Battery charger comparison: Sterling vs ProMariner

outwestbound

Observer
Hello. Could you all help me understand which BRAND and/or 12V charger is better? I want to carry a good quality charger on international overland trips that I can occasionally plug into 110-240VAC, 50-60Hz shore power or power with my Honda 2000 generator in a pinch. I have no intention of plugging my shore power mains into any AC power source because of the risk of damage to my rig and I'll live off my batteries via my inverter. I have 260 total amp hours in my bank in the form of 2 6CRV260 6v AGM Crown batts in series, so 130Ah usable. Crown recommends 40 amps charge, so around 15.5%.

Because of undesirable interaction with my solar system, I want a programable charge profile so I can set the absorption point at 14.8 per the battery manufacturer, temperature sensor on the battery post and the ability to ramp the power down from 40amps (ie 75%, 50%, etc.) in case I get a marginal or inadequate AC power source, etc. Both of these have this.

I'm down to these two brand and model dry mount, 12V, 40amp, vented chargers. They appear identical to me (even same case) and are comparably priced. Could you all help select which one to get and why? Thanks

ProMariner ProNautic 1240P

Sterling Power- ProCharge Ultra - 12 Volt, 40 Amp Marine Battery Charger
 

dwh

Tail-End Charlie
They are the same...those two companies were partners.



What is this "undedirable interaction with my solar system" that you mentioned?
 

outwestbound

Observer
Thanks dwh. That makes sense. I made an error in my post regarding "What is this undesirable interaction with my solar system" that you mentioned?"
I got confused. This thread is about a portable charger. That thought of having an undesirable issue with my solar relates to another Sterling charger I'm looking to buy to fix a problem, which is the Sterling Power Battery to Battery Charger 12V input to 12V output 30amp DC powered charger. I have a charger relay (solenoid) in my motorhome that closes when it gets an ignition signal allowing the alternator to charge my house batteries. But, the voltage on my house battery terminals from the alternator is only about 13.5ish, whereas my batts need 14.8, per the manufacturer. My MPPT solar charger polls the battery voltage, sees the 13.5, then goes to sleep because it thinks the batts are full. It's a conflict. Since I only drive 3-4 hour max in any given day, my batts aren't getting full. This issue is conceptual, because I haven't used the rig enough yet, but many have identified this as an issue. This issue has nothing to do with the two chargers that are the subject of the thread.

My bad. Having said that, do you think the Sterling B2B is specified is a good unit? I have a 150 amp Bosh alternator.
 

dwh

Tail-End Charlie
Sure, the Sterling B2B is good stuff, but if you've got that much voltage drop from the alt to the aux battery, you'll probably need to run larger wire for the Sterling...which might fix the voltage drop problem without needing the Sterling B2B.

But only driving 3-4 hours a day - depending on how far the batteries are depleted - will probably only be doing a bulk charge, and even with the Sterling might not have enough absorb time...in which case the Sterling would help some, but not fix the problem. Sure it would get a bit more in the battery by bulking up to 14.8, but the battery will still need some absorb hours.


The solar going to sleep sounds kinda weird, and you'd still have that problem with the Sterling. I'd be looking at some way to fix that...like maybe an on/off switch between the charge controller and the battery, so the controller could be reset to wake it up.

Still, it sounds weird. My first question would be, "Are you certain that's what's happening? Or guessing?" Next would be, "How do you know? Prove it?"

I dont have my current battery/solar rigged to the split-charge solenoid in my van (before I had the solar, the aux battery did charge that way), so I can't confirm, but I don't think my Victron works that way.
 

outwestbound

Observer
Sure, the Sterling B2B is good stuff, but if you've got that much voltage drop from the alt to the aux battery, you'll probably need to run larger wire for the Sterling...which might fix the voltage drop problem without needing the Sterling B2B.

But only driving 3-4 hours a day - depending on how far the batteries are depleted - will probably only be doing a bulk charge, and even with the Sterling might not have enough absorb time...in which case the Sterling would help some, but not fix the problem. Sure it would get a bit more in the battery by bulking up to 14.8, but the battery will still need some absorb hours.


The solar going to sleep sounds kinda weird, and you'd still have that problem with the Sterling. I'd be looking at some way to fix that...like maybe an on/off switch between the charge controller and the battery, so the controller could be reset to wake it up.

Still, it sounds weird. My first question would be, "Are you certain that's what's happening? Or guessing?" Next would be, "How do you know? Prove it?"

I dont have my current battery/solar rigged to the split-charge solenoid in my van (before I had the solar, the aux battery did charge that way), so I can't confirm, but I don't think my Victron works that way.

