what charger

[glenn a]

need to pick your brains. ive got 4 ... powertrak 6v semi traction 232ah batteries wired to produce 12v. ive been looking at the sterling range of smart chargers but unsure what amperage to go for. any advice would be much appreciated

[WotEver]

40A would probably do fine but a 60A would save you a little time if you're off-grid.

[nicknorman]

need to pick your brains. ive got 4 ... powertrak 6v semi traction 232ah batteries wired to produce 12v. ive been looking at the sterling range of smart chargers but unsure what amperage to go for. any advice would be much appreciated

You need to tell us the intended usage. If you are on shore power, there is no point in getting a big one - 20A will suffice. If you are mostly charging from a generator then I'd say as big as you can afford within reason, say 60A. BUT be careful that your generator can actually run a big charger. They tend to have large start-up surge demands and / or out-of-kilter power factors which can scupper some gennys. And of course you need to read the small print of the genny spec to see what the continuous rating is.

 

In the end it is a compromise between up-front cost for a big charger vs longer genny running time for a smaller charger. Oh and I presume you mean the Pro Charge Ultras, which have the advantage of fully adjustable charge voltage (well up to 15.1v anyway).

Edited January 10, 2017 by nicknorman

[sleigh]

I replaced mine with a end of line ...Ring Smart Charger Pro RSCPR50 stunningly robust construction, rubber end caps on casing, silent running, additionally there's a plug and play remote display(SmartCharge Pro Remote Control RSCPRC) for handy tinkering, function changing or actually seeing battery voltage.

i think the 50A from local motor factors was under £80 with the extra remote coming in at around £17.

​I purchased another 35A for use with my classic cars... highly recommended

[sleigh]

This model style...

[nicknorman]

I replaced mine with a end of line ...Ring Smart Charger Pro RSCPR50 stunningly robust construction, rubber end caps on casing, silent running, additionally there's a plug and play remote display(SmartCharge Pro Remote Control RSCPRC) for handy tinkering, function changing or actually seeing battery voltage.

i think the 50A from local motor factors was under £80 with the extra remote coming in at around £17.

​I purchased another 35A for use with my classic cars... highly recommended

 

I have to say I'm struggling to see what is wrong with that charger. In particular I note the Calcium mode that seems to well replicate the charging algorithm for semi-traction batteries (ie a high finishing voltage) and the reconditioning mode that gives it up to 16v for 4 hours. Seems like a very good find.

[Neil Walker]

I replaced mine with a end of line ...Ring Smart Charger Pro RSCPR50 stunningly robust construction, rubber end caps on casing, silent running, additionally there's a plug and play remote display(SmartCharge Pro Remote Control RSCPRC) for handy tinkering, function changing or actually seeing battery voltage.

i think the 50A from local motor factors was under £80 with the extra remote coming in at around £17.

​I purchased another 35A for use with my classic cars... highly recommended

£80??? Where! Serious 'end of line' bargin. I can't find under £230 looks good though

[OldGoat]

I am of the opinion that if you charge the batteries slowly - assuming you're on a landline for the mains power (you didn't say otherwise), then time is not of the essence.

To add credibility to the above looky here:-

 

https://www.tayna.co.uk/Trojan-Marine-Leisure-Batteries

 

You'll see that there's quite a difference between fast charge rate - capacity / 5 and leisurely C / 100, with C/20 which is the usual recommended rate.

Edited January 10, 2017 by OldGoat

[WotEver]

I am of the opinion that if you charge the batteries slowly - assuming you're on a landline for the mains power (you didn't say otherwise), then time is not of the essence.

Oh yes, that's absolutely correct. On shore line as long as the voltages are correct and as long as the charge current exceeds any on-board demand then the smaller the better.

 

It depends on how often you cruise of course, there's little point in having a charger that will take 36 hours to charge the batteries if you're going back out in 14 hours.

[sleigh]

I got the pair of mine from Parkers auto parts in Newark on Trent.

[dmr]

I also struggle to find anything too wrong with this charger, in fact it looks quite good.

The instruction book says some slightly questionable things about Calcium batteries.

The automatic equalisation/finishing to 16v could be the big issue, I would never want such a high voltage to be applied automatically on every charge, it might destroy something, but it sounds like this can be avoided by not selecting the calcium mode.

The instructions say that having other stuff connected whilst charging is not ideal, this is unavoidable on most boats, dunno how much this will confuse the charger.

Big question is, does it do a good charge before going into float?

The initial pulse desulphation phase is a bit suspect/gimmicky.

 

As a boater with a Travelpower it would be really good if a charger could work in collaboration with the alternators to add its output to the alternators during the bulk phase, I don't think this one would be happy with that.

 

...............Dave

Edited January 10, 2017 by dmr

[blackrose]

The only trouble with most of the small, budget single-output smart chargers, is that they tend to put out a maximum of 14.4v. Fine for sealed batteries, but not ideal for wet lead-acids.

[dmr]

The only trouble with most of the small, budget single-output smart chargers, is that they tend to put out a maximum of 14.4v. Fine for sealed batteries, but not ideal for wet lead-acids.

 

Yup, very true, but this one has a "chemistry selection" which is a bit like a voltage selection but sounds more clever, and goes up to 14.7v for batteries with a lead acid chemistry (I am been a bit silly and cynical here, is there a smiley for that?).

