Lithium & other advice/facts

[oldtrack123]

Peter, how often would you repaste then?

Hi Dapope
As I said that was with a Utilux product & was over 25 years ago that they were redone
I retired shortly after we redid them ,So do not know how they went the 2nd time
My message is simply do not wait for 20years check regularly

Fairly easy to do with a sensitve multi meter[one that will read micro volts]
Take readings NOW with cell under a known load that you can repeat
Measure between the actual cells' terminal and the connections as close as possible to the cell terminal & between connection & conection
They should ALL be VERY close to the same reading

That will give you an indication of a clean new setup
Record readings [even on the connectors] then say do 1st check after 6months
if no significany change repeat yearly !!

PeterQ

[T1 Terry]

The cell logger reads to 3 decimal places, if a cell reads high when charging but low under load compared to the others, a bad contact should be the first thing checked.
General service and check bolt tensions and top up charge cell balance 12 mthly is about all that's needed.

[bellett65]

The system is/was running great then wham. Blown fuse. Not really happy as it was the fuse between the charger, and SSR. The bit that is confusing is that the charger was not on in any shape or form.So far I am putting it down to loose connection and possibly low soc. But why does it happen after dark and not in daylight hours. Maybe shades of Murphy coming in to play.

Peter

[erichaussie]

Blown fuse. Not really happy as it was the fuse between the charger and SSR.
Peter

No chance of that happening in my setup - no fuse between charger and SSR! The cable between the two is very substantial - way above the capacity of the charger - and does not need protection. If anything goes wrong the fuse in the charger should take care of that.

[T1 Terry]

My charger set up using the alternator via a solinoid to the lithium house batteries is a dismal failure. It won't charge the house battery above around 30% SOC, seems the alternator charge voltage isn't high enough to pump much charge in unless it's very flat, like 0% SOC
Wish I'd left the other 500w inverter in the bus now, I could have at least mounted a 20 amp charger and got something into the house battery.
When the battery voltage is very low the current is so high it melted the AG5 fuse holder, another problem to sort
Can't complain really though, what other battery would have put up with this sort of abuse and still function?

[jon_d]

My charger set up using the alternator via a solinoid to the lithium house batteries is a dismal failure. It won't charge the house battery above around 30% SOC, seems the alternator charge voltage isn't high enough to pump much charge in unless it's very flat, like 0% SOC

Terry, how low is the voltage?

Drop a diode into the sense line of the alternator and have a NC relay shorting it out. Have the coil of the NC relay powered by the solenoid signal.

When the solenoid is turned on, the relay opens and the sense voltage increases by 0.6V (forward voltage drop)


The reason for using a NC relay is that it's a fail safe. Something is always in circuit and the alternator will not run away during the break before make action.

jd.

[T1 Terry]

Hi Jon, great to see you here. The alternator saga is a long one. It appears there is a mismatch between the alternator pulley size and the water pump and crankshaft pulley size, the alternator is an 11Asection and the other 2 are 13A section. The belt slips under high load/speed and has overheated the alternator and the high load place on it when the house atterirs are very low has finaly finished it off I think.
If I can rewire the 2500w inverter to the start battery and connect a 20 amp charger it will at least minimise the load, hopefully that will be enough to get us through the rest of the trip and back home again.
It seems the high charge acceptance rate of the lithium batteries all the way to fully charged combined with a large battey pack (360Ah) is all to much for a standard automotive alternator, they just get too hot under the constant high output, add the slipping belt problem and it's all too much for it.
When we get home I'll either look at fitting a high capacity alternator with the tripple fans like the cruising boats use, or set up an inverter/charger system to limit the load.

[bellett65]

Blown fuse. Not really happy as it was the fuse between the charger and SSR.
Peter

No chance of that happening in my setup - no fuse between charger and SSR! The cable between the two is very substantial - way above the capacity of the charger - and does not need protection. If anything goes wrong the fuse in the charger should take care of that.

The ironic thing is that the charger was not switched on. I was running on a wing and a prayer with 25% soc. The fuse holder melted and the cobble up to get through the night was a mixture of cable ties and luck. I have replaced the fuse holder and when I get home some large cable will be in order.

Peter

[dapope]

get some 90mm stuff, you will never run out of juice!!
My battery balancer/meter arrived. I hooked it up on the 90AH battery. Told me that there was 91% capacity remaining, no need to balance cell(3.45 to 3.47 I pushed the balance button anyway. How awesome is that???!!!!
It does prefer a positive feed for power, and a separate 12v feed in to work, but other than that its all good!
When I get the shwagman back, I will mount it in permenantly

[Craig]

I would have thought a breaker like the "short stop breakers" would be a better option for a constant high current set up.