That is a 4Ahr battery, which is probably the reason it looks relatively cheap compared to larger capacity ones.
The 100 amp rating might be for the non plus model. We purchased the Plus model. From the plus model with the 200 amp BMS:Looking at the Ampere Time specs, those have max charge/discharge of 100A, so perhaps this 0.5C rating is common among dropins.
For comparison, the higher quality cells used to build batteries have 1C charge and 2C discharge ratings.
Yes, those sound more usual. Likely they are the same battery cells with different BMS's. Those temps are just what is required of the chemistry like you say. If you need to charge in lower temps, make the battery warmer with heat pads. The upper temp shouldn't be a concern unless you need to put the batteries in a very hot compartment.The 100 amp rating might be for the non plus model. We purchased the Plus model. From the plus model with the 200 amp BMS:
recommend charge current 40 amps
max continuous charge current 200 amps
max continuous discharge current 200 amps
max discharge current for 5 seconds 400 amps
cycle life 4000 times
What I don't like are the operating temps 0-50C charge -20 to 60C discharge and storage temps of -10C to 50C but that is due to the chemistry.
why would there be a problemI was thinking of using this on my LifePo batteries. Anbody see a problem? View attachment 145415
No, those are common fuses used in LFP systems. The main fuse to the battery would be better to be a class-T fuse for interrupt current rating. Otherwise, those MRBF fuses are great branch circuit fuses.I was thinking of using this on my LifePo batteries. Anbody see a problem? View attachment 145415
I'm assuming the batteries are wire in parallel. In our case the MPPT controller is limited to 40 amps, the DC to DC is limited to 20 amps (didn't want to overload the alternator) and the inverter charger can do 100 amps but is settable in 5 amp steps. So even if all three devices are pumping in amps the BMS limit is not reached in our application. The alternator is always connected to the lead acid battery so it is never unloaded.So how do the max charge currents work when a BMS drops out a drop in battery? Lets say you have 3 batteries that can accept 50A each and your alternator + solar could do 120A. When the batteries are charged 1 of the batteries BMS drops it out and now there are only 2 50A acceptance batteries on line with a 120A supply. What if another battery drops out????
So users just ASSUME that is what will happen? All batteries will be so close that they all go off line at same time and therefore don't experience the over spec charge rate?For the case you stated the battery voltages track each other very closely within 10's of millivolts so the case of having 2 batteries charge completely then the entire 120 amps flows into the one battery won't happen because the current will decrease as the battery voltages rise. Which is way it is recommended NOT to mix old LiFePO4 with new ones.
In this case, I think not because the batteries BMS would shut the battery off from the alternator if it tried to deliver too much current. And the amount of current allowed is multiplied by the number of batteries in parallel (to an extent). Since you are looking at 5 of these, that would be a maximum of 450A of charging current allowed (nominally).I am not interested in "debate" really. What I read that as is it comes down to faith. My alternator would easily overcharge a single battery in my example since LFP acceptance resistance doesn't limit current.
Well, I don't run my alternator at full blast now and have it belt reduced to 70% plus have a temp sensor.Your main concern would be burning up your alternator from running full blast continually.
Looking at the price of the 3.6V individual cells I can't really believe the price of those drop in batteries.I saw some to me unbelievable low priced 100Ah drop in LFP batteries on Amazon today (Amazon.com). At least low priced to me who got my last set of batteries only 2 years ago and was comparing costs of LFP to the FireFly batteries I got. Now I read Rod's article slowly this morning:
Drop-In LiFePo4- Be an Educated ConsumerLead is Dead (almost) Warning: This article is long and detailed. It may require two reads so the nuances and detail are not missed. You may be wondering why I am saying lead is dead ?The answer to that is simple; lead acid battery makers dug their own gravesmarinehowto.com
and chased down the full spec sheet attached.
To my reading this seems a good LFP battery spec compared to the items Rod's article