Welcome to the UK Window Cleaning Forums

Starting or own a window cleaning business? We're a network of window cleaners sharing advice, tips & experience. Rounds for sale & more. Join us today!

Which sized lesuire battery?

WCF

Help Support WCF:

The other thing about lithium @PC is that it charges at a faster rate than lead acid batteries do.
My leisure battery would only accept a charge of 4 or 5 amps when it was 90% charged. This lithium battery will accept a charge of 30 amps even when nearing fully charged.

A 100 amp lithium battery will accept a charge of 100 amps, but the battery won't last long if done continually. I doubt the van's alternator would last long either But it can be charged at 50 amps without issue, although the recommendation is 30 amps for my 105 amp battery. Hence the reason why I have set the b2b charger's output at 30 amps rather than the default setting of 60 amps.

Victron have released a 50 amp unit recently I understand. The Australians are raving about it. I haven't seen them advertised here but then I haven't been looking.
 
Last edited:
Lithium ion has had a bad press of late. This has affected my thinking as well. So I'm treading cautiously with my dealings with this battery.

Lithium phosphate Lifepo4 is a much safer battery composition. But I believe I must err on the side of caution in these early days. @PC

Maybe I'm being too cautious, I don't know. I guess time will tell.

If anyone is worried about the safety aspect of lithium phosphate then I will always say to stick with what they have now.
 
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.
Thanks for that, yes it’s interesting - I noticed that fogstar had stated an absorption voltage of 14.2v and float voltage of 13.6v in the full manual for the 230ah battery. I do quite a few miles so I was wondering if I could get away without buying a specific mains lithium charger and it sounds like my Victron in the van might well keep up.
 
Good to know - think I’ll order the fogstar over the weekend , and some resin, and another 100m hose - that burst today 😂
The cold of winter is when things could change for me. At the moment my internal battery temperature is 12 degrees. ( It was yesterday.) So the moment my b2b charger kicks on, my battery is receiving a charge.

When the internal temperature of the battery drops below 5 degrees, the battery will not accept a charge. The bms switches the charge from my b2b charger to the internal heating blanket. So the low mileage I do will be mainly heating the battery rather than charging the battery. When I saw a charge of 10 amps going into the battery using my Victron battery monitor, I presumed the battery was being charged. It wasn't. It was the battery being warmed up before the charging process would begin.

When I bought the battery I also added a 20 amp charger to the order. I used that charger a few times last winter, but with no experience, I didn't really understand what exactly was going on. I had always put my old leisure battery on charge every night, so doing this with the new battery last winter was a normal thing for me to do.

This is why I need to experience this winter before I update my post on split charge relays on the diy section.
 
Last edited:
Good to know - think I’ll order the fogstar over the weekend , and some resin, and another 100m hose - that burst today 😂
Just so you are aware, Fogstar do 2 types of lithium battery, 1 with heating and Bluetooth and the other just a basic battery and no Bluetooth or heating element. As it will live in a van and be used all year round it might be worth paying the extra and getting the one with the heating element in. It's not only charging that lithium suffers with in the cold (you can actually damage them if you try and charge them and they are too cold) but their ability to provide power is reduced when they are cold. Although for our use that's probably not an issue it's more trying to pull lots of current that they don't like when cold, eg if used in a motorhome and people try running 2000watt inverters from them when the battery is very cold.
 
Just so you are aware, Fogstar do 2 types of lithium battery, 1 with heating and Bluetooth and the other just a basic battery and no Bluetooth or heating element. As it will live in a van and be used all year round it might be worth paying the extra and getting the one with the heating element in. It's not only charging that lithium suffers with in the cold (you can actually damage them if you try and charge them and they are too cold) but their ability to provide power is reduced when they are cold. Although for our use that's probably not an issue it's more trying to pull lots of current that they don't like when cold, eg if used in a motorhome and people try running 2000watt inverters from them when the battery is very cold.
Yes it’s the 230ah with heating I’m looking at, not that my van is cold usually - it’s insulated and heated at night which is more than I can say for the house 😂
 
Yes it’s the 230ah with heating I’m looking at, not that my van is cold usually - it’s insulated and heated at night which is more than I can say for the house 😂
My van, although nothing has ever frozen, isn't exactly warm. It's not much above 3 degrees as the diesel heater kicks on several times on a cold night.

I have threatened to carpet the roof to retain some heat, but another winter will arrive with it not done.
 
Have just fitted a 105ah fogstar drift LifePo4 battery.
Gave up on my AGM, with a diesel heater & powered reel the power requirements necessitate a larger battery, my 250ah battery weights 63kg!
LifePo4 - 10kg - go figure.
With lithium batteries coming down in price there's no need to use anything else.
If you're just running a pump, LifePo4 would last maybe two weeks!

I mostly work on my own, so for a two man setup (two powered reels etc) you may need a larger capacity battery (or use b2b charger, if you do the miles) I plug mine in at end of day, as only do 20 miles or so and dont use b2b.

Will come back in 6 months with an update, see how it wears in.
 
Have just fitted a 105ah fogstar drift LifePo4 battery.
Gave up on my AGM, with a diesel heater & powered reel the power requirements necessitate a larger battery, my 250ah battery weights 63kg!
LifePo4 - 10kg - go figure.
With lithium batteries coming down in price there's no need to use anything else.
If you're just running a pump, LifePo4 would last maybe two weeks!

I mostly work on my own, so for a two man setup (two powered reels etc) you may need a larger capacity battery (or use b2b charger, if you do the miles) I plug mine in at end of day, as only do 20 miles or so and dont use b2b.

Will come back in 6 months with an update, see how it wears in.
The more I get into this lithium battery, the more intriguing it gets.

My battery was showing 100% charged when I got home this afternoon

It was still receiving a charge of 28 amps. My b2b charger is set to a charge rate of 30 amps. Had this been my lead acid leisure battery, the charge rate would have been around 2 amps.

No wonder it took so long to fully recharge it.
 
Have just fitted a 105ah fogstar drift LifePo4 battery.
Gave up on my AGM, with a diesel heater & powered reel the power requirements necessitate a larger battery, my 250ah battery weights 63kg!
LifePo4 - 10kg - go figure.
With lithium batteries coming down in price there's no need to use anything else.
If you're just running a pump, LifePo4 would last maybe two weeks!

I mostly work on my own, so for a two man setup (two powered reels etc) you may need a larger capacity battery (or use b2b charger, if you do the miles) I plug mine in at end of day, as only do 20 miles or so and dont use b2b.

Will come back in 6 months with an update, see how it wears in.
If you download the app onto your phone, you can keep track of the battery's charge and temperature.
 
If you download the app onto your phone, you can keep track of the battery's charge and temperature.
Just wanted to thank you for the info about the Fogstar battery. Just replaced my deteriorating leisure battery with the 105ah Drift and at the same time installed the Orion XS B2B.
I used to bench charge my leisure battery, the VSR wasn't keeping up with usage as expected. However my initial run with the lithium battery I used 12% of its capacity for a medium days work (2 pumps + 2 electric reels). Based on how quickly it charged from the 30% charge it arrived with, I doubt I'll ever need to bench charge again which is a big plus for me. Another plus is it provides 13v+ all the while, meaning my pumps and reels both performed better than I had got accustomed to with an older leisure battery. Being able to turn off the terminals from the app and monitor in real time the approximate current draw is also really cool. Thanks again!
 
Last edited:
Back
Top