Has anyone here tried using a Lithium Ion battery, Lithium Irion Phosphate to be specific, as a replacement starter batter for OPE? I have a HF Predator 3500 inverter generator in need of a new starter battery. I exercise it about one hour every three months, but that's not enough to keep the battery charged, at least not in the dead of winter. LiFePo4 batteries have a much longer lifespan, much less charge loss in standby, but are more fussy in terms of charging voltage. Any firsthand experiences would be appreciated. Thanks in advance.
LiFePO4 Batteries for Starting OPE?
- Thread starter Astro_Guy
- Start date
I would expect you need to install a proper charger aswell. Something that creates the proper voltage and current for safe and proper charging from what is available.
I've used a few different brands of LiFePO4 batteries in motorcycles and in one experimental aircraft. They work incredibly well, as long as the temperature is warm enough. On very cold days, they fail to perform until they warm up. Which might happen with multiple starting attempts, or might not.
Charging at low temps can be dangerous.
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You need to figure out what your existing charging circuit is. As eljefino mentioned, it's likely to just use a magneto pulse, rectified through a single diode. You could use a full wave bridge rectifier to gain more output efficiency, even parallel some schottky diodes, but still you aren't likely to gain enough voltage to make up for the voltage drop, if you use a filter cap on it as the supply to a regulating charger circuit that the LiFePO4 needs. You'd typically need about a 2V margin at the target current, while the likely magneto setup isn't designed for this much overhead or else it would overcharge the battery that much more during continuous use.
In other words, I like the idea to continue using a lead acid battery with a trickle charger, or use a ~120VAC float charger with a LiFePO4 instead of expecting the generator to be able to charge it.
I took a look at one of the three, manuals HF has for that Generator and it shows there is a 12VDC, unregulated output for it. That is "probably" separate magneto coils, but it is curious that they state, not to use it while using 120VAC output too. Even so, it is good for up to 8A current, so there is plenty of margin there, to use a switching boost voltage module to get enough voltage margin to power a LiFePO4 charging circuit. This is possible to do, but does not seem as practical (and is more expensive than, and more to troubleshoot now and later) as just using a 120VAC float charger for whichever battery chemistry you decide upon.
In other words, I like the idea to continue using a lead acid battery with a trickle charger, or use a ~120VAC float charger with a LiFePO4 instead of expecting the generator to be able to charge it.
I took a look at one of the three, manuals HF has for that Generator and it shows there is a 12VDC, unregulated output for it. That is "probably" separate magneto coils, but it is curious that they state, not to use it while using 120VAC output too. Even so, it is good for up to 8A current, so there is plenty of margin there, to use a switching boost voltage module to get enough voltage margin to power a LiFePO4 charging circuit. This is possible to do, but does not seem as practical (and is more expensive than, and more to troubleshoot now and later) as just using a 120VAC float charger for whichever battery chemistry you decide upon.
I am leaning that way, but will up the game from simple sealed lead acid to AGM.
LiFoPe4 batteries typically do not like greater than a 1C discharge rate so are not great for starter batteries in most applications.
Here's one rated for 40C continuous draw and 150C burst, most are not using 18650 cells anymore in their battery packs. Their mostly going to the flat packet style cell that allows a much higher current rating and better thermal performance.
I have MANY small engines in my garage that use batteries. The batteries last for years and years and years. I'm actually surprised when I have to change a battery, its so rare. Of course, the batteries are kept in good condition with a battery tender.
I highly recommended that you get a battery tender on your battery. It doesn't need to be a fancy or expensive battery. Just replace it with a stock style lead acid battery, put a pig tail on it, and plug a battery tender to it. The battery will last 7-10 years or longer....
I personally don't leave the battery tenders on all the time. I have had them malfunction and boil the fluid out of a battery. So I use a timer. They are programmed to come on once per week for about 4 hours per week. This is enough time to keep a charge on the battery and in good shape.
Walmart sells the small battery tenders for a little more than $20.
Some of the new Predator generators are now coming with a lithium battery because of this "problem". The lithium doesn't self discharge as quickly as a normal lead acid battery. I'm old school. I think the lead acid batteries are just fine. You just have to take the time to maintain them properly.
