Club 80-90 Forums

crazydiamond wrote: ↑13 Apr 2025, 09:32 I am at the same point keep killing lead acid batteries and looking at LIFPo4 100ah battery and b to b setup. Whats the thoughts on a 20amp b to b for a standard cu engine output? What about a 20amp setup at about £145 from ebay I use a fold up solar panel when parked up.
Or a victron 20amp

I've got a Victron 30amp Dc to Dc charger and it really pumps the Amps in, around 27 according to the Fogstar App.

I went for the 30amp over the 18amp as apparently LIFPo4 batteries can take the higher input and from my experience it seems to be working ok.
 

totorro wrote: ↑13 Apr 2025, 19:37

Alfredo wrote: ↑13 Apr 2025, 05:20

dcworm57 wrote: ↑12 Apr 2025, 20:45
There is a lithium under the seat option from Campervan culture , they are not cheap though. Have a look on their website 

That's why I asked about the Fogstar which is the same height as the CC one.

CC lithium Dimensions:
L x W x H mm 260 x 160 x 210

 210 mm is taller than the maximum 175mm quoted by many.

The CC one is 60ah at nearly £600
Fogstar is 105ah for around £300

I don't think the 60Ah one currently on the CVC website is the one which fits under the seat. There's some information on it here - https://campervanculture.com/vw-t25-t3- ... bluetooth/ - but the product link and video have been removed.

Doesn't look like CVC sell it any more, but it seems to be this one - https://www.lithiumpro.co.uk/newshop/12 ... _yjG2Er5e6 - 189mm high and I think the top of the box is 185mm? Still twice the price of the Fogstar.

I've been looking around at options as well and wondered if 2x 30Ah would be a viable option - https://uk.eco-worthy.com/products/life ... d_source=1 - 176mm high and 166mm (2x83mm) wide would as well.
 

Titan do a 80AH and 105AH that are 190mm tall, and a bit cheaper than the Lithiumpro place. Got all the bells and whistles (bluetooth, heater etc)
https://www.titanlithium.co.uk/product/ ... -12v-105ah

Looks like that could be an option, 175mm deep so might be a tight fit! Having the bluetooth monitoring would be helpful.

This thread is great timing, my current leisure battery has died and needs replacing, and i so want something with a bit better life, and greater robustness so Lithium seems like a good option.

Current setup is a Sargent EC155 that does the split charging, and their website suggests that it might work with the lithium battery but it's not 100% clear.

The battery websites aren't 100% clear either, and i will check with them before I purchase, but I have 2 questions that others may have dealt with before.

Does a battery that is 190mm high fit under the seat, I tried measuring and it's touch and go. Current battery is 172mm and it fits fine with about 18mm spare. It's close either way.

What is the minimum solar panel size needed to top it up, I really only want a small one that fits on the dashboard to keep it maintained. Any others with experience here would be appreciated.

Thanks in advance.

Al

I'll throw my two penneth worth in here, 190mm batteries WON'T fit under the seat if you have either a swivel or a flush fitting cover, get your tape measure out and see for yourself.

As for charging, those little dashboard type Solar panels will do nothing in the big scheme of things so you'll need either a 'split charger ' or a dc to dc.

The big question is what sort of drain will you be putting on the battery, if you only have led lights, phone charging and a bit of tv you could probably last quite a few days without a charge.

If however you have a compressor fridge, a heater that requires 12v, Propex, Diesel etc, then you'll need a pretty substantial way of topping the battery back up.

I currently have a 215 watt solid panel and a 30amp dc to dc charger linked to a 105ah Fogstar Lithium battery.

The result of an exploding lithium battery.(im not knocking their use. I'm considering getting one myself)
https://www.instagram.com/p/DI...5iWxtp ... A3Z2NwM2pl

Hi, can anyone recommend a lead acid leisure battery for a T25 please?

Needs to fit under the passenger seat, so 175mm limit (I have learned from the thread).
Don't need lots of power, not interested in Lithium options, thanks.

Currently have a Lion 60Ah, which is what some of the parts sites seem to stock (though they say it's 180mm tall).
I guess choice is limited due to space constraints, so is this the only option?

Thanks in advance

Mine is a Yuasa - it cost about 100 quid from my local Auto-Electricians in Tunbridge Wells. My driving battery is also a Yuasa at around the same cost.

Had no problem with either.

I have recently bought a 110L AGM for the white shed on wheels, they also need a smart charger that can deliver 14.8v, usually the "winter" setting.
Will probably add a simple solar array but the main draw will be running the blown air heater over a chilly weekend in spring or autumn so might not even need it.

silverbullet wrote: ↑11 Jun 2025, 06:32 I have recently bought a 110L AGM for the white shed on wheels, they also need a smart charger that can deliver 14.8v, usually the "winter" setting.
Will probably add a simple solar array but the main draw will be running the blown air heater over a chilly weekend in spring or autumn so might not even need it.

Rather than spend a lot of money on a smart dc-dc charger just to do a balancing charge on an AGM now and again, if you use a dual sensing split charge relay (ideally a Cyrix-ct, £40) that'll keep the cost and complexity down.
Instead, rely on the solar charger to push them to 14.8V.
This way you'll also have the benefit of the solar panel keeping the starter battery charged, and a "boost" function which manually ties the batteries together so you can jump start off your leisure battery if required, just by pressing a switch.

AGM don't really need to be charged to 14.8V every time, the 14.2 ish you'll get out of your alternator will charge them up to 99% of their total capacity. Holding them at 14.8V for 30-60 minutes every 5-10 cycles to balance the cells is probably healthier for them than doing that every time, and a decent solar charger (again, Victron - Smartsolar, £55) will do this only when required.

A few other benefits of doing it this way is the Solar charger has temperature/voltage compensation to keep the equalisation voltage at the optimum, and they have a 15A switched load output with current sensing, allowing you to see how much power you're using and also automatically shut off the load to protect the battery if the voltage gets a bit low.

Because I am basically lazy I'll buy something like a portable 100W folding mono crystalline panel with integrated charger and clip it onto the battery terminals when parked up, because we won't be going anywhere.

silverbullet wrote: ↑13 Jun 2025, 07:08 Because I am basically lazy I'll buy something like a portable 100W folding mono crystalline panel with integrated charger and clip it onto the battery terminals when parked up, because we won't be going anywhere.

That's actually not a bad shout. My father-in-law does the same on his caravan

I do the same.

silverbullet wrote: ↑13 Jun 2025, 07:08 Because I am basically lazy I'll buy something like a portable 100W folding mono crystalline panel with integrated charger and clip it onto the battery terminals when parked up, because we won't be going anywhere.

do you have any recommendations for a solar panel? ive been looking but there seems to be a fair few ranging from £70 to £200

i'm going for this leisure battery https://advancedbatterysupplies.co.uk/p ... -12v-copy/
and have a budget of maybe £100 - £125 for a folding panel with controller

I bought a 100W folding monocrystalline panel from Low Energy Supermarket, it has an integral smart controller and for about £90 delivered figured that I can't go wrong.
Evri courier "next day" was a joke, took almost a week! The carboard box was damaged but panel ok as it's inside a padded storage bag.
Nice and weighty too, which I find reassuring.
The cable has a mini Anderson connector so if the supplied 2.5m cable is a bit short I can extend it.
PS I noticed that the prices are all over the place and the big names are selling the same stuff at grossly inflated prices. Why pay £200 for the same item priced at £90?