3 stage or 4 stage battery charger ?? differences please?

[MisterB]

I am looking at buying a Victron Centaur battery charger - it states it is a 3 stage charger, would a 4 stage charger be a wiser move? we rarely go off grid or stay in the same place for more than a night or two, and drive for a few hours each day, we will have 235w of solar aswell as a Battery Master. Any info/advice please would be appreciated

 

[pappajohn]

The 4 stage will include a desuphation stage to maintain a healthy battery

 

[Raul]

No the 4th stage is storage mode where you leave it connected months on end. The storage mode is lower than float, and is activated by prolong float with no cycling. The equalisation mode is a periodic manual or programmed maintenance charge, only on flooded batteries. This maintenance charge should be disabled if auto option is included, on all sealed batteries. You only equalise after taken samples of electrolyte with a hydrometer, and found 15 points or greater difference between cells.
Centaur is a great charger, but, you can get better.

 

[MisterB]

No the 4th stage is storage mode where you leave it connected months on end. The storage mode is lower than float, and is activated by prolong float with no cycling. The equalisation mode is a periodic manual or programmed maintenance charge, only on flooded batteries. This maintenance charge should be disabled if auto option is included, on all sealed batteries. You only equalise after taken samples of electrolyte with a hydrometer, and found 15 points or greater difference between cells.
Centaur is a great charger, but, you can get better.

thanks, £ for £ comparison .... i have been offered a used 50A for £170 ....????

 

[Raul]

thanks, £ for £ comparison .... i have been offered a used 50A for £170 ....????

, I would bite his hand very fast.
A 50a centaur is worth allot more.

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[Guigsy]

If you are rarely off-grid (so don't use hab batteries that much use?), move lots (so hab batteries get a good alternator charge frequently?) and you have 235w solar... do you need a high power battery charger?

I had one in the previous van, but it was cheap and basic one that only did anything at all when the voltage was low. It accidentally left it off one day after playing with the electrics and didn't realise for months. Solar and alternator charging was doing all the work anyway.

 

[MisterB]

, I would bite his hand very fast.
A 50a centaur is worth allot more.

just to confirm, is this a B2B charger that charges the leisure batteries as i drive the vehicle or does it only work from mains hook up?

 

[MisterB]

If you are rarely off-grid (so don't use hab batteries that much use?), move lots (so hab batteries get a good alternator charge frequently?) and you have 235w solar... do you need a high power battery charger?

thats what i am trying to work out LOL - when i meant rarely go off grid, what i meant to say was we dont go off grid for longer than day or two, without driving for a few hours before and after, as we move around. perhaps a better way of explaining is to say we try to camp without EHU as much as possible, but are not often in the same spot for more than a couple of nights.

 

[Raul]

just to confirm, is this a B2B charger that charges the leisure batteries as i drive the vehicle or does it only work from mains hook up

The centaur is a mains only charger.

 

[MisterB]

The centaur is a mains only charger.

thanks, so in reality for my needs, not really suitable, thanks for the prompt response - if anyone else is looking for a well priced 50A centaur charger let me know and i can send you details

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[Guigsy]

thats what i am trying to work out LOL - when i meant rarely go off grid, what i meant to say was we dont go off grid for longer than day or two, without driving for a few hours before and after, as we move around. perhaps a better way of explaining is to say we try to camp without EHU as much as possible, but are not often in the same spot for more than a couple of nights.

In my previous van, I fitted a shunt based battery monitor to my battery, a Victron BMV-712. It's a really good bit of kit that actually works out energy used (Ah) rather than just guessing based on the battery voltage. We had 250w of solar, 100Ah of battery and we rarely hooked up to EHU, but moved pretty much every day. What I quickly found out was I was barely using any of my battery's capacity each day. Between the solar and the driving, the battery never dropped below 90%, even when we were touring in grey days in early March.

In retrospect, but what I didn't fully appreciate at the time was that we were pretty low power users. No TV. Fridge was 3-way. Most of our power usage was LED lights and charging USB gadgets. Our biggest draw was the blown air heating on cold evenings and mornings.

