photo sharing and upload picture albums photo forums search pictures popular photos photography help login
Compass Marine How To | all galleries >> Welcome To >> LiFePO4 Batteries - Thoughts & Musings > Laying Out The BMS
previous | next

Laying Out The BMS

For the BMS on this bank I chose to use the simple and cost effective EDIT: Has Closed It's Doors to DIY's from Clean Power Auto.

There are fancier and significantly more expensive BMS products out there but very few are geared towards off-grid or house bank use and usually offer more features and complexity than may be useful on a boat. Elithion and many other companies make BMS systems and there are enough to make your head spin. Genasun also used to make a beautiful BMS, they sold to DIY's, but like Clean Power Auto they have since pulled out of the DIY market.

Are we starting to see a trend here? I no longer consult long distance on LFP design because owners refused to follow design criteria, Genasun stopped Selling to DIY's and then dropped LPF altogether, and now Clean Power Auto has pulled out of the DIY space. If you've done your research I suspect you know why this trend exists.

If you are still looking to build your own a good company, as an alternative, would be; Orion BMS

The HPBMS is the small PCB in the box. I cut shaped & routed a piece of high density phenolic to fit inside the Velleman box so the layout of the BMS could be done outside the box then simply dropped into it.

Additional items shown:

#1 Two 70A Cole Hersee RC-700112-DN SPDT 70A Relays. One for Alternator HVC and one for Solar HVC. (Ignore the relays in this image they were for layout and mock up only and are SPST not SPDT)

#2 Blue Sea Terminal Strip

#3 Piezo alarm buzzer 12V.

#4 Momentary re-set switch.

other sizes: small medium large original auto
Jim Kevern 27-May-2016 19:01
There are two different types of contactors in the Tyco EV200 line, some with and some without an "economizer". The ones with the economizer drop the current back after the contactor is closed to something like 130 mA.
elizabeth ferguson 11-Feb-2015 20:40
Is this still Technomadia? It looks like this may have been linked. Anyhow, if this is still Chris, is it possible that part of the reason you Lithium batteries are not lasting as long as you expected is because there are too many solar panels or not enough batteries? Accoring to this article your battery life can be shortened by overcharging. This is an excellent piece but since it said the focus is on boats and I nearly didn't read it.
Chris 25-Aug-2014 10:12
HousePower recommend a Tyco EV200 contactor for this BMS.

The EV200 consumes about an amp to keep it latched. This seems like a large overhead drain on the system. What is the alternative? Can we use a NC contactor rather than the NO poles (would that require re-programming the BMS)?