Which leisure battery ... not what oil

Yes, you were who I was thinking of, my memory for your name escaped me.

Sent from my Pixel 6 Pro using Tapatalk

 

How’s your Sterling lithium battery going? I’m still rather tempted

 

Yep, it's still all good. I wouldn't go back now from a lithium for leisure now.

Sent from my Pixel 6 Pro using Tapatalk

 

I don't do off grid, I am not much cop at charging when I get home either. I don't camp without electricity if I can help it, battery is only used to power the fridge when at the beach, a regular occurrence, Powers Chinese diesel heater until we set off if its cold. Got a 100w solar on the roof. Last one lasted 3 1/2 years I think. went cheap again. Terminals are wrong way but it does not move so all good.If it lasts the same time again I will be happy. https://www.ebay.co.uk/itm/272289168572

 

Reviving thread after research and much thought. Still undecided between normal or AGM leisure battery. Couple of weeks ago I bought a normal Halfords leisure battery on line (HLB700 £88) but when I went to pick it up it was gone. Young kid in shop said it must have been nicked and it was the last one so I got a refund. This give me the chance to rethink the normal vs AGM scenario all over again.
Keeping the set up I have now- Good quality basic split charge relay. New mains to 12v power supply. Ctek mxs 7 charger with agm option.
OPTIONS,
I could stick a normal leisure battery in and be done. Alternator tops up when driving and Ctek set to normal when hooked up.
I could fit an AGM leisure battery. Alternator tops up when driving and Ctek set to AGM when hooked up.
My only concern is how the AGM will handle the basic alternator output. Will it be damaged. If so I could just disconnect the split charge relay altogether.
I’m possibly over thinking it but the AGM does seem to be a better choice for not much more money.

 

Won't the AGM just be under charged when running off the alternator?

 

Yup.
@vinnyboy , As soon as you connect the batteries together in a system you are effectively creating a single battery that requires 2 different charge profiles and utilises 2 different types of battery chemistry.

If you want AGM, just keep it separate from the starter battery and split relay or spend 200-300 quid and get a battery to battery charger that can link 2 chemistries by changing charge outputs.
As I said above, it'll work fine but you are shortening the life of potentially both batteries which then sort of defeats the object.
If you only use hook up, go for it, but keep them separate and take out the split charge if it allows 2 way charging. The higher charge needed for the AGM from the ctek will damage the starter if they are connected.
Your bus, your choice.

 

Thanks for the advice @theBusmonkey ,
So if I go for AGM keep it separate. All good.
In your opinion Is it worth sacrificing alternator top up for the advantage of AGM over normal.

 

When you change to lithium make sure either the batteries are housed inside a heated area of the boat or you buy batteries with the in built heating function.
Lithium batteries don’t like very cold temperatures and you don’t want power problems in winter.
You will also need a battery to battery charger with a lithium profile to allow the alternator to charge them properly.
You can get ones with a solar input aswell .

 

Honestly Vinnyboy, in my opinion it isn't.
There are a couple on here who do run big AGM banks but they are topped up from solar iirc.
We've just bought a new FLA for Chip.
It was a little more expensive than the Halfords one you linked, but one it replaces is 4 years old and still going strong.
I've simply swapped it into the boat to use as a starter battery.

This is the one we use. It may be too big for your set up as I've modified the spare wheel well.
I like these because I can remove the cell caps periodically and top them up.

https://www.countybattery.co.uk/leisure-batteries/powermarine-6115-premium-marine-battery-115-amp/

However, we don't use hook up so much, have 180w of solar on the roof and therefore I can constantly keep the batteries in good condition. Either through the solar mppt or the ctek for top up maintenance.
We run a Dometic CFX35 fridge, propex, water pump, tunes, lighting and all charging requirements off the 115ah battery.
It just becomes a case of being sensible with power use, otherwise the batteries get hammered anyway.

I've tried AGM, with the Durite VCR, and the solar controller charge which has to be higher for the AGM cooks the SB which ejects it's acid into the battery tray...

 

We've gone for this @paradox following the disappointing experience with the Sterling 1230, which doesn't actually function as an mppt charger.
It's not been fitted yet, but come with the suppliers wholehearted recommendation as being a superior unit in all aspects.

http://simplysplitcharge.co.uk/abso-dmt1230-30amp-battery-to-battery-charger-solar-mppt.html

You are right about lithium and cold temps. They will work, but they won't accept a charge

 

It's a lot more complicated than that. B2Bs waste a lot of power and cost a lot of money for what they do and spend too much time throttled down to 1/2 their already throttled output - eg from a 90A alt you might be charging at less than 30A. An alternator controller/regulator seems to be the way to go for normal alternator charging as Lithiums will suck a lot of power from the alt and overheat it. You need to fist balance cells, stop the charging when either the bank or a cell is up to the knee, stop discharge before it's down to about 10%, stop charging at low temp, etc etc. I have a 120A mains charger and a 3.5kva mains generator attached to the engine which I'll use rather than my domestic alternator. That pairing is designed to put out high power for long Idea being to whack a lot of amps in fast as I'm likely to go for about 4-5-600ah of batteries - not decided yet but I know my studio PC will gobble a lot of AH. To stay safe from over/under soc it seems recommended to adopt a 20-80% useage or if you're better in control 10-90%. The "you can use 100% capacity" is not true, but the fast charging and the batteries producing solid power at any state of charge and not sulphating when left part charged are the attractions for me.

 

Great
We like to travel around, staying a couple of nights here and there, but mainly with hookup. On the nights without hookup we would only use radio, lights and possibly tv. I think normal battery is the way to go.

 

B2Bs seem like a poor way forward. Is that "30" input or output?

 

My brain hurts , have I stumbled upon some weired witchcraft forum ??



Sent from my SM-G960F using Tapatalk

 

30 amp regulated output to keep the lithium's happy.
They are fickle mistresses, stupidly expensive and you're totally dependent on a BMS that sometimes decides to work, sometimes doesn't.
I'm sure that once the systems are in, they will be fine. I do like the lithium batteries though. I just hope all the messing about will be worth it in use.
We can run the straighteners and hairdryer off them though...

 

How will you stop it over charging? I read you can set them to go into float at whatever you decide based on how fast you are charging but set the float low so effectively they stop charging. Problem then is stopping the thing topping up the battery all the time because your lithiums don't like being held at or near fully charged. From my point of view unless you are having a big bank, the crud to control the charge and discharge is too complicated and expensive to be worth the hassle.

 

You're right of course, but the benefit we have in our boats over the van is space.
It's a lot simpler to spec 5 to 600 ah and keep the bank happy.
Plus, we are both living off those systems so it becomes a lot more life critical, for want of a less dramatic term, to keeps the beans flowing down the cables.
We are, some of us, as @Lasty implies prone to over complicating our van set ups.
Hence, for the bay its standard batteries, standard alternator, a split charge relay that won't pop if you run down the LB and a fridge that makes ice for GnT...

 

I'm going to make it switchable. Like the calorifier that's also going in the van.
We don't need hot water all the time so I have a 12v solenoid that will control coolant flow.
Same with the lithium charger. I suspect the b2b will only be required occasionally as a portion of the solar will be dedicated to the house bank.
The beauty of the lithium's is that they accept charge way quicker than the FLA. Therefore it doesn't have to be on all the time