Which leisure battery ... not what oil

What I really want to fit is a true battery state of charge / level indicator , I've tried a few cheaper variants over the years and I may as well not bothered.

I don't want one that relies on voltage levels to indicate where it's at but something that can calculate actual Ahs somehow , akin to the intelligent battery testers , I'm sure I found something a while back , maybe even @mikedjames might have suggested something ?

Any ideas ?

 

You need a shunt

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I'm sure he's heard worse ...

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https://www.victronenergy.com/battery-monitors/smart-battery-shunt

This type of thing. There are a few on the market with varying levels of sophistication. Your a Victron man though aren't you...

 

Yep victron for the win baby

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As we are talking charging, does it make any difference (with a VSR and both starter and leisure batteries are sealed lead acid) if I regularly do a charge through the hook up point or via a smart charger connected to one of the batteries?

 

Charge in the conventional way Chris with a charger connected to one of the batteries. The VSR should link either way, but as Zed said on a previous post to get the best out of your batteries long term you are best treating them separately.
Chips Ctek is hardwired to the LB, via the consumer unit in the bus, but Ctek do spare leads that I've also got connected to the SB so I can occasionally (once a year or so) give the SB a direct conditioning belt of charge

 

That config means that whenever we hook up, the Ctek automatically kicks in and runs in the background without us having to think about it. Of course with the solar, we don't often have to but it's good for maintenance and keeping the bus on a trickle charge when in storage in particularly cold weather @Chrisd

 

Thanks Neil...I can see a Techenders teach in brewing.

 

Oohh ..yes , I don't know I did but you've confirmed as Matt did that I do need a shunt in my life ...especially a smart one...thanks chaps

 

Word of warning or two. Don't tell it the capacity based on what the battery label says - you have to test and work out the capacity yourself. It will drift out such that you think you've recharged it... but you haven't. They're all a bit rubbish, though if you understand the limitations they are apparently workable and better than nothing as long as you take them with a pinch of salt. Most of what I read tells me you're better off with an accurate voltmeter and ammeter.

 

So a shunt allows the measurement of current flowing out of the battery and this is displayed in various ways .

The way I see it you have to tell the measurement device what the battery size is and it then calculates what's been taken from the battery.

I buy a brand new battery and tell the monitor it's a 100ah battery and is fully charged and assume that's fairly accurate as it's new , the shunt does its job measure what goes out but how does it know what's going in via solar or hookup / charger ,?

As the battery gets older and the true capacity reduces , how do you add the true ah to the monitor - it won't be 100ah any more , the only way I see it is using an intelligent battery tester ?

So isn't there a guage/ monitor out there that works like an intelligent battery tester - across the battery terminals ?

Like Zed says , I can't see them being overly accurate ?

 

Victron shunt with Bluetooth uses an app. Or you can get a fancy gauge but it's expensive for what it does.

One of the guys on here has one already, apologies, I spoke to you at TE and I can't remember your name, who is it @theBusmonkey

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It doesn't, it can't.

Fully charge, discharge with known load, work it out and reset the counter - you should do that even with a new battery.

 

@Dazza

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I agree and understand but if you have to tell a guage or app what the size of a fully charged battery is it's only really any good on a new(ish) battery where the size of the battery on the sticker is somewhere near but 12 months down the line , the capacity is going to be reduced - particularly if it's been run flat accidentally ..

For instance my 100ah leisure battery which can only be 3 years old read something like 20ah when tested with a brand new intelligent battery tester .

I dunno...think I'll just replace it with a middle of the road lead acid and try not to abuse it, hopefully the 100w folding panel I bought last year should reduce the possibilty of flattening it

 

A new battery may say 100ah on it's sticker, but is it? Unlikely though yeah, gonna be closer than your 20ah one! Whether you solar controller undercharges by going into float too soon, or overcharges and boils it... who knows.
I've given up with van, but going lithium in the boat in time not only for the fast charging but also because they don't care a jot for the state of charge!

 

We've just been looking at them at work , I think a couple of us are going to give them a try .. or I might wait for someone else to be guinea pig ..

 

I’ve found the Victron 712 good at monitoring batteries, but it’s certainly not cheap.

 

Possibly me your thinking of, I’ve got the Victron 712 with the gauge.

If buying now, I’d probably not go for the one with a gauge, I hardly ever use it, just go through the app, but if someone isn’t ‘techie’ a gauge in the van might be helpful.

Here’s today’s view after not starting the van for a couple of months, charge is being put in by a Sterling B2B.