Fuso wont start...

[dwh]

Good god...

This as bad as the guy at the auto parts store that says gels are better than lead-acid. (Gels ARE lead-acid.)



Flooded lead-acid: lead plates with diluted sulfuric acid electrolyte. Removable caps to check and add water.

Maintenance free (sealed) lead-acid: same thing but with non-removable caps and a pressure relief valve. Caps have a catalyst to recombine hydrogen and oxygen.

Absorbed Glass Mat (AGM) lead-acid: same as sealed but with fiberglass fabric sandwiched between the plates to act as a sponge for the electrolyte.

Gelled lead-acid: again same thing (sealed), but with a gelling agent added to the electrolyte to hold it in place instead of fiberglass.



Cranking battery: many thin lead plates to conduct high peak currents over short bursts.

Deep cycle: less but thicker plates to last longer (plate decay takes more years) under constant loads.

Marine: usually medium plate thickness that does a medium job of cranking and lasts a medium amount of years deep cycling.


You can buy flooded cranking batteries or flooded deep cycle batteries.

You can buy flooded maintenence free (sealed) cranking batteries or flooded maintenance free deep cycle batteries.

You can buy absorbed glass mat cranking batteries or absorbed glass mat deep cycle batteries.

You can buy gelled electrolyte cranking batteries or gelled electrolyte deep cycle batteres.


The frickken fiberglass between the plates doesn't make AGM any different than any other lead-acid battery. It's just a sponge.

AGMs and Gels were originally made as cranking batteries for airplanes. (Charlie don't slosh!)



There are a couple of oddballs. One is Odyssey TPPL where they use lots of thin pure lead plates and lots of thin fiberglass smooshed into a sandwich under high pressure to create a battery rated for both cranking or deep cycle.

Another is Optima Spiral Wound where they take the plates and fiberglass fabric and roll each 2 volt cell into a Little Debbie Swiss Roll. (You can buy them in ether cranking or deep cycle.)

But really, those are both just absorbed glass mat sealed lead-acid batteries.

 

[dwh]

And deep cycle batteries can do cranking, but having less (but thicker) plates, they don't produce as many peak amps.

Cranking batteries used for deep cycling don't last long because the thin plates either decay faster or they overheat, warp, and short out.

 

[dwh]

And the pressure relief valve on a sealed battery is there because whenever a lead-acid battery is being charged, electrons occasionally bounce off water molecules just right to cause the molecular bond to let go, separating water into hydrogen and oxygen.

You don't want that to escape since you can't replace the lost water, so you seal the battery and use a platinum catalyst to recombine the hydrogen and oxygen into water.

But if the battery overheats, you don't want it to split open. So you add a pressure relief valve and just live with the fact that any hydrogen and oxygen it lets out your battery will never get back.

 

[gait]

which explains why AGM have higher at rest volts than Wet Cells, better charge acceptance, lower internal resistance, and lower Peukert Exponent?

 

[dwh]

which explains why AGM have higher at rest volts than Wet Cells, better charge acceptance, lower internal resistance, and lower Peukert Exponent?

Yup.

Maximizing the contact area between the electrolyte and the plates by using a filler to spread the electrolyte does have benefits other than just to prevent sloshing.



The point is - comparing "AGM vs. cranking batteries" is completely wrong. AGM is a way of building a lead-acid battery which can be, and is, used to make either cranking or deep cycle batteries.

It's like comparing "radial tires vs. heavy duty tires" - it makes no sense when there are plenty of heavy duty radials.

 

[C p weinberger]

Tutorial appreciated ?

 

[dwh]

No worries.

 

[flossandfredsadventures]

Yup.

Maximizing the contact area between the electrolyte and the plates by using a filler to spread the electrolyte does have benefits other than just to prevent sloshing.



The point is - comparing "AGM vs. cranking batteries" is completely wrong. AGM is a way of building a lead-acid battery which can be, and is, used to make either cranking or deep cycle batteries.

