BMV-700

Jon W · November 20, 2015, 06:33:52 PM

Is the BMV-700 the same as the Xantrex LinkLite except that the Xantrex LinkLite can also measure voltage only of a second battery?

Jon W.

mainesail · November 21, 2015, 05:04:19 AM

Two different products with similar abilities but not really the "same"... Link-Lite will cost a lot more and lacks a lot of the programming features that the Link-Pro offers such as the ability to program charge efficiency.. Now that the BMV-702 offers temp sensing it is a good value. The BMV-700 and Link-Lite do not offer temp sensing and therefore any temperature compensation that could help identify the most accurate SOC will not be taken into account.

If you desire a level of accuracy out of an Ah counter it takes a good deal of work on the owners part...... If you don't have the capability to capacity test your batteries, to keep the Ah counter accurate, then the Balmar Smart Gauge is a better product for knowing SOC but it does not give you current just voltage and SOC......

FWIW I have a bank on my test bench right now that just delivered 177.6Ah and it is a two year old 225Ah bank. Owner still has the Ah counter programmed for 225Ah.......

If we do some simple math it becomes easy to see that when this owners Ah counter says 50% SOC he is really well below 50% SOC.... You can not remove 112.5Ah's (half of 225Ah) from a 177.6Ah battery and be at 50% SOC..... D'oh....

Programming A Battery Monitor

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Jon W · November 21, 2015, 07:55:45 AM

Thanks for answering. My takeaway is if I don't do the programming steps religiously then the value of these devices is minimal. It does seem measuring amps is important to see if you have any"leaks" in the electrical system. Is there something you recommend for that? Jon W.

mainesail · November 21, 2015, 09:31:17 AM

Quote from: Jon W on November 21, 2015, 07:55:45 AM
Thanks for answering. My takeaway is if I don't do the programming steps religiously then the value of these devices is minimal. It does seem measuring amps is important to see if you have any"leaks" in the electrical system. Is there something you recommend for that? Jon W.

No they still have tremendous value and for less than the price of a simple ammeter and shunt you get a lot more features. Where they fall down is in tracking the SOC of the bank but amps in and out, voltage, Ah's etc. are all very useful things to have. If you want to use it for SOC then this is where they get tougher to keep up with.. I now have a fair number of customers using both a Smart Gauge and an Ah counter which yields the best of both worlds. Hopefully Balmar comes through soon with a Smart Gauge that also measures current....

If you read the link below think about where you would have had your batteries programmed in an Ah counter and remember this is just one short season. Compare where your programming might have been and where the Smart Gauge predicted the SOC.

How to Murder Batteries in Half a Year

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Jon W · November 21, 2015, 01:12:01 PM

Hi Maine Sail,
Thanks for the responses and link to an interesting situation. As you have seen in my other post, I'm preparing for a massive upgrade to batteries, charging, wiring, monitoring systems on my 1987.

Is the following correct -
Your recommendation would be the SmartGauge paired with the BMV-700. Let the SmartGauge handle SOC of the house and reserve bank, and use the BMV-700 to provide info on the house bank for amp draw, total amps consumed, and forget about time left. The BMV-700 would then be only an amp counter?

Jon W.

Stu Jackson · November 21, 2015, 05:39:57 PM

Jon,you only need a BVM (BMV?) 600 to do that. I thought I covered that earlier in your wiring missive. http://c34.org/bbs/index.php/topic,8708.msg62167.html#msg62167

Jon W · November 21, 2015, 06:34:09 PM

Yes there is some dulpication, and I suspect I am going back and forth as I learn in real time (in public no less). All part of my inexperience with complex concepts. At least for me.

In the other thread I was asking whether the Blue Sea DC Multimeter was redundant to the SmartGauge because both read voltage. Two voltage displays, which one is right? I'm listing parts now and close to buying, so here I was asking the difference between LinkLite and BMV-700. Cost being the primary driver.

Thanks.

Jon W.

Stu Jackson · November 21, 2015, 09:23:10 PM

Quote from: Jon W on November 21, 2015, 06:34:09 PM...so here I was asking the difference between LinkLite and BMV-700. Cost being the primary driver.

Jon, before you go out to buy something, and even before pricing things, we're always here to help. The Link Lite is way old technology, and the Elec 101 topic with Maine Sail's How to Wire a Battery Monitor discusses the advantages of the Victron over the Link Lite or even Link Pro. That's why I'm confused, 'cuz I thought you'd read it. And the Victron 600 is all you'd need, 'cuz it gives you cc on the house bank and voltage on the reserve bank, which is usually all you need. If you want to spend the extra $$ on a cc for the reserve bank, have at it, but most of us don't feel it's necessary, nor even worthwhile.

mainesail · November 22, 2015, 04:00:15 AM

Quote from: Stu Jackson on November 21, 2015, 09:23:10 PM
Quote from: Jon W on November 21, 2015, 06:34:09 PM...so here I was asking the difference between LinkLite and BMV-700. Cost being the primary driver.

Jon, before you go out to buy something, and even before pricing things, we're always here to help. The Link Lite is way old technology, and the Elec 101 topic with Maine Sail's How to Wire a Battery Monitor discusses the advantages of the Victron over the Link Lite or even Link Pro. That's why I'm confused, 'cuz I thought you'd read it. And the Victron 600 is all you'd need, 'cuz it gives you cc on the house bank and voltage on the reserve bank, which is usually all you need. If you want to spend the extra $$ on a cc for the reserve bank, have at it, but most of us don't feel it's necessary, nor even worthwhile.

Stu,

The Victrons are really not better than the Links, the Link-Pro is really one of the best in terms of programmability, they just represent a better value and are easier to install.

The BMV-600 & 602 were replaced by the BMV-700 & 702 about two years ago.

Stu Jackson · November 22, 2015, 07:41:15 AM

Thanks, Maine Sail. Just what my wife keeps sayin' this time of year, "Stu needs to get out shopping more often!!!"

Jon W · November 22, 2015, 09:30:07 AM

Thanks Stu.

I did read the article on how to connect one. I've been going back and forth on LinkLite/LinkPro/BMV-700 or SmartGauge, or both.

If I bought a LinkLite/LinkPro/BMV-700, I only planned to monitor the house bank. I was thinking of using my existing Link 10 to monitor the reserve/start battery since I had it, but it doesn't work right so that idea is out of the plan.

While the cc's advertise they can provide SOC, Maine Sail has been pretty clear it's work to do it right, and then they usually aren't.

A SmartGauge and a BMV-700 seem to provide all the features with better accuracy and lower cost. Well for boat stuff a lower cost.

Jon W.