OJ's dual battery system review

[Josh]

I haven't seen this discussed (the recent winch test was critically enough reviewed:Wow1.

I'm not too sharp with this stuff but maybe someone who is could assure me that Hellroaring Technology got a fair shake in this test.

First it seems like the model OJ reviewed, the BIC95150B, is a distant runner up (in preformance specs at least) to HT's other, more popular model, the BIC95300B (my amateur assessment). It's a maybe like testing a stripped down Mercedes against a fully loaded Ford.

OJ didn't (couldn't?) really find any fault in the tested HT BIC at all. Except that, in the conclusion piece, they gave warning that buyers beware voltage loss in systems of that type. Maybe I'm missing something but in my (amateur, again!) reading of HT's specs I don't see any appreciable voltage loss... as in more voltage loss could be expected from one's battery cables than from the unit itself.
But the damage is done. The casual reader comes away "educated" that "OJ tested a Hellroaring BIC and those systems suffer from voltage loss".

And, at the end of the day, the friggin' thing's $200 dollars cheaper than The Choice! That could buy you a really nice battery to make your system "dual".

I know it's pure heresy to say anything that might have even the faintest odor of criticism for the OJ scriptures. And let me be clear, this is not criticism!! I'm just not clear if I'm either misunderstanding something or seeing something not there....?? Would just like it clarified.

Thanks and kind regards, Josh

 

[ntsqd]

If the HR uses diodes in their primary dividing system, then there will be a voltage drop. I've no idea if they do or do not have diodes in them.

As far as I'm concerned there are alternatives that are both better at what they do and less expensive. I don't want nor need all of that complexity combined with an easy to bump switch that could leave you stranded. Give me an Automatic Charge Relay or a Voltage Sensing Relay (same thing) wired in parallel with a marine battery switch and I'll be on my way. That's about $100-$125 worth of equipment.

 

[James86004]

I have read about the existence of Voltage Sensing Relays, but how do they work? Explanations of electrical stuff with water analogies work particularly well for me

 

[ntsqd]

I'll put in the water analogies, but I'm guessing that in this case you really don't need them.

They're just a high current (flow) relay (valve) with some circuitry that monitors the main battery voltage (pressure). When the charging system is running and the main battery has been recharged the relay turns on to charge the secondary battery. When the charging system stops the relay turns off. Automagic!

They won't carry starting currents as they only intended to charging work. That is why I suggest wiring one in parallel with the marine switch. Then a self-jump start is a not so easy to do accidentally turn of a switch.

This is the one that I've set aside for the FJ60:
http://www.delcity.net/store/Voltage-Sensing-Relay-!-Single-Sense/p_793852.a_1
Whoa, it's gone up $4 since I bought mine! John (whatcharterboat) mentioned these in a post a while back and in researching them I found that one of my normal suppliers was stocking them.

Blue Seas' ACR's:
http://bluesea.com/category/2

 

[Robthebrit]

As far as I know HR use a solid state relay (basically a huge Field Effect Transistor) and not a simple series diode so there should be no voltage drop, maybe a tiny bit but nothing like the 0.7 volts you would get on a diode (the 7 series definitely do not use a diode, not sure about the older ones). The size of the heat sink would back this up, lower voltage drop equals less power disipated, the HR heat sink its much smaller than a simple diode combiner.

What happens inside the combiner is only half the problem, what most people don't talk about is what happens when you stress them or even overload them, for example you try to start from the aux battery or run the winch. I welded a Xantrex 150A single solenoid combiner shut by trying to start my old yellow doka mog from the aux battery, I am not sure what a solid state relay would have done in this scenario.

One huge advantage of a solid state relay is that it can be used inside the battery compartment without any risk of igniting charging gases.

Rob

 

[goodtimes]

I haven't seen this discussed (the recent winch test was critically enough reviewed:Wow1.
. . .

I know it's pure heresy to say anything that might have even the faintest odor of criticism for the OJ scriptures. And let me be clear, this is not criticism!! I'm just not clear if I'm either misunderstanding something or seeing something not there....?? Would just like it clarified.

Thanks and kind regards, Josh

First, let me assure you that honest and open minded debate about the Overland Journal's articles is not heresy. Open minded, friendly debate is a good thing. Things don't turn ugly until minds close and discussions become vindictive.

Second, there *is* a voltage drop with that style isolater/combiner. And the higher the load, the higher the voltage drop. I know. I measured it in preperation for that comparison (the BIC that was tested has been in my jeep for a year or two).

As for the selection of that particular Hellroaring unit, I selected it based on the recommendation of the Hellroaring, at the time of purchase.

There are "better" systems out there, and there are "cheaper" systems out there. But that doesn't mean the Hellroaring unit that was tested is "bad"....it isn't. I am completely satisfied with the Hellroaring BIC, and with the price that I paid for it. It is still mounted under the hood of my Jeep, and I have no intention of replacing it (assuming it continues to function properly--and there is no indication that it will not).

Just to be included in the comparison is saying something in and of itself. If you haven't noticed, there has not been any "cheap junk" in any of the reviews. The comparisons are between the best of the best.

 

[James86004]

I'll put in the water analogies, but I'm guessing that in this case you really don't need them.

They're just a high current (flow) relay (valve) with some circuitry that monitors the main battery voltage (pressure). When the charging system is running and the main battery has been recharged the relay turns on to charge the secondary battery. When the charging system stops the relay turns off. Automagic!

How does it measure the voltage while it is charging? When I put a voltmeter on battery terminals when the engine is running, it shows the charging voltage.Even after I remove the charger, it takes many seconds for the voltage in the battery to drop before leveling off.

