Bely 12V 150AH LiFePO4 battery with Bluetooth, low temp cut-off and heating

rickst29

Solar Enthusiast
Looks great, an all-in one battery for only a small price premium above unheated batteries WITHOUT bluetooth monitor capability. Great performance as well, for batteries advertised at 150 Ah.

My own situation, unfortunately, calls for a DIY warming "solution". I already have 2 non-heated LFP batteries, and I want to warm them with "12v" motorcyle-seat heating pads allowing charge voltage to be present. With the 3rd (new DIY) battery, I could put similar things in the case - but I'd still need a lot of additional Relays to control charging versus heating on the two dumb batteries. I'm inclined to make the "Charge versus Heat" decision completely external (but within the battery storage compartment of my RV) directing Converter output to either charge the batteries OR run the heater - and never both.

With the Solar Charge Controller, unfortunately, my scheme can't make that automatic choice for all 3 batteries at once. The SCC which I have does provide distinct "input power" ports versus "Charging Output ports, it simply has a pair of connections to the battery bank. In mornings, before Solar becomes active, I could add a timer relay to make the batteries warm themselves (before significant solar power becomes available). The temperature Sensor would be downstream from that, enabling heat only within the range of "heater control" operating characteristics.

In my scenario with OUTSIDE heater pads, the compartment becomes warm before the battery cores have reached adequate temperature. So I am thinking, maybe 3 degrees C to turn on the warming pads (around 38F), but leave them running until the compartment reaches 15 degrees (around 12C, or 50F).
- - -
Now to my point: Your batteries, even though the small cells are relatively thin, have some of the same effect: the warmed case temperature might be considerably higher than the core cell temperature, and 40F might not be high enough (at the temp Sensor) to assure that the battery is entirely ready to accept charge current. (I'm going to a higher temperature.) Do you think that 40F at the top of the case as sufficient? And if not, can you modify that figure from the cellphone/bluetooth interface?
 

Mako74

Solar Enthusiast
Looks great, an all-in one battery for only a small price premium above unheated batteries WITHOUT bluetooth monitor capability. Great performance as well, for batteries advertised at 150 Ah.

My own situation, unfortunately, calls for a DIY warming "solution". I already have 2 non-heated LFP batteries, and I want to warm them with "12v" motorcyle-seat heating pads allowing charge voltage to be present. With the 3rd (new DIY) battery, I could put similar things in the case - but I'd still need a lot of additional Relays to control charging versus heating on the two dumb batteries. I'm inclined to make the "Charge versus Heat" decision completely external (but within the battery storage compartment of my RV) directing Converter output to either charge the batteries OR run the heater - and never both.

With the Solar Charge Controller, unfortunately, my scheme can't make that automatic choice for all 3 batteries at once. The SCC which I have does provide distinct "input power" ports versus "Charging Output ports, it simply has a pair of connections to the battery bank. In mornings, before Solar becomes active, I could add a timer relay to make the batteries warm themselves (before significant solar power becomes available). The temperature Sensor would be downstream from that, enabling heat only within the range of "heater control" operating characteristics.

In my scenario with OUTSIDE heater pads, the compartment becomes warm before the battery cores have reached adequate temperature. So I am thinking, maybe 3 degrees C to turn on the warming pads (around 38F), but leave them running until the compartment reaches 15 degrees (around 12C, or 50F).
- - -
Now to my point: Your batteries, even though the small cells are relatively thin, have some of the same effect: the warmed case temperature might be considerably higher than the core cell temperature, and 40F might not be high enough (at the temp Sensor) to assure that the battery is entirely ready to accept charge current. (I'm going to a higher temperature.) Do you think that 40F at the top of the case as sufficient? And if not, can you modify that figure from the cellphone/bluetooth interface?
@rickst29, I appreciate your feedback and you've made me think about your point regarding the 5°C threshold for charging to begin. I will find out what Bely thinks of this.
 
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