Lithium battery?

[ferret50]

I currently have a 100AH deep cycle lead acid battery that I have used in three vans over the last seven or eight years.

Load is mostly a Domtec fridge, bit of lighting, phone/laptop and the power side of a diesel heater.

Modest solar panel/MPPT controller and a battery to battery charger.

Usage is mostly two, two monthish trips UK/Algarve, perhaps 3k miles round trips.

I'm thinking of this.....

https://www.tayna.co.uk/leisure-batteries/sterling...

...as a replacement battery to buy/install this summer. This is a significant cost, am I daft/crazy or should I buy two 100AH lead acid replacements?

[ferret50]

Current battery is struggling on longer nights, our last trip was Jan/April, so fridge was going off going out but just about managing for the return.

The link gives a price, but it's thick end of £500, two lead acid would be about half that. Charging system will cope with either setup, but the litium would take up less room, leaving more for hiding hooch!

[ferret50]

s2sol said:

jfdi said:

What are you gaining other than a bit of space and a weight reduction. 100 amp hours is 100 amp hours regardless of the chemistry. 2x100amp hour lead acid batteries will last twice as long and be half the price. You must really need the space or weight saving to justify it.

100Ah of lead acid gives you about 50Ah of useable capacity. 100Ah of lithium will give about 80-90Ah of useable capacity. This is the ideal use case for a drop in replacement.
Fogstar do a 105Ah battery for a fair bit less than the linked one from Tayna. I've got a 460Ah Fogstar, and it's been a game changer.

Edited by s2sol on Sunday 2nd June 17:13

This one?

https://www.fogstar.co.uk/collections/lithium-leis...

Yes, it is the usable capacity that is a lot of the attraction, any idea on how long these last, please?

[ferret50]

s2sol said:

That's the one. I couldn't say, I've only had mine eight months, but I live full time in the van, so it gets some use. According to the app, it's done 9 charge cycles in that time. Life expectancy is 300-500 cycles, so I'm guessing at about one a month, it'll see me out.

Thanks for your help.

Fulltiming?

I'm afraid that I would miss my home workshop, but I admire those who can cope with the limited space.

[ferret50]

Thanks Spuffy, your LiFoPO4 comes in at £240, whilst brousing they offered me a new customer £10 voucher!

The Fogstar offering is £370, so my selection from Tayna at around £500 delivered does look pricey.

Yet again, knowlegable PH'ers have delivered.

Any more? This is the next purchase after a new clutch, booked in for next week.

[ferret50]

s2sol said:

I used to have a business repairing motorhomes, and I used Tayna or Battery Megastore for replacement batteries. Tayna's customer service is excellent. Battery Megastore was local, and they gave me good trade prices.
I think you'll be delighted with the increase in useable capacity wherever you buy from. Keep the thread updated, I'd be fascinated to hear how you get on with it.

Thanks, I've ordered as the discount woucher was only valid for three days, but I'll try to detail installation and how I get along with it.

[ferret50]

I'm sorry it's taken so long to get back to this with a few photo's, but I've had both computer issues and a damaged back!



Old and new for size comparision. New is also significantly lighter.



New battery fitted and secured, that red lead with the ring goes to the master switch.

Electrics panel back in place, I can access the space to the left of the battery by removing just 4 screws, and last week I tidied the space behind the panel and above the battery with a couple of partitions to give me a further hooch storage place accessed from above by hinging the bed upwards.

[ferret50]

Just to dig this up again, we are sat at Dieppe waiting for the ferry after a 3k miles trip to the Algarve.

Fridge has remained on with no issues using the battery fitted so can only recommend based on my experience.

[ferret50]

We have almost completed our winter warmer trip to the Algarve.

Have a ferry booked out of Dieppe early Tuesday and we have returned this trip via Gibraltar (underwelmed!), Andorra, (cheap gin and Pasitis!) and are currently sat at Chartres for the weekend, we could run over to Dieppe today and try for an earlier ferry but it's sunny here and I have given in to temptation at a LeClerc hypermarket and bought 6 bottles of Gigondas for £64.14! Used to buy this in Calais pre-brexit for about 3 or 4 euros a bottle, a real indicator of French inflation and French following the UK alcohol taxation, perhaps.

I digress, sorry!

Checked battery state this morning when I put the overnight pottie away to see the aux battery sat at 71% charged, just checked again and it's at 80%, so my solar panel is more than capable without the BtoB charger....but I do prefer the belt and braces approach!

[ferret50]

Currently on the Algarve......

My battery appears to be buggered, with the engine running I can measure 14.2v into the B2B charger but only 11.4v out.
Engine off I can measure just 1.54v at the leisure battery terminals, any thoughts, please?

In other clues, the solar panel 'slow burn' fuse was found to have failed, replacement lasted less than five minutes....
Could the solar charger also be fubar?

[ferret50]

Further update...

After taking the 'do nothing and see what happens' approach I monitored the leisure battery over several weeks of short trips for shopping and one a little longer to visit friends, on this trip I missed the junction off the A20 so had to double back and increasing time by half an hour or so.

Next check of the habitation battery showed 12.6v, this held overnight so the battery issue seems fixed, but I have disconnected the solar panel and it's controller until I can check through it's wiring and required fuse values.

So we will have fridge/heat/light for the return trip next month.

Happy days!

[ferret50]

ferret50 said:

Further update...

After taking the 'do nothing and see what happens' approach I monitored the leisure battery over several weeks of short trips for shopping and one a little longer to visit friends, on this trip I missed the junction off the A20 so had to double back and increasing time by half an hour or so.

Next check of the habitation battery showed 12.6v, this held overnight so the battery issue seems fixed, but I have disconnected the solar panel and it's controller until I can check through it's wiring and required fuse values.

So we will have fridge/heat/light for the return trip next month.

Happy days!

Finally got to the bottom of my habitation power supply issues a week or two back.

1 Replaced the solar charger with a bigger one that also charges the front battery and is clever enough to tell the difference between lead acid and lipo batteries.
Still had intermittent power issues at the fridge...
2 Swapped the fridge.
Still had intermitent power issues at the new fridge.
3 Tested every earth return and remade a number of connections/replaced cables.
Still intermitent power at the fridge.
4 Went through the live side and again found a number of poor connectors, being old I now appear to not have the hand strength to make yellow crimp on connectors so bought this....https://www.ebay.co.uk/itm/306305361338 ...and a selection of fittings. I sometimes need to put one arm on the floor and use both hands on the other arm but it gives me a perfect connection every time!
5 The most difficult to access cable is the lipo live to master switch, tested fine on the camper but on the bench the battery end was not clamping properly so was remade.

Got there in the end but it cost far more than it should.....if anyone wants an elderly Domotec 50 fridge let me know!