Lead Acid batteries V Gel

[irnbru]

I think we will need to be replacing our leisure batteries soon. The ones that are currently in the van are 2 x110 banner. Would I be better going for another 2 lead acid 110s or 2x80 amp hr ES900 marine, we are very rarely on EHU. What would give us the best usage?

 

[BillyKontiki]

No the state of charge algorithm shows in a percentage of power
Remaining ie 50% or 10% some
Bms systems will close down at 10% some 20% but will not show weakness it will just close down

 

[BillyKontiki]

Whilst I get what you are saying in real world terms you will know when the lithium are getting low on capacity.. I think mine would isolate at 10.5 volts or so..would you let them get that low...,?
They do drop off quickly but running them to say 12.5 v would still give you ample capacity and plenty warning they needed charging..
Remember it doesn't matter what the chemistry..the deeper you cycle any battery the shorter it's lifespan..
Here's the discharge curves on mine..when I had some cause to check them out.. each battery individually and then with the pair paralleled.. but the curves all follow a similar rapid drop off as capacity decreases..but there is still a small drop in voltage as they discharge. ..certainly enough to give a warning of reducing capacity..
Thats on a battery loaded with no charging source like solar connected ..
View attachment 494329

The battery BMS show’s the state of charge on the Bluetooth app as a percentage ie
SOC 30%. Or 80% and my particular battery’s Bms dose not shut down until it’s less than 2%.
So you always know what you have in the tank so to speak.

 

[BillyKontiki]

The battery BMS show’s the state of charge on the Bluetooth app as a percentage ie
SOC 30%. Or 80% and my particular battery’s Bms dose not shut down until it’s less than 2%.
So you always know what you have in the tank so to speak.

Sorry I’ve repeated reply

 

[donkey]

That's interesting, thanks Andy.

Geoff

The battery BMS show’s the state of charge on the Bluetooth app as a percentage ie
SOC 30%. Or 80% and my particular battery’s Bms dose not shut down until it’s less than 2%.
So you always know what you have in the tank so to speak.

That answers my concern, thank you

Geoff

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[irnbru]

Yes about right, the difference with Gels is they need a longer absorption phase to fully charge them, at least 4 hours compared to a standard lead acid of 1 hour. Not as bad as it sounds as the absorption phase only charges at about 1 amp so even when you solar output starts dropping off in the late afternoon you still get enough for the absorption phase.

If you go for Gels you won't be disappointed with them also they have a very long life 10 years is quite common.

Your mains charge says it detects battery type automatically your solar regulator you need to set the switch to Gel.

Ok Ive now got the batteries Just so I'm clear in my head, Is it that it will take about an extra 3 hrs driving to recharge one battery or 2 v the time taken to recharge a 110v lead acid? So the absorption rate is a "phase" ?? and it's that phase that takes an extra 3 hrs? Sorry I'm a bit thick with electrics, can never seem to get grips with it.

 

[Lenny HB]

The absorbstion phase only happens when charging from mains or a solar regulator. Engingine battery charging is much cruder ant the voltage stays up at 14.4v letting the battery take what current it wants, not so kind to the batteries.
Time to recharge the batteries when driving is down to how much you have taken out of them. If you have taken 50 ah out of the batteries you will need to put a bit more than 50ah back in to get them fully charged.

 

[irnbru]

Do we have to take THIS cover off to find the switch to move it to Gel THX

 

[funflair]

Instructions, https://www.cbe.it/newsite/wp-content/uploads/pdfs/000153_03_PRS300.pdf

Setting switch is on the back, and position B for gel.

 

[JJ]

Switch on the light switch... does the light come on?

If "yes" then all is well. Have a sit down outside in the sun with a cool drink.

I reckon there is too much "battery stress" amongst Funsters who are mostly on hook up anyway.



JJ