v and another days 13.4v. then others say it should never be put into float mode in the first place.

My Sterling charger output is set a charge rate of 13.8v. I can adjust that higher manually, but it seems to charge just fine the way it is. I have never pushed it further to see if it does go into float mode.

Nobody seems to answer the question of how the charger recognises it needs to go into float mode either.

Fogstar also recommend that the battery isn't kept in a full state of charge. Rather they recommend the charge be left to drop to around 30% before recharging.

All I'm doing is trying to work within the guide lines. This is all new technology for me. The batteries don't work the same way as our old lead acid batteries did.

If your B2B is plugged into the mains or an extension lead can't you just check the timings of your Victron data and set a schedule with a smart plug app?

this is what I do with my lead acid battery I allow an extra 10 minutes or so now this may need to be tweaked as we go into the colder months

 

[PC]

Sounds like these Lithium are more trouble than they are worth. No?
All seems a bit of the ‘over-thinking things syndrome’ to me.
Can’t see what’s wrong with a half decent standard leisure battery.
Maybe someone will educate me as to why I should change. Always looking to improve

 

[spruce]

If your B2B is plugged into the mains or an extension lead can't you just check the timings of your Victron data and set a schedule with a smart plug app?

this is what I do with my lead acid battery I allow an extra 10 minutes or so now this may need to be tweaked as we go into the colder months

The b2b charger I have is also referred to as a dc to dc charger which is alternator powered.

 

[spruce]

Sounds like these Lithium are more trouble than they are worth. No?
All seems a bit of the ‘over-thinking things syndrome’ to me.
Can’t see what’s wrong with a half decent standard leisure battery.
Maybe someone will educate me as to why I should change. Always looking to improve

If it's working for you, then stay with what you have.
I don't have to plug a 230v charger into my van every night to top up my battery any longer, so for me that's a saving.

I decided to go lithium due to my diesel heater. The trouble with lead acid batteries is that they lose capacity without you knowing it. Suddenly you find the diesel heater has switched off due to low voltage. That doesn't do the heater any good.
So far, even with the battery at 60% charge, it still reads 13.1v. If I switch the diesel heater on, that voltage doesn't flinch.

I don't know how the battery will perform down the line in a few years time. I could well not be around to report that if the battery lasts as long and performs as they predict. My guess is that @Pjj will find out before me as he demands much more from his battery than I do and he is also much younger than I am.