Those of us running Lithium batteries should be aware that charging them below freezing is not advisable and may cause damage to the battery. Most lithium batteries that have an on-board battery management system (BMS) already have a low-temperature lock out to prevent charging below freezing.
To maintain charging function below freezing, I upgraded to a self-heating battery by Renogy this fall. This battery will heat itself while being charged as long as 4 amps are being supplied to the battery. If a minimum 4 amps of charging current are unavailable and the battery is below 32F, it won't heat or charge (discharge is allowed to a much lower temp).
I took the battery on a couple trips and noticed it was not charging at times even when the engine was running, which should have supplied 25A through the Redarc BCDC I have supplying the battery. This should have been plenty to engage the self-heating and begin charging the battery. After looking through the documentation, I thought perhaps a combination of a temperature-compensating alternator and cold starter battery could be putting the main 12V rail below the cut-off voltage for the BCDC to activate. Measurements showed that was not the case.
Eventually I stumbled upon a blog post explaining that the BCDC also has a low-temperature lock out below freezing when set to lithium mode. This feature is not included in the printed or online manual for the BCDC. BCDC Updated Features Explained | REDARC Electronics - https://www.redarc.com.au/faqs/updated-bcdc-features-explained
My fix for a self-heating lithium battery charging from a BCDC (disclaimer: consult your battery manufacturer and documentation to replicate at your own risk!) is to cut the Orange:Green wire connection, changing from the "Li" profile to the "A" profile. The "Li" and "A" profiles are very similar and the "A" profile still fit entirely within my battery spec. The "A" profile does not include the same under-temp protection that the "Li" profile has.
The battery now engages self-heating and charges in below freezing conditions!
Hope this helps someone!
To maintain charging function below freezing, I upgraded to a self-heating battery by Renogy this fall. This battery will heat itself while being charged as long as 4 amps are being supplied to the battery. If a minimum 4 amps of charging current are unavailable and the battery is below 32F, it won't heat or charge (discharge is allowed to a much lower temp).
I took the battery on a couple trips and noticed it was not charging at times even when the engine was running, which should have supplied 25A through the Redarc BCDC I have supplying the battery. This should have been plenty to engage the self-heating and begin charging the battery. After looking through the documentation, I thought perhaps a combination of a temperature-compensating alternator and cold starter battery could be putting the main 12V rail below the cut-off voltage for the BCDC to activate. Measurements showed that was not the case.
Eventually I stumbled upon a blog post explaining that the BCDC also has a low-temperature lock out below freezing when set to lithium mode. This feature is not included in the printed or online manual for the BCDC. BCDC Updated Features Explained | REDARC Electronics - https://www.redarc.com.au/faqs/updated-bcdc-features-explained
My fix for a self-heating lithium battery charging from a BCDC (disclaimer: consult your battery manufacturer and documentation to replicate at your own risk!) is to cut the Orange:Green wire connection, changing from the "Li" profile to the "A" profile. The "Li" and "A" profiles are very similar and the "A" profile still fit entirely within my battery spec. The "A" profile does not include the same under-temp protection that the "Li" profile has.
The battery now engages self-heating and charges in below freezing conditions!
Hope this helps someone!
