Newbie battery charger questions

[wallport]

OK you have all made me think - you should be in sales

I might have just bought one but for these issues.

1. The fogstar, whilst being smaller overall, is 19mm taller and I'm pretty sure won't fit in the existing battery cabinet.
2. It's out of stock until end of May and I don't think we can wait that long with effectively no lb.
3. I'm not sure if the victron ip22 12/15 is compatible - I can't find any specific mention of lifep04 (the ctek d250se does seem to be OK as far as I can tell)

Any thoughts on these issues?

BTW I'm unsure how the existing battery is anchored to the floor?

 

[TallPaul_S]

OK you have all made me think - you should be in sales .

I might have just bought one but for these issues.

1. The fogstar, whilst being smaller overall, is 19mm taller and I'm pretty sure won't fit in the existing battery cabinet.
2. It's out of stock until end of May and I don't think we can wait that long with effectively no lb.
3. I'm not sure if the victron ip22 12/15 is compatible - I can't find any specific mention of lifep04 (the ctek d250se does seem to be OK as far as I can tell)

Any thoughts on these issues?

BTW I'm unsure how the existing battery is anchored to the floor?

Victron should definitely be 100% LiFePO4 compatible.

In the settings you should see this


LiFePO4 batteries can be mounted on their side with no issues, so take that into account when checking your space.

This is your battery

L36-100 - Leisure Marine & Garden View All - Batteries

<p><strong>YBX Active Leisure and Marine</strong></p> <ul> <li>Optimised for repeated charging & discharging</li> <li>Original equipment quality & specification</li> <li>NCC Verified Class C</li> <li>Maintenance free</li> <li>Supplied charge

www.yuasa.co.uk

Length 353mm
Width 175mm
Height 190mm

As you say, you might struggle to find a 100Ah LiFePO4 that fits, ironically.

Fogstar is:
Length 260mm
Width 168mm
Height 209mm

Even on its side, it's too tall (wide).

Also it doesn't look like your battery is fixed down at all your your van, it'd normally use the slots in the base to secure it down, there might be something on there vertical sections that is keeping it in place.

Out of interest, where is the actual battery box located? That looks like a bed frame above it?

There's no reason why you couldn't just leave the top wood lid off, which would let you fit a taller battery.

 

[wallport]

Hah OK having been educated about the difference between between LiFePO4 and li-ion I was looking for specific mention of LiFePO4.

Yes, it is a RIB bed above it and there is no reason why the box couldn't have been built slightly taller. Indeed someone with some woodworking skills could make it taller.

I'm reluctant to leave the lid off due to shorting risk - something metal dropped when converting the bed or spilt drink etc but I agree there would be solutions to all of this.

I am going to talk to a local van conversion company to see if I can get a fogstar fitted and the box altered economically. If they want to charge too much I will give it a go but I'd rather get it done properly if poss. I think we can wait by just restricting journeys to sites with hookup.

As for it being fixed down, I tried to slide it and it didn't move with moderate force so I came to the conclusion it was secured somehow. I wondered if they had just glued it to the floor.

 

[TallPaul_S]

You could just get some terminal covers which would protect from shorting.

Your current battery is 23kg so you'd probably struggle to move it sideways just by pushing it, but I'd hope it's secured down!

Definitely worth getting the battery properly tested before you bite the bullet, but I doubt you'll regret going LiFePO4 - not only for the extra capacity, ability to use an inverter, but also the fogstar has an excellent BMS with Bluetooth app, no guessing about the state of charge.

 

[roadtripper]

Just to add that earlier on in the thread your battery did seem to be getting full charge cycles from the Victron. However this recent short cycling is looking more likely to be signs of a failing battery. The ability of an lead acid to take charge reduces as it ages and effectively it becomes a smaller and smaller battery, one that seems to charge very quickly and then not last very long off charge.

So I think over the time we've been looking you've had a battery that was OK but likely on the edge of it's end of life and has now tipped over that line.

I'm very much on "Team LiFePo" for leisure systems and you've got some solid advice. Just being devil's advocate you're not today putting that heavy a load on your leisure system and replacing your existing battery with a good quality deep cycle battery should be a simple change at home for not a lot of spend.

I would strongly advise though if you add anything like Solar invest in equipment that will suit LiFePo as well either way you choose. Changing a battery is relatively straightforward, changing all your chargers less so!

