Japanese RV Build— Stuck on Bulk / Configuration Review

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coleinavan asked Dec 9, '20

Japanese RV Build— Stuck on Bulk / Configuration Review

Hey Folks,

Appreciate you stopping by. I’m new to this area, but I’ve done a bit of research to solution for various other issues.. That said, i now am a bit stumped and would appreciate some help.

Background on my set up:

180w NewPowa solar panel x2 (Run in parallel & Fully tested before and after install)
Victron MPPT Controler 100| 30
Battle Born LiFePO4 (lithium) 100Ah 12v battery x3 (total 300Ah) run in parallel
Victron BMV 712 Smart Monitor

Configuration for Victron systems:

Pictured below are my key setting configurations for my set up. I used the manual as well as some other threads to determine my settings.

Settings for the 100| 30 Controler :

Settings for the 712 Smart Monitor:

Questions/Concerns:

Based on my Whole electric system, does my configuration above seem to be accurate or are there pieces that I should re-evaluate?
Today and yesterday (during the day) my system has been stuck in ”Bulk”, which from what I read, means that the batteries are low and the system will bring in large amounts of power to charge them. The issue is that the batteries are very close to being fully charged. (below is some data from the app showing that I’m stuck on float) . I think its important to point out that I have been able to put a load on this and see my numbers and battery voltage adjust but I continue to stay in “bulk” . What could be causing this?
Possibly related to #2, today during a sunny day, my solar panels were barely bringing in any watts 30-50w range, while in bulk model. My battery on the monitor was at 95% or 13.4v but it didnt seem like it was going up at all. Any reason why this was happening?

Any help is greatly appreciate. Happy to provide more details around certain aspects.

Here are some additional data grabs...

Below is a picture from the monitor today while having a slight load on it (fan, heater, lights):

Here’s a picture of the van when I bought it.. It’s changed a lottttt since then.

MPPT Controllers Solar Panel solar

03c5be38-f0a7-4222-8e02-0c56eda7ef55.jpeg (249.4 KiB)

b0765ee9-5540-4b80-b9bc-3bf0d2dd54b7.jpeg (262.7 KiB)

b89319f7-9f4b-4a0f-a9f0-beac7946d78e.jpeg (220.2 KiB)

67429dec-999b-4d2f-a6d0-c011def38ab2.jpeg (235.1 KiB)

ff1fae27-421f-496a-a170-0c6d3f595c11.jpeg (235.1 KiB)

1a441981-cf5b-4e68-81e4-472f972d6c1c.jpeg (235.1 KiB)

6e6b314c-43e3-4801-a52d-35ee3b2e2c93.jpeg (220.2 KiB)

ee15ecb2-3914-4e3d-8c33-fca864a249e2.jpeg (2.4 MiB)

1f34d514-ab1b-4cc8-ad3f-d43a0a3bc3f9.jpeg (220.8 KiB)

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

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Answer 1 · 2020-12-09T04:14:25Z

klim8skeptic answered · Dec 09, 2020 at 04:14 AM

Your panels Vmp/Voc are too low.

You could wire them in series.

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coleinavan commented · Dec 09, 2020 at 04:34 AM

Thanks for the input! Could you elaborate a bit more on this? I’m a bit confused because ive read multiple builds using a very, if not exact, same set up while running the same panels in parallel. I spent some time digging to eventually decide on parallel, so if i need to switch, the more info the better! Thanks again

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Answer 2 · 2020-12-09T07:17:38Z

dgnevans answered · Dec 09, 2020 at 07:17 AM

From the settings above there are one or 2 settings on your mppt that dont appear to be correct. For the setup of your Mppt and BMV refer to these pages from Battle born.
https://battlebornbatteries.com/programming-a-victron-smartsolar-charge-controller/
https://battlebornbatteries.com/configure-victron-bmv-700-bluetooth-dongle/
You should connect your panels in series, you need to be careful that you VOC does not exceed the input voltage allowed for the mppt. which in your case with the above panles and mppt you will be fine. Mppt has input volatge of max 100vdc.
The reason to go in series instead of parallel, you are increasing the voltage of the system but keeping the current at the same level. this means it is more efficient and you have less losses. your system will also start charging earlier and finish charging later in the day.