I highly recommended that you get a battery tender on your battery. It doesn't need to be a fancy or expensive battery. Just replace it with a stock style lead acid battery, put a pig tail on it, and plug a battery tender to it. The battery will last 7-10 years or longer....
I personally don't leave the battery tenders on all the time. I have had them malfunction and boil the fluid out of a battery. So I use a timer. They are programmed to come on once per week for about 4 hours per week. This is enough time to keep a charge on the battery and in good shape.
Walmart sells the small battery tenders for a little more than $20.
Some of the new Predator generators are now coming with a lithium battery because of this "problem". The lithium doesn't self discharge as quickly as a normal lead acid battery. I'm old school. I think the lead acid batteries are just fine. You just have to take the time to maintain them properly.
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Okay, so returning to this topic...
I have the original battery removed and charging on a 500 MA float charger. Seven hours into this the charger isn't reporting a full charge on the battery. Similar SLA batteries cab be had for $30 while the AGM batteries go for $60. If the original battery doesn't accept a full charge after 24 hours then I will drop $60 for the AGM battery.
I had exercised the generator for over an hour a few weeks ago but this wasn't enough to charge the battery to the point where the starter would even click. Odds are that I will be purchasing a new battery. Kudos to whoever suggested making a pigtail for charging; that's definitely a part of the plan.
I have the original battery removed and charging on a 500 MA float charger. Seven hours into this the charger isn't reporting a full charge on the battery. Similar SLA batteries cab be had for $30 while the AGM batteries go for $60. If the original battery doesn't accept a full charge after 24 hours then I will drop $60 for the AGM battery.
I had exercised the generator for over an hour a few weeks ago but this wasn't enough to charge the battery to the point where the starter would even click. Odds are that I will be purchasing a new battery. Kudos to whoever suggested making a pigtail for charging; that's definitely a part of the plan.
The original [cheap Chinese] SLA battery was left on the charger overnight. By morning the charger had switched from bulk charge to float. Encouraged by this progress, I put the battery back in the Predator along with a 10 AWG pigtail for charging.
On the first attempted start it was obvious that the battery was weak because it turned over very slowly but would not start. I connected up the charger which naturally went right into bulk mode. Thirty minutes later I checked on things and found the charger back in float mode. That was encouraging, so I tried to start it up with the charger attached. This time it turned over slower than the first time and quickly stopped turning at all. Another twenty minutes later I checked on it and found the charger back in float mode, then attempted to start it with no joy. At that point I decided it was time for a new battery.
Another twenty minutes later I went out to remove the battery and head out for a replacement but once again found the charger back in float mode. Once again I tried starting it, and this time it fired up. For now the charger is still on it. While I have my doubts about this battery it may get me through another season.
This being an oil forum, the oil in use is 5w-40 RT6 and the outdoor temperature went down to only 35 F last night. The generator is stored in the garage. Although we had much colder temperatures earlier in the week, it would be safe to assume that the oil was above 32 F for all of these attempted starts.
My charger has only two modes: bulk and float. It doesn't give me any indication of a full charge. Any recommendations on an economical yet more advanced charger?
On the first attempted start it was obvious that the battery was weak because it turned over very slowly but would not start. I connected up the charger which naturally went right into bulk mode. Thirty minutes later I checked on things and found the charger back in float mode. That was encouraging, so I tried to start it up with the charger attached. This time it turned over slower than the first time and quickly stopped turning at all. Another twenty minutes later I checked on it and found the charger back in float mode, then attempted to start it with no joy. At that point I decided it was time for a new battery.
Another twenty minutes later I went out to remove the battery and head out for a replacement but once again found the charger back in float mode. Once again I tried starting it, and this time it fired up. For now the charger is still on it. While I have my doubts about this battery it may get me through another season.
This being an oil forum, the oil in use is 5w-40 RT6 and the outdoor temperature went down to only 35 F last night. The generator is stored in the garage. Although we had much colder temperatures earlier in the week, it would be safe to assume that the oil was above 32 F for all of these attempted starts.
My charger has only two modes: bulk and float. It doesn't give me any indication of a full charge. Any recommendations on an economical yet more advanced charger?
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