Does anyone have any recommendations or links to where I can get the best value AGM 6v battery for my campervan?

I’ve killed off 2 banner energy bulls (they never seemed that good to be fair).. after 3-4 years… and looking for something that can stand the -20 winters I get in the Alps.. and lower states of charge.

The van has solar and a ctek split charger so lithium is out of the question as it’d mean changing too much stuff and it’s too expensive.. budget is around £400 for a 220ah setup at 12v… I’d love it to be much cheaper though!

I’ve read that AGM are not great to be used as leisure batteries and you’re better off with powerframe* type Bosch batteries (silver).

I’ll see if i can find the details.

Have a look at this

Batteries

Not sure why you want 6V, but you can get a couple of bullet-proof T105 conventional batteries for less than your budget:

https://www.tayna.co.uk/industrial-batteries/trojan/t-105/

There’s an AGM version, but more ££££

https://www.tayna.co.uk/industrial-batteries/trojan/6v-agm/

No lead acid batteries like being in a lower state of charge – they’ll sulphate up.

I doubt your split charge relay will fully charge AGM batteries (the voltage isn’t high enough, even before considering voltage drop in cables, etc.). If you’ve got a lot of solar, that’ll finish off the AGM charging, but -20 in the Alps = not much sun! If you mainly rely on engine charging, especially with AGM, you might be better off spending money on a battery-to-battery charger.

I basically want a maintenance free battery if possible – the location is a bit of a pain to top up water so other than that I have no preference for AGM.. I do have a battery to battery charger too which I hook up every now and then… to be honest I’ll probably store these batteries indoors at a warmer temp over winter as the camper just gets parked up and not used.

I heard AGM let you run 80% of them rather than the standard 50% of the lead acid equivalents… i’ll have a read of that article now

I heard AGM let you run 80% of them rather than the standard 50% of the lead acid equivalents…

I suspect that’s basically true, but the issue is getting AGMs up to 100% in the first place – they (generally) need a long time (several hours) at full charging voltage which is (generally) a bit higher than the alternator / vehicle battery runs at, in order to charge them fully.

It’s easy to habitually run them at part capacity and then they die quite quickly (which I think is why they have a bit of a bad rep in some circles). If you have a decent amount of solar (or mains hookup), that is good for getting them fully charged, but it means a lot of driving if you’re relying on the engine, and with a split-charge relay, they’ll probably never get there.

If you’re storing any lead-acid battery, they’ll still need a top-up charge every few weeks. I don’t think the Banners have a terrific reputation (there was a lot of hype).

If you’re not wedded to AGM, I’ve seen the Halfords HLB 700 recommended over the LFD90 – described as a rebranded Varta EFB (not 6V, obviously, but I presume you’re running a 12V system).

I have the Trojan T105s, they do need the odd water top up although I suspect this is also due to having a B2B charger and solar which presumably works them harder. Also as they are so heavy, its a huge bonus to be able to visually check them without disconnecting and removing them, although you could you probably mark a dip stick to keep an eye on them. The major plus point is they are true deep cycle to 80%, not a glorified car battery with slightly thicker plates. Two 6v T105s gives you 225ahr

Ok so read that link … the ldf90s sound good, I’d need 2 or 3 for my needs. The banners have been average at best from the start so not massively impressed. The ctek charger isn’t too bad but you’re right the main recharge comes from solar so in summer its pretty much 100% charged always.. its the colder months either side of winter that prove the issue.

Good news on the halfords I’ll google that too… Because the Trojans like you just mentioned spooky are true deep cycle 80% does that mean you get more amps out of them in a practical use without damaging them? Or if I dropped them that deep would it take ages to get them back to charge?

I did hear 6v’s paired into 12v handle draw better.

You said visually check them – is there a window or do you still have to take the caps off?

You have to take the caps off. And yes, you get more usable amps. 225ahr down to 80% gives you 180 amps before needing to charge (it will take a bit longer to charge but bulk charging is quick, its the final 20% that takes ages unless you have a smart battery to battery charger).

Two 110v leisure batteries as a comparison would be 220ahr, discharged to 50% gives you 110amps to use.

Remember if you are connecting 6v batteries in series, you add the voltage not the amps, so both my batteries are 6v 225ahr. Joined together they are 12v 225ahr, not 450ahr.

Great, yep all the knowledge I need I’ll be getting a pair of the Trojans – thanks for your help