It's like comparing "radial tires vs. heavy duty tires" - it makes no sense when there are plenty of heavy duty radials.

To further this (although perhaps a bit of a sidetrack for the thread), would you say a decent pack of LiFePO4 cells could be happily used for cranking if it was stored in the camper body where the temperature and overall environment was kept to its liking?

 

[dwh]

To further this (although perhaps a bit of a sidetrack for the thread), would you say a decent pack of LiFePO4 cells could be happily used for cranking if it was stored in the camper body where the temperature and overall environment was kept to its liking?

Absolutely. Depending on how the cells and battery mangement system are configured.

There are drop in LiFePO replacements for 12v vehicle batteries. The main problem is max amperage draw (leaving aside temperature problems). BattleBorn for instance are rated to a max continuous flow of C*1 (in or out) so a 100ah BattleBorn can be charged or discharged at 100a continuously.

But their onboard BMS will allow up to 200a for up to 30 seconds. A pair in parallel would allow up to 400a for 30sec which would be more than enough for most starters.

 

[dwh]

Or, combine a LiFePO with a capacitor bank to handle starting.

https://m.youtube.com/results?search_query=capacitor+car+battery

 

[flossandfredsadventures]

So to bring this back to Canters - I believe the starter motor is rated at 3kW on the 4M50 4.9L, (250A @12V) so to keep to around the 1C that LiFePO4 is happy to discharge at, 4x60Ah prismatic cells should suffice for cranking duties?

That use of capacitors for starting is a rather interesting concept - I'm impressed!

 

[dwh]

Dunno about cells. Haven't studied the specs because I have no interest in rolling my own. If at some point in the future I switch over from my 400ah AGM house bank to LiFePO I'll buy off the shelf 12v drop-in kit from a reputable manufacturer so I can reuse the rest of the electro-stuff I've already got.

 

[Buckstopper]

Simon - Did you get rolling? When you visited my house to look at my Fuso you saw my Porshe 914 EV with its 94 100 Ahr LiPO cells and BMS issues. I have a bit of experience on this subject. Look at http://www.evalbum.com/4059

I have considered combining both starting loads and house power to a single chassis mounted pack. You could easily fit two packs of 4 of the 100 Ahr 3.2V cells from my car for 200 Ahr at 12 volt nominal in the stock battery holder on the Fuso. The challenge is a BMS that would keep the cells charged from the truck alternator. Combine that with power from solar panels on the camper roof which has a totally different charge curve. If someone can crack that nut it would definitely save weight and use less space but I wouldn't want to be in the middle of nowhere and find out it wasn't working. The other concern I have is that the pack would be rather exposed hanging on the side of the truck.

I have enough cells sitting in my shop to do it but just don't want to go there.

********

 

[gait]

Simon - Did you get rolling? When you visited my house to look at my Fuso you saw my Porshe 914 EV with its 94 100 Ahr LiPO cells and BMS issues. I have a bit of experience on this subject. Look at http://www.evalbum.com/4059

I have considered combining both starting loads and house power to a single chassis mounted pack. You could easily fit two packs of 4 of the 100 Ahr 3.2V cells from my car for 200 Ahr at 12 volt nominal in the stock battery holder on the Fuso. The challenge is a BMS that would keep the cells charged from the truck alternator. Combine that with power from solar panels on the camper roof which has a totally different charge curve. If someone can crack that nut it would definitely save weight and use less space but I wouldn't want to be in the middle of nowhere and find out it wasn't working. The other concern I have is that the pack would be rather exposed hanging on the side of the truck.

I have enough cells sitting in my shop to do it but just don't want to go there.

********

silly question ..... why does the vehicle need an alternator if there's solar? Can it be considered as just a backup?

 

[dwh]

Because even a large vehicle roof covered in solar would have a tough time producing the 100a or more that can be had from an alternator. Plus it's a vehicle, so if the engine is going to be running anyway...