 

[wallport]

So I think over the time we've been looking you've had a battery that was OK but likely on the edge of it's end of life and has now tipped over that line.

That has become my interpretation but could have been wishful thinking on my part.

I'm very much on "Team LiFePo" for leisure systems and you've got some solid advice. Just being devil's advocate you're not today putting that heavy a load on your leisure system and replacing your existing battery with a good quality deep cycle battery should be a simple change at home for not a lot of spend.

Indeed swapping out existing battery like for like (or slight upgrade) would be easy DIY but I am getting a bit sick of battery nursing. Hence the points you have all made about lifepo4, once I understood it's not a big fire risk, really hammered home.

I would strongly advise though if you add anything like Solar invest in equipment that will suit LiFePo as well either way you choose. Changing a battery is relatively straightforward, changing all your chargers less so!

I am also thinking that the increased capacity could avoid us needing solar and thus I could perhaps view it as a cost saving.

 

[TallPaul_S]

Tbh if you only need 2-3 days off grid at most, then 100Ah should see you through.

Fridge would be 1Ah per hour, so 75Ah for 3 full days of use, then there's extra for diesel heater, lights, phone charging etc.

And if you do decide to get solar down the road, you want need as much as you'll only need to top up the battery, not fully replace what's being used.

 

[wallport]

Had a lengthy chat with a very helpful local fitter. He is pretty sure the battery is dead having seen the evidence.

He also sang the praises of fogstar and has convinced me to have a go at doing it myself. I'm not exactly sure what to do with the woodwork but he said I can use him as a fallback.

Seeing if I can find anyone with stock of the battery or it will be June at earliest.

 

[wallport]

Thought this thread was getting a bit long so have started a new one to cover the swap Swapping my leisure battery to LiFePO4

 

[wallport]

Back on this thread as it concerns the old battery charging. Please could you help me understand what the victron app is showing - although the battery is being deemed knackered what the app is saying should still record factually what its doing?

It's been on charge via hookup for about 6 hours and the battery monitor tells me

Here is what I see in the victron app:

So far all OK that corresponds.

Unsure if this is just a stock screen showing the stages with the current one highlighted. No timescale on the axis.

So this should be what is going on now but the voltages are both above 14v? The little popout window is saying something about what has happened since it was put on charge? I'm confused by the 30 minutes?

So this was the cycle before - this can only be relating to the previous time I put it on hookup due to the elapsed time being longer than it's been on hookup this time. So I previously thought cycles were different levels being applied as the battery charged so that you had many per hookup session but that must be wrong.

Again mentions 30mins.

I daresay I'm being stupid but I can't find any explanation of this documented so I'd be grateful for some insight. How is this information helpful? Why doesn't it tell you more?

One thing I do now understand is that when you scroll the history in landscape, it's not refreshing but just recalibrating the scale - so it may look different but it's the same! At least I worked that one out!

 

[TallPaul_S]

So that active cycle has completed - the cycle only includes bulk and absorption stages, as this is all that's required to get the battery to 100% charge.

As I mentioned before, the charger for your battery is basically missing out the bulk stage, it's going straight into absorption. It thinks the battery is over 80% charged when you put it on hookup. The absorption stage is a minimum of 30 minutes. At which point, it thinks the battery is 100% charged. I bet if there wasn't a 30m minimum it'd end the absorption stage in 5 minutes or less.

So once it's done with the absorption stage, that's the cycle complete. It then goes into float stage which is just keeping the battery at 100% with a tiny charge. If it then sees no load or activity for a while (4hrs in your case) it goes into storage mode as it thinks the battery isn't being used.

You can see this quite clearly on the BM2.


The 14v just relates to the voltage at the point the absorption stage ended. If there's no draw on the battery, the surface charge will take a good few hours to go away, so seeing 14v at the end of that stage is normal(ish) - you'd normally see about 13.5v or thereabouts. The heavy that your battery is starting at 11.9v and basically taking zero bulk charge and zero absorption charge means you can just ignore this voltage figures for the moment. 11.9v on a healthy battery would be around 50% charged so it would need to put back in 50Ah. Which it clearly isn't

 

[wallport]

Thanks for explaining that - it's not how I'd display it in an app, particularly with no documentation, but that's just me.

I don't want to get us all bogged down in discussing my failed and soon to be replaced battery anymore but it did something confusing again.