 

[kjp1969]

My only criticism of the OJ article is that it almost ignored the simplest, cheapest and most bombproof choice, a simple marine switch. It was mentioned in passing, but then disregarded. I would liked to have seen inclusion of one of those. The last one I bought was $39 from West Marine. Sure, it's a frumpy manual switch, but it works and is unlikley to fritz out.

That's a theme I would carry over to other OJ articles as well- I'd like to see a short "what-about-the-rest-of-us" sidebar accompanying stories about some of this uber-cool equipment. It would show a dirt cheap but serviceable alternative that gets you most of the function of the expensive gear, but at a fraction of the cost.

$2500 rooftop tent? $100 Walmart ground tent.
$700 Engel? $40 ice chest
$600 collection of Zarges cases? $100 collection of Actionpackers.
$10000 KTM? $3000 used KLR 650

As much as I love the OJ articles and enjoy reading about the "best of the breed," I sometimes get the feeling that they're a bit heavy on the gear, a bit light on the function. A notable exception to this criticism was the duffel bag article, which included some downright cheap and perfectly serviceable alternatives. Great contrast and food for thought!

 

[Robthebrit]

It tells you right on HT's webpage what the on-state resistance of the relays is (http://www.hellroaring.com/industr.php)

The best case is 0.001 ohm so with 100A passing you would drop 0.1 volts, the worst case is 0.006 ohm so with the same 100A you would drop 0.6 volts which is not really any better than a series diode (this worst case is for a 24 volt system but even so its still no better than a diode).

From looking at the specs of the relays and comparing to the specs of the isolators I am guessing the average volt drop would be in the order of 0.2v at 100amps.

The reason these don't interfere with charging like a series diode does is because as the voltage of the battery rises the current consumed by the battery drops and therefore the voltage dropped by the SSR also drops.

Rob

 

[Josh]

...

Second, there *is* a voltage drop with that style isolater/combiner. And the higher the load, the higher the voltage drop. I know. I measured it in preperation for that comparison (the BIC that was tested has been in my jeep for a year or two).

....

You say "there *is* a voltage drop".

OJ warned me to "..check the manufacturer's rated voltage loss...".

I guess what I'm after here is for a savvy someone to look at HR's spec sheet (for both the 95150 and 95300 if possible) and translate that data for me so that I can make the informed decision that OJ admonishes.

I say "translate" because I've scavenged their website and I'm not seeing it in their information. And PROBABLY because I don't know what to look for.... OR Hellroaring is not being forthcoming... OR OJ is making much ado over not much...??

Kind regards, Josh

 

[Josh]

It tells you right on HT's webpage what the on-state resistance of the relays is (http://www.hellroaring.com/industr.php)

Rob

Are we talking about their SSR's or the BIC's? Or are they more related than I realized?

I found that the BIC95300B claims a "Max On Resistance (at 10amps) of 0.001ohms". I have to admit to not really knowing what that means in a real world way.

Kind regards, Josh

 

[gjackson]

I've been using a Hellroaring system for 5 years in my 110, and, apart from the time I set it on fire through total ineptitude, have never had a problem with it. I think it is a pretty nice solution. That being said, I have never had to start the vehicle with a dead main battery off the house battery. Truth is, for my application and for most overlanders, the house is the battery that goes flat fastest and the Hellroaring certainly has protected my main vehicle battery from the house.

Just my experience.

cheers

 

[Robthebrit]

Are we talking about their SSR's or the BIC's? Or are they more related than I realized?

I found that the BIC95300B claims a "Max On Resistance (at 10amps) of 0.001ohms". I have to admit to not really knowing what that means in a real world way.

Kind regards, Josh

The BICs use the SSRs as the transfer mechanism so the stats apply to both. The only unknown is which SSR is used in which BIC, there are some that are obvious from the spec and some that arn't.

A claim of "Max On Resistance (at 10amps) of 0.001ohms" is misleading because resistance doesn't change with current, given a resistance the voltage drop is what changes with current. All of their relays have resistance in the single digit milli-ohm range so for currents the volt drop is negligible, for really high currents it can start to add up quickly. If you are going to be pulling high currents through the combiner (charging doesn't count) then you'll be better with a solenoid type device.

Rob

 

[goodtimes]

That being said, I have never had to start the vehicle with a dead main battery off the house battery.

And you don't want to either....not through the Hellroaring BIC.

You will be lucky if you manage to keep the smoke in by trying such a feat...unless you are pulling less than 150 amps through the combiner.

 

[Jonathan Hanson]

$10000 KTM? $3000 used KLR 650

Kevin, did you miss our new project vehicle? A $3,000 used DR650.

To address your main question: Absolutely nothing wrong with a manual switch, as we said. However, it's an alternative to an automatic system, and difficult to compare directly using the same parameters. Like a kinetic rope is an alternative to a winch, but difficult to compare directly.

As to that high-end gear, trust me that each one of us is frugal in the extreme. We have simply found, time and time again, that the best equipment is the cheapest in the long run, and worth saving for. Yes, sometimes we step beyond pure function into style (i.e. the J.W. Hulme in the duffel review), but we'd never compromise function for style.

Also, we will never knowingly feature a product that was copied from the original designer/manufacturer and reverse-engineered to be produced at a lower cost. Thus no $200 oriental clones of Warn winches in that review.

Action Packers versus Zarges? Fair one.

Ice chest versus Engel? Fair too, but ice costs money, and ties you to sources.

$100 Walmart tent? Not likely. Too much personal experience with cheap tents when I was guiding.

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