LIFEPO4 Battery discussion thread

TheChamp said:
I have a suspicion the fridge gets very close to the max 100A at startup, not very efficient so there is a slight dimming of lights when it kicks in, with the TVs and lights, the 200Ah is the comfortable choice.
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Yes, but it takes a few seconds to trip a bms so it should be over before it even cares. I've seen people start cars with 100Ah.
 
TheChamp said:
I have a suspicion the fridge gets very close to the max 100A at startup, not very efficient so there is a slight dimming of lights when it kicks in, with the TVs and lights, the 200Ah is the comfortable choice.
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The BMS is the issue, not the actual battery.... if the 200A battery has the same BMS in as the 100A battery then you will have the same problem. The BMS is what limits the AMP draw, the battery size has nothing to do with it. Usually a bigger battery should have a bigger/better BMS in to handle more amp draw, but you need to confirm that with the supplier.
 
irBosOtter said:
The BMS is the issue, not the actual battery.... if the 200A battery has the same BMS in as the 100A battery then you will have the same problem. The BMS is what limits the AMP draw, the battery size has nothing to do with it. Usually a bigger battery should have a bigger/better BMS in to handle more amp draw, but you need to confirm that with the supplier.
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I challenge you to find a 100A bms that cuts out from overcurrent in 0.3 seconds.
 
wingnut771 said:
I challenge you to find a bms that cuts out from overcurrent in 0.3 seconds.
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WTF has that to do with typed?
I have seen an el cheapo 200A battery that had a max draw of 80A due to the BMS it had. I don''t give a F what it trips out on, just informing one has to make sure if is says 200A on the battery also make sure the BMS can do 200A, that's all.
 
irBosOtter said:
WTF has that to do with typed?
I have seen an el cheapo 200A battery that had a max draw of 80A due to the BMS it had. I don''t give a F what it trips out on, just informing one has to make sure if is says 200A on the battery also make sure the BMS can do 200A, that's all.
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You don't think the 80A bms can start a fridge?
 
TheChamp said:
To add I am looking at better brands so that I am able to add on, need it for a small system for fridge, lights and TV.
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Wonder if Geewiz will have another black Friday deal like they did 2 years ago where it was 50% off on some. People on the 4x4 forum have installed those 100ah and 300ah batteries in their 4x4's, and still no complaints from any of them, one would think driving thousands of km's on dirt roads would rattle the hell out of them but they seem to hold up. The 100ah one I got from them also had many trips on dirt roads and also no issues so far. Still giving me just over 100ah of actual usage, the test sheet that came with it showed 104ah
 
irBosOtter said:
Wonder if Geewiz will have another black Friday deal like they did 2 years ago where it was 50% off on some. People on the 4x4 forum have installed those 100ah and 300ah batteries in their 4x4's, and still no complaints from any of them, one would think driving thousands of km's on dirt roads would rattle the hell out of them but they seem to hold up. The 100ah one I got from them also had many trips on dirt roads and also no issues so far. Still giving me just over 100ah of actual usage, the test sheet that came with it showed 104ah
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Lithium batteries are proving to be very reliable, even the unbranded ones, I bought some no name ones some years ago, much to the amusement of some on the forum.

They are still working and holding charge like a boss.
 
TheChamp said:
Lithium batteries are proving to be very reliable, even the unbranded ones, I bought some no name ones some years ago, much to the amusement of some on the forum.

They are still working and holding charge like a boss.
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My scott ones are also fine. Been using shitty pulse lead acid chargers on them too, even charges to 15V.
 
Only issues reported there was the one guy that built his own one, the cells had swollen quite a bit over 4 years, but as he explains:
"My issue is that I overcharged the battery. I only had a fridge in my car for maybe 2 months in a year. The rest of the time the WRND charger took it to 14.4V every day. I should have disconnected the WRND while the fridge was out"

I leave mine on 40-50% when not using it

https://www.4x4community.co.za/foru...build-own-LiFePo-battery-to-replace-AGM/page4


Got a bit lazy to use the Victron app on my phone to check the status from the shunt so built a ESP32 unit to receive the data via Bluetooth (probably have to say Claude AI did all the hard work for me, I did nothing really haha)
 

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