Charging 12v Lithium Batteries.

[PPrep]

This is a heads - up about the risk of damaging some cheap charge controllers when charging lithium batteries.

I bought a couple of 12v LiFePO batteries some time ago. At first was mystified in that there was no trickle effect as in fully charged lead acid batteries, but the charge current completely cut off when the lithium batteries were full. I was using a clunky but highly reliable old home-made analogue charger.

In 12 or 24 volt solar charges systems, I've discovered that cheap charge controllers may fail if the battery is not connected before connecting the solar panel (not the hard way, fortunately!). In any case it's better to lay the solar panel face on the ground or away from the sun before connecting it to avoid surges, if possible. This might not apply to solar generators, as they're integrated. All the same, it may be worth checking.

12 volt lithium batteries have a battery management system (BMS) inside to apply balancing to the four cells, and over and under voltage and low temperature protection. When the battery is charged, the BMS will as a rule effectively disconnect the battery from the solar panel, so endangering some charge controllers. High - end controllers such as Victron are largely immune to this problem. Although there's a lot of debate about this, the only safe way to be sure is to carefully check the manual for the particular make and model of charge controller that you use.

Lithium batteries will outlast lead - acid batteries as a rule. Lithium batteries can safely be discharged to 85%; maximum safe discharge is about 65% for lead acid. Not exceeding these limits will help maximise the life of the battery. Lead - acid batteries like to be kept topped up; lithiums are best stored at about 60 to 70% full charge.

It seems possible to charge a lithium battery from solar panels without a charge controller. This is not recommended as if the BMS malfunctions, the battery could overcharge. Note that lithium batteries are prone to catch fire if abused.

Lithium batteries are likely to be as vulnerable to a coronal mass ejection or electromatic pulse as general electronics because of the BMS inside the case. These are normally sealed in.

[Yorkshire Andy]

You've managed to post twice no bother I'll shut this one. And leave the other open for replies

https://www.uk-preppers.co.uk/forum/vie ... hp?t=19089