I am changing from 2 6v lead acid batteries in series to 3 100ah group 31 LiFepo4 in parallel. Will the old 8955 converter damage my new batteries, or just not efficiently charge like a new replacement? When not on shore power my 200w solar panel controlled by 30amp PMW in LFP mode provides daily top off. I have a 10amp lithium approved charger I can use on shore power or generator if I need extra charging, I am concerned if the old converter can cause damage to my new battery bank when my travel trailer is plugged into shore power.
Old converter, new LiFepo4 battery bank
- Thread starter wrharmon
- Start date
Daddy Tanuki
Emperor Of Solar
What is it set to charge to?
Daddy Tanuki
Emperor Of Solar
bro we need numbers.... some of them are fine and dandy for lithium remember lithium does not have a memory so as long s it is not overcharging there is no issue... if it charges to 90% every time it will not hurt a thing. give us voltage numbers preferably to the second decimal. IE: 13.45, 13.70 sounds like a huge difference but given enough time either one on them will fully charge. obviously 14 would be better.... the biggest thing to watch out for is temp corrections for FLA batteries. you need to shut that off or set it low enough that you do not overcharge. anything up to 14.4 without temp correction is fine and dandy. also manual equalize only.
I will have to measure the voltage coming from the old converter and get bac to you. The solar controller changed when I changed the settings on it from lead acid to LFP. The old converter (9855) will have to be tested to know exactly what it is sending. I'm thinking I will leave the furnace on all night and draw down the battery, then plug in the trailer on shore current and use volt ohm meter to test voltage coming from converter. I will post again in a day or two. Thanks
Whinny
Solar Enthusiast
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is it a WFCO brand?
www.wfcotech.com
WF-9855 Deck Mount Converter Charger – WFCO Technologies Converters
WF-9855 Deck Mount Converter Charger - 55 amp Power Converter. For a lithium-ready solution, click here. – Converters https://www.wfcotech.com/shop/converters/wf-9855-deck-mount-converter-charger/ WF-9855 Deck Mount Converter Charger
www.wfcotech.com
Daddy Tanuki
Emperor Of Solar
well according to that link it puts out 13.2 for float, 14.4 for bulk and 13.6 for absorb. the real question is what does it do for temp compensation?
14.4 for bulk would put you at 3.6 for bulk tad high but livable for a DIY pack... what do you pre-made batteries recommend?
14.4 for bulk would put you at 3.6 for bulk tad high but livable for a DIY pack... what do you pre-made batteries recommend?
My recollection is just that. The batteries are LiTime 100ah trolling motor with BMS protections for temp and voltage charge and discharge, as well as bluetooth communicating battery status through downloaded app on my phone. I have one battery installed outside on the trailer tongue in a batttery box. I just removed the old batteries and connected this one after it was fully charged and balanced itself.
I guess I was worried since on this forum I had read I was going to have to change controller. I purchased a 10amp lithium battery charger to "wake up" my new batteries before installing them and to use when I have shore power independent of the installed converter.
I operate constantly with the motto, "a little knowledge is a dangerous thing." An I am learning this a little bit at a time, I want to be cautious.
Thank you for your input.
I guess I was worried since on this forum I had read I was going to have to change controller. I purchased a 10amp lithium battery charger to "wake up" my new batteries before installing them and to use when I have shore power independent of the installed converter.
I operate constantly with the motto, "a little knowledge is a dangerous thing." An I am learning this a little bit at a time, I want to be cautious.
Thank you for your input.
Daddy Tanuki
Emperor Of Solar
like I said the big question is what does it do in regards to temp. most chargers setup for lead acid will rmap the voltage up to ensure proper charging in cold weather. this is not desirable with lithiums. your BMS should cut current when it goes over a certain threshold, but you do not really want to rely upon that, if the unit can be adjusted or set for different voltages, i would shut off temp corrections, and leave the rest as it sits.
I have experience with this application. Due to the converter being designed for lead acid, it'll take your new bank up to around 80% SOC and then take it's sweet time getting anywhere near 13.6 volts and it won't fully charge the lifepo4. It'll work fine and you will still get better performance and life span from your lifepo4 than lead. I bought an external 15 amp charger and plug it in when I want to top the batteries off before a trip.
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