So looking at the last period before the gap. I charged it with the victron all fuses pulled. On the afternoon of the 5th I drove it (all fuses except victron pulled) to go see the conversion company - about 30 mins each way. The battery bounced back above 12v. Just wondering, does sloshing the acid about whilst driving do something maybe?

 

[TallPaul_S]

Thanks for explaining that - it's not how I'd display it in an app, particularly with no documentation, but that's just me.

I don't want to get us all bogged down in discussing my failed and soon to be replaced battery anymore but it did something confusing again.
View attachment 240678
So looking at the last period before the gap. I charged it with the victron all fuses pulled. On the afternoon of the 5th I drove it (all fuses except victron pulled) to go see the conversion company - about 30 mins each way. The battery bounced back above 12v. Just wondering, does sloshing the acid about whilst driving do something maybe?

It does, something to do with the electrolytes in the fluid surrounding the plates in the battery, which settle or separate if a battery is stored for long periods. It's all above my pay grade though!!

So it's probably helped a bit but you can see the voltage dropped back down to under 12v a few days later, so I don't think it'll fix your battery long term.

 

[roadtripper]

The reason your battery has aged and lost capacity is that sulphite has grown on the plates. This does two things, it means there is less plate area for the chemical reaction to happen on so less of the battery is "working" and also peak current will be down so any load the voltage will drop more than expected. In the extreme case that can grow and start shorting plates at which point the voltages will normally drop by about 2v and the battery will self discharge quite quickly - a 12v battery is actually made from 6 2v cells, you can see them if you peel the stickers or plastic top plate off and find the filler caps.

So by agitating the battery as it's a wet battery your stirring up the electrolyte and bringing fresh chemicals to clean areas of the plates.

You can charge a wet lead acid by simply swapping the electrolyte. At one point it was a serious consideration for electric traction as you can do it quite quickly and have large tanks of fresh electrolyte charging ready to go back into batteries.


Note this doesn't happen with AGM or GEL batteries as the electrolyte is physically held against the plates, but it probably does happen in an EFB as that has free electrolyte as well.

 

[wallport]

So, wife took the van off 2-3 hours away with no hookup over the weekend (I put back all fuses including the d250se but excluding the heater) . Here's what happened

And here's what the victron shows after I noticed the drop to below 11v on her return.


I'm fine that the battery's knackered but please can someone help me understand why the victron doesn't bulk charge it. How does the victron detect the battery state ie how is the battery 'fooling' it?

Can I be confident the victron is working as it should?

 

[TallPaul_S]

So, wife took the van off 2-3 hours away with no hookup over the weekend (I put back all fuses including the d250se but excluding the heater) . Here's what happened
View attachment 241217
And here's what the victron shows after I noticed the drop to below 11v on her return.
View attachment 241218

I'm fine that the battery's knackered but please can someone help me understand why the victron doesn't bulk charge it. How does the victron detect the battery state ie how is the battery 'fooling' it?

Can I be confident the victron is working as it should?

It's the voltage.

Here's mine when I put my starter battery on charge. It's at 12v before charging, the next line up is 13v and the one one above that is 15v.

You can see the bulk charge stage where the battery voltage starts at about
13.2v and then over a few hours, gradually goes up to 14.5v. That's the trigger to switch to absorption.

Now, yours:

Yours is going Immediately from under 11v to 14.5v. the Victron then says 'oh, it's at 14.5v, must be time to switch to the next stage'.

It's basically taking zero charge but immediately showing at 14.5v.

 

[roadtripper]

Remember that a damaged battery acts like one of a much smaller capacity, because less of the electrolyte is contact with the plates as mentioned before.

So the charge on the plates from the charger is driving the chemical reaction backwards in the electrolyte, but it can only do this in a few areas. Normally there would be much more near the plates so lots of reaction, but with only a little bit it's not long before the voltage rises in just those areas of contact and the charger changes stage.

What you see isn't unusual if you think of it as a small motorcycle battery.

 

[wallport]

Thanks for that both.

I assume there is no issue camping with it with hookup until the new battery arrives?

 

[roadtripper]

No, the battery is taking charge just not very much.

Only issue would be if the voltage starts dropping very low, then the battery may start taking all the energy from the charger and is at risk of localised overheating. That would be dropping under 10v and never reaching any charge state, and I think you are a fair way from that.