My info on this "conflict" matter is anecdotal only, but it seems well defined. Several folks in a vehicle specific Yahoo group have mentioned it.

Winnebago used 1 guage to feed the house batteries through a solenoid controlled by an ignition signal. I thought about upsizing it, but my Bosh 150 amp alternator starts at about 14.2ish then settles to 13.8ish at the chassis batt. The alternator isn't ever going to deliver anything like the 14.8 my house batts want (per manufacturer). If SOC were 50%, a seldom event I suspect, I'd run the generator early am an hour or so using my inverter/charger at higher amps (50 maybe) for some bulk, then drive mid to late morning at 30 amps via B2B, then let the solar hopefully finish the process. I have about 500 watts of panels. At 50% SOC and allowing an extra 10%, I'd have to generate 145 Ahs to get back to 100% on the worst day.

I haven't thought through how to deal with the conflict involving the Sterling B2B, if that happens. Both are fully programable, but even if I matched the settings, I doubt each device would be getting the same voltage readings back from the bank. If both were to be set at 14.8, as long as the higher voltage system dominated, this may be a non issue.

When you mentioned installing a switch, a number of folks who have rigs like mine have done that to "open" their charging solenoid and just let solar dominate. I was considering that, but decided having the B2B charger was better since I'll be in South America, where rain and overcast days are many and the sun is at a poor angle anyway. I didn't want to trust my solar so much, when I had a good alternative during driving. But if the B2B also conflicts (which may be a non issue), I could maybe just turn off the panels since I have a blue see red rotary switch in easy reach, or switch the solenoid from the alternator.

I'll have the power systems completed soon then I can get out and shake it down.
 

dreadlocks

Well-known member
any way you can move the B2B closer to the house batteries? All charge sources (B2B/Solar/Shore) should be as close to their batteries as possible for best results.

what are your house batteries? 14.8v seems a bit high for most deep cycles.
 

outwestbound

Observer
any way you can move the B2B closer to the house batteries? All charge sources (B2B/Solar/Shore) should be as close to their batteries as possible for best results.

what are your house batteries? 14.8v seems a bit high for most deep cycles.

Hey dreadlocks. I hope you're well these days. I haven't bought the Sterling charges yet, but yes, I can get the B2B unit close to the batteries - 30" max I think.

Crown 6CRV260 AGMs. 2 6v in series for total of 260Ah @ 12VDC.

I looked at the battery specs and I don't think I'm expressing this correctly. Thanks for pointing this out. Would you please look at the attached. It says bulk 14.4 - 14.7, absorption 14.82, float 13.2. I interpreted this as inputting 14.82 into the solar controller for the absorption set point. So I assume the B2B is current limited at 30amps and that voltage will increase during bulk until it achieves the 14.82, then transition to absorption, where 14.82 will be held constant. Is this right?

I could not tell by reading Sterling's literature how the device transitions into float. Evidently, the charger measures the SOC initially and determines a set amount of absorption time, then just put absorption on a clock. There is no way for it to measure amps dwindling down as the batts get full (the best way I guess), but I suppose the B2B setting absorption off SOC is better than an arbitrary setting by the user. (?)

Thanks for your help.
 

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67cj5

Man On a Mission
Mate, I don't know what country you are in So I hope this helps, For a start I have been doing some serious Battery / Charger ? Fridge testing for the past month or so and to be honest If you want to put back serious Amps back in to your batteries Forget about smart chargers Because if you are going to run them powered by a generator then they just won't do it in time, I have had 4 battery chargers on test and I thought that I needed a smart charger But the truth is unless you have some kind of specialized batteries like lithium etc then get your self a normal compact 25 to 35 Amp linier "Old Fashioned" type charger.

Here's what I did, I ran my fridge for just over 6 days on a 115 A/h lead acid deep cycle battery until it got down to 12.2v, Then I hooked it up to a 15A smart charger and it took forever to fully charge the battery and by time it had finished topping off the battery it was coming up to 32 hours, SO Then I ran the same fridge test and at the 12.2v I then hooked up the 26A version of the smart charger and it chugged away doing its thing and it took ages too, So then I ran the test again and when the battery was down to 12.2v I hooked it up to my wheeled charger that I call "Big Red" I put it on it's lowest setting which is about 9.5 Amps and in just over 6 hours the battery was done,, So that was 12 hours faster than either of the other 2, So then I ran the same test again and after 6+ days I Hooked up Big Red Again Only this time I set him up on the middle setting and in 4.5 hours the battery was fully charged and not only that I also got a higher CCA reading this time too which means the smart chargers don't put out maximum power,

