diy solar

diy solar

Heating Pad Controller

Tuniberger

New Member
Joined
Nov 23, 2021
Messages
1
How to control heating pads ?

in my RV I use a dedicated temp controller, so I have 4 temp sensors in my Battery ( 2x for BMS, 1x Solar Charger, 1x dedicated heater control ( Temp. Relais )).
I Use the Load output with Lighting settings to supply the heating controller on daytime when there could be a charging current. BMS has a working Low temp cutoff , so no risk charging at low temp, but with my Solution I have some problems:
- Temp Relais standby current
- if there is no Sun heating switches on and drains battery
- Heating did´t switch on at night / no charging via alternator ( Solution would be a diode coupler between Solar charge, dc/dc converter and Temp Controller module. )

Is there some Solare charger on the market with better programmable load switch ? Optimal would be Load on when Temp below Limit and Solar panel current detected.
I can use my existing Solar charger for other projects, so If someone knews a product ( victron ) with better options für heater control I´m willing to change.
Or ist there a BMS on the market witch heating control ?

best regards

Markus
 
Some of the JBD BMS versions have heater control. I have a couple of the long style with the copper bus bars along the sides and they support two heaters with thermocouples. I also have the shorter style with full aluminum heatsink and they have no heater control.
 
Is there some Solare charger on the market with better programmable load switch ? Optimal would be Load on when Temp below Limit and Solar panel current detected.
there are certainly charge controllers which turn only on when there is sun.

You could combine that with just a Bi-metal switch in series. (0 Celsius switch) turn on at 0 and turn off at 5 degree.

Bi Metal switches are awesome for heating and cooling applications. They draw zero current when not in use- usually ideal when then temperature doesn't need to be very accurate.

I use them also for Fans to cool my inverter.
 
One issue with only starting the heating pads when solar starts is if your batteries are cold soaked. It will take a while before the center of the cells rise to 32deg. (Depending on outside temps).
 
One issue with only starting the heating pads when solar starts is if your batteries are cold soaked. It will take a while before the center of the cells rise to 32deg. (Depending on outside temps).
all a matter of sensor placement.

When you put a sensor outside- it will detect cold earlier - so the heater will turn early

And you don't need to start at 32F/0C most low temp heating pads are around 40F 5C

Futher modern LFP cells don't have issues at 0C they starting to get damage at around -20C when you charge them.
 
Back
Top