Renogy lithium battery dead on the road - help needed!!

Rapt0rUK

Rapt0rUK

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Help needed!

Have a lithium set up that has somehow failed on day 3 of a 1 week trip...

We have the Renogy DC-DC charger and one of their 100ah lithium smart batteries. The Renogy setup appeared to be working fine but this is our first extended road test of the system.

On the drive at home I could see the Renogy box charging the battery from the alternator and the battery indicator light eventually showing the battery fully charged so thought nothing of it and assumed all was good.

We are running LED lights and an Aldi plug in cool box. All has been fine up until just now, 3 days in. We lost power, the battery appears flat and has gone into limp mode, due to battery over discharge.

We've been driving a good couple of hours a each day so had assumed with our relatively low usage we would be keeping on top of the battery charging from the alternator but granted we haven't got any proper monitoring for it yet (waiting for the Renogy monitor to become available in the UK).

I can only assume that it stopped charging at some point along the journey. Must admit haven't been checking the lights on the Renogy box...

Issue we have now, with the engine running the alternator charging light doesn't come on... Only the battery indicator flashing red which means battery over discharged.

Reading the documentation on the Renogy site, it suggests in this situation connecting to an 'external charger with lithium activation feature'. I can find no real information out there on this though and have to assume the Renogy DC-DC doesnt offer this??

Anyone got any ideas on where to go from here..?

Ultimately we can manage without lights etc for the rest of the trip but I'm not even sure to go with it when we eventually get back home...
 
I'd suggest its the cool-box. A peltier will take around 4 or 5 amps, it never cuts out, just a constant drain and 2 hour charge wont be enough to replenish 22 hours of constant 5 amp drain. I dont know the Renogy unit but maybe this is what the leds are indicating?
Cheers
Phil
 
It sounds like you’ve over discharged the battery & it’s locked out & needs resetting. The Aldi coolbox will flatten the battery in 6-8 hours. I’m not familiar with the Renogy, but it sounds like the BMS (internal?) needs resetting. Anything in the manual? Some Lithium specific mains chargers have the ability to reset the BMS, Optimate springs to mind.
 
You could use a jump lead to jump 12v power over to the output side of the dc-dc. So the dc sees a higher voltage and kicks in...

There will be an in rush of currant so expect a crack.

I think those renogy batterys have the blue plug in button to activate them?

What monitoring are you using.

I'll assume the aldi fridgd is a thermoelectric on one and drawing a constant 5a plus current running the bsttery flat?

Be cautious running the dead flat as it will reduce the recharge cycles.
 
Use jump lead to go across the flat Renogy battery.

With the engine running.

Then activate the button

Hopefully the renogy dc-dc and battery will come back to life... then remove temp jump lead

Then get a proper battery monitor.

Then swap out the coolbox for a compressor fridge
 
The coolbox was just a cheap (£35) job from Aldi with no thermostat so think you're right, it must ha e drained it flat...

The issue now is how to go about reactivating the battery... Does anyone know the correct procedure for that?? It's receiving or at least should be receiving 50a from the alternator but the battery has completely shut down...

I've got the RJ45 cable with me and have put it into shelf mode and back out again but no joy... Still won't charge.

Dell, when you say to use a jump lead, how would that be any different to the power coming in from the starter battery anyway?
 
Salty Spuds said:
It sounds like you’ve over discharged the battery & it’s locked out & needs resetting. The Aldi coolbox will flatten the battery in 6-8 hours. I’m not familiar with the Renogy, but it sounds like the BMS (internal?) needs resetting. Anything in the manual? Some Lithium specific mains chargers have the ability to reset the BMS, Optimate springs to mind.
Click to expand...
Yep this sounds about right, there very little info in the Renogy documentation but from what I found on a general search it sounds like you need to put a lower charge through it to reactivate it...

Strange thing is the coolbox has been on 24hrs since we left Manchester 3 days ago... So we must have just been staying on top of it each day with the driving but never getting back up to full and we've eventually cross the line...
 