I wouldn't bother with the Victron BMV 712 now the Victron SmartShunt is available as it's £50 cheaper (unless you really like screens). And there are far cheaper shunt based units on Amazon that, while not as adjustable, do pretty much the same job.

 

[Raul]

It is a very good mains charger, that’s it. I have 80a mains charger, and use it only a handful times per year.

 

[MisterB]

In my previous van, I fitted a shunt based battery monitor to my battery, a Victron BMV-712. It's a really good bit of kit that actually works out energy used (Ah) rather than just guessing based on the battery voltage. We had 250w of solar, 100Ah of battery and we rarely hooked up to EHU, but moved pretty much every day. What I quickly found out was I was barely using any of my battery's capacity each day. Between the solar and the driving, the battery never dropped below 90%, even when we were touring in grey days in early March.

In retrospect, but what I didn't fully appreciate at the time was that we were pretty low power users. No TV. Fridge was 3-way. Most of our power usage was LED lights and charging USB gadgets. Our biggest draw was the blown air heating on cold evenings and mornings.

I wouldn't bother with the Victron BMV 712 now the Victron SmartShunt is available as it's £50 cheaper (unless you really like screens). And there are far cheaper shunt based units on Amazon that, while not as adjustable, do pretty much the same job.

so does the smartshunt act the same as the vanbitz battery master or is it purely a way of monitoring battery power? i dont really want to keep checking things, i prefer things just to work away in the background without me having to do anything. i previously had a vanbitz battery master and a 50A sterling B2B and never had an issue

 

[Cush]

The equalisation mode is a periodic manual or programmed maintenance charge, only on flooded batteries. This maintenance charge should be disabled if auto option is included, on all sealed batteries. You only equalise after taken samples of electrolyte with a hydrometer, and found 15 points or greater difference between cells.

Could do with some help
I think my solar charger indicates an equalisation charger judging by the voltage and the charger‘s instructions. Is it dangerous on a lead acid battery or an indication that the battery is goosed? The instructions say that this is at 14.6v (boost at 14.4)

 

[Guigsy]

so does the smartshunt act the same as the vanbitz battery master or is it purely a way of monitoring battery power? i dont really want to keep checking things, i prefer things just to work away in the background without me having to do anything. i previously had a vanbitz battery master and a 50A sterling B2B and never had an issue

SmartShunt is purely for monitoring so you know the true amount of charge in your battery.

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[Raul]

Could do with some help
I think my solar charger indicates an equalisation charger judging by the voltage and the charger‘s instructions. Is it dangerous on a lead acid battery or an indication that the battery is goosed? The instructions say that this is at 14.6v (boost at 14.4)

A equalisation charge is only possible in a safe manner on flooded batteries, the ones you can remove the caps and add water. All other sealed lead acid: vrla, agm, gel, calcium etc. Needs to have the equalisation disabled if is enabled on the charger. If it can’t be disabled you set low values like 14,4v. A charger can never work out when a battery needs a maintenance equalising charge. This is when the end user intervenes manually, or for known repeat maintenance, sets the charger to do a brief equalise charge every 30-60days, depending on battery health. If your charger performs one of this equalisation charge, try disable it. This is meant to be a controlled overcharge, only to correct the imbalance on flooded battery cells. It uses allot of water, hence can only be done on flooded cell, where you have got access, and replace the boiled off water.
If you equalise a sealed battery it can swell, bulge, deform and burst, or overheat into a thermal runway. Depending how much electrolyte is left, how aggressive you equalise, and how many equalising cycles are done. Should be none on sealed lead.

 

[Raul]

Another think to add is, the equalisation starts at the end of bulk cycle, with battery fully charged, and with a max 25% of bulk amps of said battery. For a 100ah battery a charge of C/5 max charge rate would be 20a. The equalisation should be 25% of that, 5a at 16v max. The equalisation stops if temp reaches 50 deC, or when specific gravity has not raised within the hr of equalising.

 

[Cush]

Thank you Raul. I believe I can create a user setting for that in some way. I shall set it to the same as boost charge.