This got me thinking So during the next test I hooked up the 26A Smart charger and checked the Amps it was putting out when first put on charge for and hour or so, and it was reading 1.29A, So divide the rate of discharge by 1.29 and that was how many hours it was going to take to charge that 115A Battery, So Then I hooked up Big Red and he was putting out 5.65 to 5.79 On the Low setting which means he was going to charge that battery 5X quicker that the so called smart charger so then I switch it to the mid setting and the needle shot up and came back down to around 9.35A which is still Ok for a 115A D/C Battery, because the charge rate for a Deep cycle battery of that size is around 20 to 25% of it's overall capacity and as long as you are not going away and leaving it on charge a normal Large Battery charger is the best way to go for doing what you describe, Big Red can put out 35A on High and has a 310 Start / Boost function, But for batteries up to 7-800Amps it's great and on 115A/h batteries I find the mid setting is best which goes between 0 and around 20 Amps,

After doing all these tests where you need the power to be put back in your battery bank ASAP get your self A Normal Compact workshop Battery Charger with an AMP METER not stupid LED's because Smart Chargers tell you Nothing So you never know at what state of charge your batteries are, So buy 30 to 40 Amp Battery Charger, All 3 of these Smart Chargers I'm giving away because they are perfect for maintaining batteries or leaving a battery forever on Charge but They will not perform they way YOU want to use them, For you to run a smart charger to fully charge your batteries then you are going to need about 20 Litres or 5 US Gallons of Gas/Petrol to keep your Generator running long enough in order to fully charge those batteries,

Smart Chargers are Great But not where Time and Generator running costs are key elements, This is not what they are made for, You Need a Proper battery Charger, I have owned Big Red since about 1998/2000 ish and I bought these 3 smart chargers in the last 3 months and to be honest I have wasted Some serious Dough on them, and your needs sound similar to mine like you use the power but you need to get it put back as soon as possible when you get the chance to stop for a while And a Normal Charger is the only way you are going to be able to do that as long as you keep and eye on them, And don't go wasting big bucks on designer Chargers because that's just throwing good money after bad.

Hope that helps.
 
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67cj5

Man On a Mission
Thanks for the help. I'm in the USA. I'm glad you found a solution that makes sense. I'm still studying whether a B2B charger makes sense. Thanks again.
I re did the test today using Big Red to recharge the 115A deep cycle battery once it was down to around 12.4v and on the medium setting it took 2hrs 53mins to get the input voltage up to 14.39 volts and At 3 hours it was reading 14.51 Volts which means it was just about fully charged, On the Medium setting it puts out about 18 to 20 max But when I first turned it on it was accepting 12.5 Amps and At first it Spiked at around 15 Amps and dropped down to 12.5 Amps as it began to Charge,

I still believe that The Old fashioned Linier Type Chargers are the best for your application because of their shear power out put in the shortest possible time, No smart charger can do that because of the pre set software, I will Always be using the Older Type Chargers for Bulk type Charging of this nature and the only time I will use the Smart Chargers is when I have time to use the Repair/ Desulphide Mode Or if I need to leave a battery on permanent Charge, other than that I see no use for them,

I have tried this test over and over and this is the fastest way to put back the power in to a battery, and it is even more effective than using the Vehicles Alternator because the rate of charge is Constant and not governed by RPM, Although Smart charger companies make wild claims about them being twice as fast as Normal type chargers 7 tests out of 7, I have found that this is not the case. And I have just wasted over $6 to 700 dollars on smart Chargers to find this out, I need power when I need it Not when some Software decides that I can have it, AND another Major PIA with Smart Chargers is The companies claim that they have a memory so if the input power gets disconnected that the Smart Charger remembers what it was doing and it carries on where it left off when it was disturbed, Sadly this is not the case, They Only remember the MODE they were In before they were disturbed, So when the power is restored these smart chargers Start their complete cycle all over again Because of their Pre Set Software So all that lost time is wasted As it puts you back to Square One, Where as a Linier type charger just carries on as normal as it just see's the battery in a different state of charge.

The term "Smart Charger" By Name only Is a Lie in it's Self, The correct Term should be "Pre Set" Charger because it is governed by pre set software, Where as the Liner Type Charger only puts out what the battery Wants and has user adjustable charge rates and supplies the user with valuable info in return.
 
