Why isn't Solar charging showing on BMV-712?

Question

question

jdalaska asked Jun 11, '20

Why isn't Solar charging showing on BMV-712?

I've had the BMV-712 monitoring 2-100AmpHour AGM batteries in my motorhome for about 2 years. When connected to shore power, it charges the batteries and shows INFINITE for time remaining. When disconnected from Shore Power, it shows 12 +/- days remaining and slowly drains showing depleting battery charge and reduced days remaining. That's all great.

Recently, I added 4-100 Watt solar panels and a ZAMP-30 Controller wired to the Batteries.

The BMV-712 does not show any charge input or accumulation from the solar panels and shows declining battery state and days remaining, even though the ZAMP Controller shows that my Batteries are full.

I assume the Solar contribution is not being seen by the BMV, but am not sure how to rewire the setup.

Any help would be greatly appreciated.

Solar Panel

2 |3000

Attachments: Up to 8 attachments (including images) can be used with a maximum of 190.8 MiB each and 286.6 MiB total.

Modifications Space

Node Red Space

Answer 1 · 2020-06-11T05:53:57Z

mvader (Victron Energy) answered · Jun 11, 2020 at 05:53 AM

Hi jdalaska, please check the BMV-712 manual on our website. It has a section of common wiring mistakes and this one is in them (solar is wired directly to battery while it should be on the “System” side of the shunt).

Have a good day!

3

2 |3000

Attachments: Up to 8 attachments (including images) can be used with a maximum of 190.8 MiB each and 286.6 MiB total.

jdalaska commented · Jun 11, 2020 at 07:09 PM

Thank you, Mvader!!

The "installer" whilst RV savvy, was unfamiliar with your product and wired the solar panel (-) directly to the battery as you surmised (I did not catch this, as the initial focus was on Solar Performance).

I rerouted the Solar (-) to the System Side of the shunt and voila. My 712 appears to now be reading the total current used/added. A few days observation will confirm this, but initial indications are that the problem is solved.

Thanks again, for monitoring this forum, and for providing useful and timely information. You likely saved me a few $$ for a 10 minute re-route of wires.

PS. While profoundly deep in theory and EE systemology, I find the Manual to be a bit vague for the "lay user". Section 2.3 "Common Problems" on page 10 has the only reference to Solar that I was able to find, and it does not address wiring or the shunt. While it now seems logical that the solar connection needs to be on the system side of the shunt, I don't see reference to that in the Manual or the Quick Installation Guide.

But this forum provided the clarity I needed. Thanks again.

0 ·

mvader (Victron Energy) ♦♦ jdalaska commented · Jun 12, 2020 at 04:15 AM

Hi @jdalaska, you're welcome! I'm glad it works good now.

As you've read the manual so closely, can I ask you to read this one too? Also it has an improved quick install guide:

https://www.victronenergy.com/battery-monitors/smart-battery-shunt

Its been totally rewritten and then plan is now to redo the BMV-712 in the same format.

Its quite a challenge to write to a in lay user when fully embedded into the matter.

0 ·

jdalaska commented · Jun 21, 2020 at 11:10 PM

I have read through the Smart Shunt manual and Quick Install Guide as you invited and believe it to be improved as compared to the existing 700-712 Manual/Guide.

For what it is worth, I earned a BSEE degree in 1979, but never worked in that field (I was a military/commercial Pilot for 40 years). I consider myself a competent electric hobbyist, but nothing beyond household/RV tinkering.

While I suspect your product line caters more to industrial applications, the BMV series and now the Smart Shunt are Ideal modifications for RVs due to the large dependency on Batteries and the ability to monitor them. I appreciate the value these products bring to the RV market.

From the Recreational User's standpoint, the single most important paragraph I found in the new manual is 3.3.2. I would repeat that message in the Quick Installation Guide as well, since that is quite possibly the ONLY resource that many non-engineers will utilize when connecting their battery monitor.

I look forward to learning about your future products and manuals. Regards from the US PacificNorthwest.

JD D

0 ·

question