-
Join the MyBroadband community
South Africa’s biggest forum. Discuss, discover, and connect with thousands of members.
-
Question of the Day: How do you normally pay for purchases in stores?
Will a normal SLA charger damage a lithium battery?
- Thread starter BrandonJ
- Start date
wingnut771
Honorary Master
Yes, if its 14.6V or less. No it won't damage the battery.
Lets assume the battery is not heavily cycled, and frequently reaches the chargers float charging mode.
Does a lithium battery need to be float charged, and what is the consequence of keeping a lithium battery at 100% SOC?
Geoff.D
Honorary Master
Is this an "in an emergency" type of question? If you can spend the money buying a Lithium battery, why take a shortcut and not have the correct charger as well?
If a normal charger won't damage the battery, and will charge it at the correct curve, why spend money on a different charger?
wingnut771
Honorary Master
Lithium doesn't need to be floated, so when the charger is in float mode, the battery is already fully absorbed and there won't be any amps flowing and is just at a slightly higher voltage than resting so it will be fine. They don't like sitting at high voltage like 14.6V. So it's more about the voltage than the SOC.
wingnut771
Honorary Master
Try find a lithium charger.
If I understand correctly, high voltage for a lithium ion battery would be about 4.1V/Cell. (you cannot state it as 14.6V) At 4.2V/Cell cycle life would be around 300-500, at 4.1V/Cell it rises to 600-1000 at 4V/Cell it rises to 1200 - 2000 cycles.
This is a function of keeping the battery at high voltage, or high percentage SOC. Lithiums don't like 100% SOC and this is clearly observed by the decrease in cycle life at higher voltages.
In the example of the battery above, which is not heavily cycled - how is the float charge function of the charger acting upon the battery? i.e what is the purpose of the float charge function?
Last edited:
We have a wide range of chargers in stock, that are compatible with Lithium batteries, namely Meanwell ENC from 1A to 16A, and All the varieties of Victron Chargers.
They are not really that hard to find.
wingnut771
Honorary Master
LFP is 3.2V nominal (12.8V), 2.5V min, 3.65V max. So 3.65x4=14.6V
You are thinking of NMC which is 3.7V nominal.
wingnut771
Honorary Master
There is no purpose with lithium as it has a very slow discharge rate. It is there because its a lead acid charger.
wingnut771
Honorary Master
link?
For some reason the forum doesn't seem to like my links , I will attach a catalog for you later.
Ok, 4.2V/cell represents 100% SOC. But it's not relevant at this stage.
By no purpose, do you mean it just disengages and doesn't apply a float, or it does apply the float but it's not needed?
wingnut771
Honorary Master
4.2V is NMC
Lead acid replacements use LFP (LiFePO4).
LFP 100% SOC is anywhere from 13.6-14.6V (3.4V-3.65V per cell).
wingnut771
Honorary Master
It applies the voltage but no current flows because LFP doesn't discharge like LA does.
So it float chargers or keeps the battery at 100% SOC, or the battery remains at 100% SOC - allowing for a very slight self discharge?
Koosvanwyk
Expert Member
- Joined
- Aug 6, 2015
- Messages
- 1,157
- Reaction score
- 645
48v?
wingnut771
Honorary Master
The charger will hold the voltage at float voltage and because the battery is 100% SOC (fully absorbed) it does nothing. Maybe after a month some current will flow in:
