I’m going to switch over one of my solar Meshtastic nodes over to a LiFePo4 cell instead of dual 18650’s and I think I ran into a snag.
I’m using the waveshare solar manager model D
But I realized looking at the stats it has an over discard voltage cutoff at 3.0v and these cells are 3.2v
Would I be fine running this charge controller? Seems like a pretty narrow band to cutoff charging.
So LiFePO4 batteries have a different cell voltage and a different charge curve than standard lithium ion. If I were you I would get a MPPT with a dedicated LiFePO4 charging setting. They’re too far in between lithium ion and sealed lead acid to use either of those charge configurations while maintaining the long term health of the battery. If charged incorrectly they can develop a high internal resistance due to gas adsorption at the electrodes and then you get a runaway heat situation. Especially problematic when they’re always charged in an unsupervised setting.
LiFePo4 cells are working fine between 2.5 (empty) and 3.65V (charging end voltage). I would prefer a dedicaded SolarCharger made for LFP chemistries. They are more robust than LiIon or LiPo batteries, and does not catch fire, if they were overcharged. I use some LFP Batteries to power some projects directly without any buck- or boost converter. LFPs are my favorite cells.
Yeah i was considering picking one of these up.
Its made by the guy that owns Voltaic enclosures. in the Meshtastic community its basically the standard for charge controllers to bypass the 500ma charge circuit on the Rak Wireless nodes. I was only going to use the Waveshare one because i have so many of them. But i guess ill just grab his. wanted an excuse to try out his things anyways, i guess now is the time.
i guess its al about the end use and philosophy really. i have made some projects using solar and low electricity draw electronics like fm and uhf transmitters and have had great luck with some of the cheapest ebay components soldered together and even using Lithium Polymer pouch type batteries.
then again when i did the electricity for my diy campervan i spaired no expense victron, battle bourn ect.
are you realistically needing it to function for 5 years without maintenance?
would you be happier with 2 or 3 cheaper but still effective meshtastic nodes?
there are no wrong answers just figured share my thoughts on the philosophy of project management
