You could have used your leisure battery bank to start your van if you had jumper leads. I can't do that now with my single 105amp lithium battery.
The reason I went with LifePO4 from Fogstar was that they incorporate heating elements in the batteries. If the temps are below freezing, then the BMS activates the heating coils when the charger is connected. Once the battery warms up enough, then charging begins. The heating coils take 10 amps. Temps below freezing won't matter to the output of the battery.
I love the fact that the battery maintains 13.1v even under the load demand by the diesel heater.
I can't believe that some suppliers are charging another £200 for a battery with heating elements.
I very much doubt we will need the heating element facility, as we won't let our van freeze. The battery in mounted high up on the side of my tank and near the diesel heater, so warmth from that will keep the battery warmer when the frostat kicks in.
What's the news on your LiFePo experience, Spruce?
One of our guys moved over to lithium when he was kitting out his new van a couple of months ago and loves it. It's a Sterling set up with a Victron 30A B2B charger and he says he never has to give the battery a thought after years of plugging in a charger every night. Voltage never drops. Just wondering if you're having similar results.
Vin
I need a little more experience with this battery before I can make an assessment, tbh. I purchased it on A900's advice at the beginning of this thread.
What the seller's marketing says, and the reality, seem to be 2 different things. I contacted Fogstar who supplied the battery as I needed clarification on a couple of things.
Fogstar's literature mentions that the 105amp Lifepo4 can be recharged at 100 amps and also be discharged at 100 amps maximum. While that might be true, they don't recommend using the battery like this due to heat causing internal damage. They are also advertising it as a drop in battery. (Take your leisure battery out and replace it with Lithium. I question that.) I believe we need a B2B charger with a lithium charging profile. Especially is this true if our van has regenerative braking. A 30 amp Victron b2b charger is ideal as we can easily change the charging profile via the Victron app. I can't do that with my Sterling unit. (Set at 30amps the max my battery charges at is 25amps. The 20 amp 230v charger does 16amps.)
They recommend charging at 50amp max to preserve the battery's longevity. That's apparently fine for charging a 105 amp lithium battery, but Fogstar recommend charging at 20 to 30 amps, as it is kinder to the battery. I have a 60amp Sterling BB1260 which I have reset to 30 amps.
What Fogstar recommend is to fully charge the battery to 100% and then switch the charger off. (I purchased a 20 amp 230v charger from Fogstar.) They don't want the BMS kicking the charge to the battery on and off when fully charged. (You must not put a Lifepo4 battery into a float charging profile like you can with lead acid batteries.) Then they suggested I let the charge drop to 40% capacity and then recharge again.
That sounds good, but something happened 10 days ago at 50% battery capacity. The BMS (have an app on my phone) showed 54% when we got to our first clean 8 miles away. I started the diesel heater when we arrived. The heater had just started to get going past the initial heavy current draw start up phase when it cut out. The low voltage code was flashing on the heater's troubleshooting LED.
I looked on the app, and the battery was showing 14%. We weren't at the first clean for more than 5 minutes. In a few moments after I ran the engine, the BMS showed 50% charged. I switched the engine off, and we carried on throughout the day with 4 big jobs within 1/4 of a mile radius of each other, with the heater going all the time. I think there could have been a glitch in the BMS.
I'm letting the capacity drop slowly again to further test for a repeat.
In the evening of this day, I fully recharged the LifePO4 battery for the first time since fully charging it in the middle of December 2023, when I purchased the battery. So I definitely don't need to bother with it like I did when I had lead acid leisure batteries. This is, providing I've been given the right information.
These Lithium LifeP04 batteries do have similar characteristics that Lithium-ion batteries do. My battery charges at 25 amps with my Sterling b2b charger when the battery is below 80% charged, but it drops to 16 amps at 80% and down to 8 amps above 90%. According to the manual, the charging profile Sterling have programmed Lithium for is a charge voltage of 14.4v with my B2B charger. It's actually 13.6v; so software programs are modified regularly and the manuals not updated.
If I wasn't using the diesel heater (which I've been doing this winter) then my feeling is that the alternator will be able to replenish the current drawn during the day with just the 2 pumps running. We do very little daily mileage.
The battery weighs about 10kgs, so is much lighter than the equivalent lead acid leisure battery at around 24kgs. It's also much smaller. The terminals are 8mm bolts, so ring terminals are needed to supply current to the equipment on board. It's not really a battery that can be charged outside the van, and definitely not overnight in the house. In fact, the instructions warn against charging in the house.
UPS delivered it, and as lithium batteries are classed as dangerous goods, there is a lot of paperwork that came with it; something that didn't go down too well with me. I was nervous about buying the battery to begin with. Instructions on the package tell us to open the packing outside; although the same instruction came with the replacement starter battery for my wife's car we received a couple of weeks earlier. The LifePO4 are considered safer than the Lithium-ion batteries used in scooters and EV's. But they aren't as dense and haven't got the 'punch' lithium-ion batteries have.
Fogstar batteries come with an internal heating element inside the battery. If the battery is freezing, then the charging power is directed into the heating element and once the battery is warm, charging automatically begins. The heating element on the 105amp battery draws 10 amps.
Sorry, some of these points I've mentioned in other posts, so I'm repeating myself.
In the future, I might reinstate the 60 amp charging facility the Sterling unit has, to see the result. I expect the charge amperage will be about 5 amps higher than the recommended 50 amps. It's probably best done in winter when the battery is generally much colder. The BMS app also has a temperature readout.