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outwestbound

Observer
I re did the test today using Big Red to recharge the 115A deep cycle battery once it was down to around 12.4v and on the medium setting it took 2hrs 53mins to get the input voltage up to 14.39 volts and At 3 hours it was reading 14.51 Volts which means it was just about fully charged, On the Medium setting it puts out about 18 to 20 max But when I first turned it on it was accepting 12.5 Amps and At first it Spiked at around 15 Amps and dropped down to 12.5 Amps as it began to Charge,

I still believe that The Old fashioned Linier Type Chargers are the best for your application because of their shear power out put in the shortest possible time, No smart charger can do that because of the pre set software, I will Always be using the Older Type Chargers for Bulk type Charging of this nature and the only time I will use the Smart Chargers is when I have time to use the Repair/ Desulphide Mode Or if I need to leave a battery on permanent Charge, other than that I see no use for them,

I have tried this test over and over and this is the fastest way to put back the power in to a battery, and it is even more effective than using the Vehicles Alternator because the rate of charge is Constant and not governed by RPM, Although Smart charger companies make wild claims about them being twice as fast as Normal type chargers 7 tests out of 7, I have found that this is not the case. And I have just wasted over $6 to 700 dollars on smart Chargers to find this out, I need power when I need it Not when some Software decides that I can have it, AND another Major PIA with Smart Chargers is The companies claim that they have a memory so if the input power gets disconnected that the Smart Charger remembers what it was doing and it carries on where it left off when it was disturbed, Sadly this is not the case, They Only remember the MODE they were In before they were disturbed, So when the power is restored these smart chargers Start their complete cycle all over again Because of their Pre Set Software So all that lost time is wasted As it puts you back to Square One, Where as a Linier type charger just carries on as normal as it just see's the battery in a different state of charge.

The term "Smart Charger" By Name only Is a Lie in it's Self, The correct Term should be "Pre Set" Charger because it is governed by pre set software, Where as the Liner Type Charger only puts out what the battery Wants and has user adjustable charge rates and supplies the user with valuable info in return.

Are you within the battery manufacturer's specs on charge rate? For example, my Crown 6CRV260s (2, 6V batts in series for 1, 12V 260Ah bank) recommend no greater than 40amps charge rate, which is like 15.5%. They say in their specs a "max" of 80 charge rate, but when I called, he said not to exceed the 40 aps if possible as mine are AGM style batts.
 

67cj5

Man On a Mission
Are you within the battery manufacturer's specs on charge rate? For example, my Crown 6CRV260s (2, 6V batts in series for 1, 12V 260Ah bank) recommend no greater than 40amps charge rate, which is like 15.5%. They say in their specs a "max" of 80 charge rate, but when I called, he said not to exceed the 40 aps if possible as mine are AGM style batts.
Yes I am, Being a Wet deep cycle battery they are more forgiving and can handle charge rates of up to 25% +, The 10% rule applies to Car batteries not deep cycle batteries,

Have a quick read of this, There is a lot of info on their site,

 

67cj5

Man On a Mission
Also AGM's can be charged at a rate of up to 30% charge rate, So a 100Ah battery can be charged at 30Amps.
 

outwestbound

Observer
Also AGM's can be charged at a rate of up to 30% charge rate, So a 100Ah battery can be charged at 30Amps.

I wonder if I misinformed the Crown battery guy. He may have been thinking I was talking about only one 6 volt battery that had the 40 amp charge recommendation.

Since I put two together in series for a single, 12V, 260Ah battery, does that affect the charging rate calculation on the manufacturer's specs?
 

67cj5

Man On a Mission
I wonder if I misinformed the Crown battery guy. He may have been thinking I was talking about only one 6 volt battery that had the 40 amp charge recommendation.

Since I put two together in series for a single, 12V, 260Ah battery, does that affect the charging rate calculation on the manufacturer's specs?
The Charge times, If they are 2 X 260's @ 6v in series making 12v would be the same as a single 12v 260A battery, but if you had them running in parallel As 6v you would end up with 520A/h,

260A/h divided by 100% = 2.6 X 30% = 78 Amps,,, So you could charge them at a rate of 78 Amps per Hour If you wanted to, and at 10% = 26 Amps per hour and 20% = 52 Amps per Hour, So you have quite a flexible system so I would be looking at a Charger that can put out about 30 "35" to 50 Amps per Hour, Not only that if you are only running them down to the 50% mark then that's only 130 Amps So a 35/50 Amp Charger like the one in that link would be just the ticket and they put out about 400Amps for boost starting. And the price is right Too, I have had my Wheeled version since about 1998/ early 2000's So they go the distance And no doubt you can buy them for about 120 to 180 buck in the US.

This is what I would /// Will be buying because I have the Wheeled version and although it has the same Charge rates the Wheeled version Stands over 2 feet tall and weighs about 35Lbs +.

 

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