Lithium start battery

[Mrcoolabah1au]

Just wondering if anyone has done this and how to keep them charge if no using the bus regularly

[T1 Terry]

Just wondering if anyone has done this and how to keep them charge if no using the bus regularly

They can't be mounted close to the engine because they can't handle the heat. Unless you have something that is a constant drain on the battery, they will hold their charge for a long time. Biggest problem is stopping the alternator over charging the battery, but if the voltage regulator is set to 13.6v that won't be a problem.

T1 Terry

[native pepper]

I tried one a few year ago in my cruiser and it failed after a couple of years, but it didn't have a bms and I put the failure down to no bms and the huge temp changes under the bonnet. When it was working, it was great, instant start every time until one day, it just wouldn't turn the engine over. Now it powers a remote security camera.

May be wrong, but you can leave your lifepo4 batteries sitting idle for years without them losing power. I have lifepo4 cells which are over 13 years old and never been charged and still sit at 3.2v. Have no idea what others have discovered with their lifepo4 and would be interesting to hear how long they've let their cell packs sit without being charged.

I'd love to use a lifepo4 starter battery, but know they don't like big temp changes and being under the bonnet, means that's what they get. In my bus, that isn't a problem as the starter batteries sit outside the chassis so don't suffer big temp changes. I'm looking at cell prices at the moment going to build a 24v starter pack, just have to find the right charge controller.

[T1 Terry]

24v isn't quite as bad as 12v when it comes to alternator over voltage. Most 24v voltage regulators are set to around 28v, if you use a balancer on the 24v battery to keep the cells at roughly the same voltage this comes out at 3.5v per cell, only 0.5v above the fully charged point so as long as the cells are balanced, the 8 cell battery should last for decades.

T1 Terry

[Mrcoolabah1au]

Ok go back to battery charger

[nut17]

This guy has been running a 300 AH Sinopoly LiFePO4 battery pack in his Mitsubishi Canter based motorhome for the last six years as a combined starting / house battery. This set up has performed faultlessly for the entire time (he is full time on the road) and his annual capacity test allows him to take a full 300 AH out of the battery and only 11.5 volts remaining it still easily fires up his 3.6 lt diesel engine.
https://www.nzmotorhome.co.nz/forum/vie ... ry&start=8

Post by Scubadoo - Neville who is a moderator on nzmotorhome.co.nz

"Quote" I can't remember the last time I observed 50% on our battery monitors. Without checking perhaps 2 or 3 times over 5 years.
100Ah (33%) remaining has never occurred except during the annual capacity test.
FWIW A reading of 0% (11.5V & 300Ah discharged) on our Votronic battery monitor during capacity testing and the battery will still start the truck. Try that with LA.

I don't anticipate ever successfully making a prorated warranty claim. Proving care could be tricky.
2000+ days so far delivering more or less 100Ah when the sun ain't shining and still a 300Ah battery is good enough for me even if it died tomorrow. "End Quote"

Cheers
Chris

[T1 Terry]

Yeah, the house battery in the Mazda is also the start battery. Probably 8 yrs old if not more, but one cell group has failed due to the stupid roof vent fan turning itself on each time the sun powers up the solar panels and the 12v 200 amp Gigavac welding the contacts in the closed position .... thought I'd replaced every one of these with the bigger 350 amp unit but apparently not ....... It was the 4 cells I'd used to replace the cells I cooked way back when I first built the battery pack and I used 4 of the cells I'd used for the torture testing in the very first testing of just what these cells could do ...... I'll have to check the date on the photos to get an idea of just how old those cells were, but they were the only group to go into reverse current because they had been drained below zero volts, probablt because the torture testing reduced their capacity slightly.

Interesting, the toasted cell photos are dated March 2013, so close to the 8 yrs, the cell torture photos date back to July 2011 and the photo of the cells in the box when we first picked them up from the freight mob is dated June 2011 and we bought the cells at good price because they were 3 yr old stock Trev wanted to clear from his stock because he no longer wanted to carry 90Ah Thundersky cells because they were the old LFP chemistry and not the better LYP chemistry of the new (at the time) Winston battery cells.

If these cells hadn't been murdered they might still be working fine, the other 12 cells are still ok so these 4 cells sacrificed themselves and saved the rest of the pack .... it was probably only 1 cell that failed in the 4 cells in parallel, we just weren't paying attention so didn't hear the low cell alarm voltage warning because the Mazda was parked well away from the workshop at the time.

So the the 12 cells that are still working fine are at least 13 yrs since manufacture and 8 yrs in full time service, so much for the experts claim these cells only have a 10 yr life, even if left sitting on the shelf ......

T1 Terry