 

Just spotted another little issue, the equalise/recover option applies a fixed current till the voltage gets up to 16v. This is strictly the good way to do it but might go 'orribly wrong if any load is connected.

 

still a good looking charger for non liveaboards though.

 

...............Dave

 

edited to remove this spurious second signature:.................Dave

Edited January 10, 2017 by dmr

[blackrose]

 

Yup, very true, but this one has a "chemistry selection" which is a bit like a voltage selection but sounds more clever, and goes up to 14.7v for batteries with a lead acid chemistry

Well if it has battery type selection then that sounds fine for most users apart from anyone running it from a generator.

[dmr]

Well if it has battery type selection then that sounds fine for most users apart from anyone running it from a generator.

 

It even has the option to work at reduced output currents so should be fine on a generator. This looks like a very good charger but its software is optimised for charging vehicle batteries in a workshop rather than boating or camper use where loads are also connected.

 

..............Dave

[nicknorman]

 

It even has the option to work at reduced output currents so should be fine on a generator. This looks like a very good charger but its software is optimised for charging vehicle batteries in a workshop rather than boating or camper use where loads are also connected.

 

..............Dave

 

But then if you want to charge your Trojans correctly, you have to accept that there will be some pretty high voltages on the system that are likely to damage some stuff rated only at 12v, and therefore it wouldn't be too unreasonable to expect to have to turn stuff off near the end of the charge process. I will give you that fridges don't fall into this category since they are designed to operate over a wide supply range, so yes you will have to turn the fridge off during the conditioning or equalising bit. But what other means of getting a winter equalising voltage is there? Everything has its compromises!

[dmr]

I did look at some voltage range specs when I first got my Trojans, can't remember the details but my conclusion was that 15.5volts is ok for everything on the boat but at 16v a couple of items were very marginal. I think it was the radio and computer power supplies (12 to 19v things) that were in danger but not sure of this.

 

I never turn anything off when I equalise (at 15.5) but at 16 I would want to turn some things off.

 

The Trojan finishing voltage has been of "academic interest only" up to now as no chargers do it, but now we have found a charger that can.

 

I don't want to turn stuff off every time I run the engine so I would much prefer a finishing voltage of 15.5 maximum even though the Trojans might like a little more. Equalising at 16v is ok as we don't equalise very often so turning stuff off is viable. Sounds like this charger could maybe do this by not selecting the calcium option, though it does sound like it might go into the recondition mode automatically which is not good.. Again, cant really blame the charger as its probably intended mostly for charging disconnected batteries but the instruction book should contain a warning about the dangers of 16 volts.

 

Its not a big deal as it does sound like this is not an ideal charger for charging with loads connected.

 

...............Dave

[blackrose]

 

But then if you want to charge your Trojans correctly, you have to accept that there will be some pretty high voltages on the system that are likely to damage some stuff rated only at 12v, and therefore it wouldn't be too unreasonable to expect to have to turn stuff off near the end of the charge process. I will give you that fridges don't fall into this category since they are designed to operate over a wide supply range, so yes you will have to turn the fridge off during the conditioning or equalising bit. But what other means of getting a winter equalising voltage is there? Everything has its compromises!

My last set of batteries were charged by a 30amp sterling with a max voltage of 14.8v. They lasted 10 years and were still ok when I scrapped them. They'd just lost a lot of capacity over the years, but they still held a decent charge. I suspect a lot of this charging regime / higher voltage equalisation stuff is really for the electrical purists and in practical terms if you keep them charged it doesn't really make that much difference.

[MtB]

My last set of batteries were charged by a 30amp sterling with a max voltage of 14.8v. They lasted 10 years and were still ok when I scrapped them. They'd just lost a lot of capacity over the years, but they still held a decent charge. I suspect a lot of this charging regime / higher voltage equalisation stuff is really for the electrical purists and in practical terms if you keep them charged it doesn't really make that much difference.

 

Mike, I seem to remember a post from you a few months back where you'd found a cheap supplier of de-ionised water. I asked why the price mattered as only tiny volumes are needed but you replied saying you add it to your batteries by the litre (or word to that effect).

 

This is not normal and suggests to me there is something unusual about your charging regime. Even when I equalised my batts the other day the electrolyte level barely changed. I NEVER seem to need water to my batteries yet you need to add loads.

 

Can we perhaps investigate why?

[dmr]

My last set of batteries were charged by a 30amp sterling with a max voltage of 14.8v. They lasted 10 years and were still ok when I scrapped them. They'd just lost a lot of capacity over the years, but they still held a decent charge. I suspect a lot of this charging regime / higher voltage equalisation stuff is really for the electrical purists and in practical terms if you keep them charged it doesn't really make that much difference.

 

I assume you are not an off-grid liveaboard, if you are then ten years from a set of batteries is very good, in fact almost unbelievably good. Did you have so much overcapacity to start with that you can afford to loose most of it and still manage?

 

Equalisation is a necessity for me and I couldn't do without it. As an engineer I am interested in this stuff and like to understand it but I'm not a purist, equalisation is a chore that I could do without. Bottom line is that I can just about go two days without an engine run but the capacity gradually falls off till I am barely able to go a full day (22 hours for the pedants) without an engine run which is not good, I equalise and the lost capacity comes back. That's a huge difference!

 

I accept that if I did a full charge at 14.8 volts for several hours on every charge then I might get by with very little equalisation, but in the winter if i'm not cruising I only run the engine for a couple of hours,

 

...............Dave