question

Joka GIMENEZ avatar image
Joka GIMENEZ asked

Best setup for spread battery bank on boat (10m apart) - multiple mppt

Hi!

The batteries on my boat are quite far apart (1 battery - 4m - 2 batteries - 6m - 1 battery).

I'm wondering how to best and evenly charge all batteries to get the longest life out of them.

Due to my panels setup, I am planning on using 3x SmartSolar mppts synchronized with Bluetooth : 2x 75/15 and a third one, ideally 100/20 but could be 75/15 too.

I guess the ideal setup would be to have the 3 panels side by side to a charging bus, then equal distances to each batteries, but it will require quite some cable length!

I was wondering if having 1x 75/15 near each single battery and the 100/20 near the 2x batteries would still be efficient, or if the uneven charge would trigger the absorption cycle too early?


Thanks for your input.

MPPT Controllers
2 |3000
Toggle Comment visibility. Current Visibility: Viewable by all users

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

1 Answer
tozz avatar image
tozz answered ·

You need to route the positive cable to/from your charger/inverter to one side, and the negative cable to the other side. So it would become something like this in series:

[+] - [batt1] -4m- [batt2] - [batt3] - [-]

Or in parallel:

[+]
| - [batt1] - \
| - [batt2] - |
\ - [batt3] - |
             [-]

Where [+] is your positive lead and [-] is your negative lead to your inverter/charger

Do *NOT* do this:

[+]          [-]
| - [batt1] - |
| - [batt2] - |
\ - [batt3] - /

If you do this last diagram, batt1 will do most of the work, and degrade much faster than batt3.

1 comment
2 |3000
Toggle Comment visibility. Current Visibility: Viewable by all users

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

Joka GIMENEZ avatar image Joka GIMENEZ commented ·
Thanks, excellent tip!


Is it important that the positive and negative terminals have the same length? Or can I eventually go with 30cm to positive and 5m to negative?

Cheers!

0 Likes 0 ·