OK heres what I'd do to rescue the holiday.
Nip into town, find a camping shop & buy a 'tent' EHU hookup set, then to Halfords for a lithium-capable mains charger, then leave it all connected whenever you're on site. Also if you can find a 12v fag-socket mains power supply, that will relieve your battery from coolbox duties.
Its unwanted & unexpected expense, but if you dont rescue your lithium battery it will cost much much more :)
 
Dellmassive said:
Use jump lead to go across the flat Renogy battery.

With the engine running.

Then activate the button

Hopefully the renogy dc-dc and battery will come back to life... then remove temp jump lead

Then get a proper battery monitor.

Then swap out the coolbox for a compressor fridge
Click to expand...

Just so I'm completely clear do you mean bridge the terminals on the leisure battery with a jump lead whilst the engine is running?

Compressor fridge getting ordered as soon as we get home and Renogy tell me they should have the monitors in 'mid-august' so hopefully have that very soon.
 
Phil_G said:
OK heres what I'd do to rescue the holiday.
Nip into town, find a camping shop & buy a 'tent' EHU hookup set, then to Halfords for a lithium-capable charger, then leave it all connected whenever you're on site. Also if you can find a 12v fag-socket mains power supply, that will relieve your battery from coolbox duties.
Its unwanted & unexpected expense, but if you dont rescue your lithium battery it will cost much much more :)
Click to expand...
Good idea... Do you think a charger will reactive the battery though? My only thoughts are if this thing would accept charge, wouldnt it take it from the alternator? I think it needs reactivating somehow...
 
Not sure about resetting - they're all different...
I dont know the Renogy spec, but even if it was 20 amps, thats only 40Ah from a 2-hour drive - 40Ah is only 8 hours with that coolbox, you're drawing a quarter of the charge current so at best it can only last 4x as long as the two-hour charge... if the Renogy is only 10A then only twice as long as the charge time....
 
Salty Spuds said:
It sounds like you’ve over discharged the battery & it’s locked out & needs resetting. The Aldi coolbox will flatten the battery in 6-8 hours. I’m not familiar with the Renogy, but it sounds like the BMS (internal?) needs resetting. Anything in the manual? Some Lithium specific mains chargers have the ability to reset the BMS, Optimate springs to mind.
Click to expand...
Just a caveat about the Optimate Lithium chargers before you rush out & buy one. They will only charge a battery that is NOT connected to a load, if a load is connected during the charging cycle, the charger will go into error & lock out. So in a campervan system, if the fridge kicks in or you put the lights on whilst the optimate is connected, it will think there's a fault & stop charging.
 
Phil_G said:
Not sure about resetting - they're all different...
I dont know the Renogy spec, but even if it was 20 amps, thats only 40Ah from a 2-hour drive - 40Ah is only 8 hours with that coolbox, you're drawing a quarter of the charge current so at best it can only last 4x as long as the two-hour charge... if the Renogy is only 10A then only twice as long as the charge time....
Click to expand...
The charger draws 50amp which is why we went for it, the hope was that at that level with an hour or so driving a day we would have stayed on top of it but it seems the plug in coolbox just isn't efficient enough... Compressor fridge needed.

There's a Halfords 45 mins away so will head there and see where I get to...


Huge thanks for the advice guys!!
 
Salty Spuds said:
Just a caveat about the Optimate Lithium chargers before you rush out & buy one. They will only charge a battery that is NOT connected to a load, if a load is connected during the charging cycle, the charger will go into error & lock out. So in a campervan system, if the fridge kick in or you put the lights on whilst the optimate is connected, it will think there's a fault & stop charging.
Click to expand...
I've pulled all the fuses from the fuse box so there's no draws from the battery at all as it stands. Will see if halfords have something that can help...
 
Rapt0rUK said:
I've pulled all the fuses from the fuse box so there's no draws from the battery at all as it stands. Will see if halfords have something that can help...
Click to expand...
yeah, but going forward, the Optimate would be useless to you in the future as a EHU charger for your battery.
 
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