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coleinavan commented · Dec 09, 2020 at 02:29 PM

Hey Dgnevans, I appreciate the links. I have adjust my settings accordingly.

To the solar panels... What you are saying makes sense.. I’m just confused why there was so much guidance online for me to run these panels with this set up in parallel and not series. My understanding was that in lower sun conditions (much like what I will be experiencing in the winter since I chase snow) it would be a better idea to do parallel.. I also have a fan on my roof that sits up against one of my panels which could cause Partial shading. Are these things that should be considered before switching to series? Or is it a no brained that i switch to series? Apologies for all the questions, its just going to be a bit of a process to switch to series given how i have it wired today, so I want to make sure I cross my ’t’s and dot my ‘i’s before going down that road.

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coleinavan coleinavan commented · Dec 09, 2020 at 04:24 PM

Quick update; I just went out and the sun was beaming on my two panels. My control was still only ready around 180w ... I have 380w system. I dont expect to get to 380w but is there a chance a panel is not operating to its full potential? Or is this all to do with the fact it is run in parallel and not series?

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e09f4b8d-ba11-4e89-b075-06958e64c071.jpeg (191.4 KiB)

jvan coleinavan commented · Mar 31, 2021 at 07:57 PM

Hey @Coleinavan, I have the same dilemma. Do you have any updates on how you moved forward? Did you end up rewiring for series? Or did you stay in parallel and go with a different brand of solar panel with a higher Vmp? Thanks!

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Answer 3 · 2020-12-10T00:25:20Z

michelg answered · Dec 10, 2020 at 12:25 AM

Hi ! according to the specs of your panels, the voltage is really too low. The MPPT needs at least 5VDC over the battery voltage... So, the best way to go is connecting the panels in serie, to get a 33-35VDC. Also, you won't get too much power as they are installed probably in a "flat" way, so the angle to the sun is not optimized and only a short part of the sun is absorbed by the PV panels. If you have the opportunity to add 2 other panels, also in serie, and then both arrays in parallel to your MPPT, you will get around 350Wp of power.

screenshot-www-ebay-com-itm-180-watts-180w-newpowa.png (67.1 KiB)

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coleinavan commented · Dec 10, 2020 at 03:50 AM

Thanks for this! Let me just play this back to make sure I follow. My current set up is not kicking on my controler properly and charging my lithium battery cell because my panels are wired in parallel which means they only get up to 16.77 vmp and the controler requires my battery voltage +5...

Is that correct?

If so, few questions, why has my solar voltage gone to just under 18 on the victron app? And does this mean I absolutely have to run in series to get any charge?

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72b72fac-bcc5-4d67-8232-860427359946.jpeg (191.4 KiB)

Answer 4 · 2022-02-13T03:53:49Z

@Coleinavan The solar voltage is showing open circuit voltage because the charging has stopped. The controller senses the battery is fully charged because it has reached the voltage you set in the bulk/absorption setting.

This could be the result of the wiring being too small/to long between the MPPT controller and the battery, or a bad choice of fuse type or a poor connection. Do not use blade type fuses in any solar circuit, these are renowned for high resistance joints. Look for a midi fuse holder and relevant capacity fuse on E Bay etc.

Next, have you set up a network in you BMV and then linked the MPPT controller to that network. This will send the true battery voltage to the MPPT controller and allow it to better control the output voltage and push more current into your battery pack.

Your next real problem will be with the wiring between the 3 x drop in batteries, this can be an absolute headache and this is why multiple 12v lithium batteries should not be used to build capacity .... unless each battery can actually link each cell to the other matching cell in the other parallel batteries in the group, or, each battery actually monitors the cell voltages rather than the over all battery voltage and can turn that battery off while the cells in that battery rebalance ......

Lithium batteries have extremely low internal resistance, this will result in one battery doing all the work and dieing an early death, then killing the other batteries in parallel.

To get an idea of what I mean, check out tjhs web site http://www.smartgauge.co.uk/batt_con.html Hopefully it will open at this page

How to correctly interconnect multiple batteries to form one larger bank.

I am not at all associated with this site and I don't actually use any of their products, but the info is often worth the read

T1 Terry

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