Charging ebike batteries when not on hook up (1 Viewer)

[Lenny HB]

Lenny HB
Would a 500 watt PSW inverter be up to charging one ?

Should be more than enough, I fitted a 1000 watt so if necessary I could charge both bike batteries but I don't do that very often as it really hammers the batteries.

 

[mushy]

How often do people charge their batteries. I was told when I bought mine to let them run down as far as safely possible before charging but I have heard other people say they keep them topped up all the time.

 

[Mikey RV]

I just let mine run down, but if it’s say half charged and I am going on a big ride I will charge it up to 100%.

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[George Thomas]

Hi Paulj - this probably won't be of any help but we charge our two ebikes from our 2000 watt inverter powered by two 100 amph lithium battery setup with solar etc. Just like being on hookup. Have a word with VanBitz they can give some advice when they return to work. All the best George

 

[Wh05apk]

We've just charged 2 500wh batteries today , we have 420w of solar, 246ah gel batteries and 2000w inverter, solar was giving about 18a and met draw was about 8-9a to charge 2. Worked perfectly, a bit of exercise for the batteries which have done nothing for months......

 

[jezport]

I have a 140w solar panel and a 1000w pure sinewave inverter. Just charged my 2 bike batteries while on the drive today.

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[Compactliner]

You have to 'pay' for what you use. In other words, put back the energy that you take out.
I think that many may not use their e-bikes much, so won't need to replenish as much as others,
but e-bikes can consume a lot of energy and that has to come from somewhere...
[/QUOTE
i agree, please check my figures/maths....
even a half charge of, say, 5ah requires 20 times that (100ah) when 'inverting' from 12v to 240v (a factor of 20).
the trick is to get that back into the batteries asap....
100w solar roughly produces a max of 6 amp....
200w is 12 amp...
300w is 18 amp...
so, for a middling 200w system producing 12amp per (sunny) hour, this will take 8 hours to replenish a half battery charge...
if you have two ebikes (like we do, and use them almost every day) and you need to replenish them asap, thats one day each with 200 watts of solar, just for a half charge?

 

[Compactliner]

I have a 140w solar panel and a 1000w pure sinewave inverter. Just charged my 2 bike batteries while on the drive today.

hi Jezport, what are the sizes of the batteries and what level were they still charged before putting them on the inverter?
i agree that 2 half charged batteries (say 10 ah total requirement) could be charged by an inverter in say 2 hours, with both plugged in together.....or 4 hours, one after the other.
if my numbers above are right, this would take 200ah from a 12v battery bank..thats an enormous pull...
however, solar could be refreshing this as you go, but a 140w panel produces about 8amp so even 10 hours would only see 80ah being returned.
after charging your batteries, what was the condition of your leisure batteries?
hence my request for someone who knows more about 'leccy' than i do to check my figures.
thanks.

 

[Lenny HB]

If I charge both our 400 watt bosch batteries from flat it takes 60 amps for 2½ hours, that's a 150 a/h out of the batteries. With any luck on a bright sunny day in summer I'll get over half that back from 300 Watts of solar. We have 234 a/h of Gel batteries.
Unless desperate I would only charge both from flat in summer with full sun.

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[Compactliner]

thanks Lenny. those 400wh batteries (same as ours) are about 11ah at 36v, so 22ah to find.
i thnk i can see where you're coming from with your '60 amps for 2.5hrs' as the charger (x2) is rated at 1.5amp input.....so 3 amp total x 20 for ramping up to 240v from 12v..and around 2.5hrs for a full charge.
so charging one battery from half full would require 1.5 x 20 x 1.25hrs....37.5ah.
i have 190ah somthatbshould be ok.
however, i only have 100w solar (at the moment) so this would only generate 6a per hour max and would take 6-8hrs to replenish.
i can see that doubling the solar would help a lot...
as it happens, the two chargers i have are slightly different...mine outputs 4a while OH has a 2a one.....i think im right in saying both have the same input level?
in this case, should i use the 4a to reduce time?....if input requirement the same?
thanks again.

 

[Pausim]

How often do people charge their batteries. I was told when I bought mine to let them run down as far as safely possible before charging but I have heard other people say they keep them topped up all the time.

If they are lithium there is no memory effect so no need to run them down regularly. We just charge them up fully when convenient. Some lithium types are said to be best stored long term at less than 100% full but they are very forgiving compared to earlier types of rechargeable batteries.

 

[jezport]

hi Jezport, what are the sizes of the batteries and what level were they still charged before putting them on the inverter?
i agree that 2 half charged batteries (say 10 ah total requirement) could be charged by an inverter in say 2 hours, with both plugged in together.....or 4 hours, one after the other.
if my numbers above are right, this would take 200ah from a 12v battery bank..thats an enormous pull...
however, solar could be refreshing this as you go, but a 140w panel produces about 8amp so even 10 hours would only see 80ah being returned.
after charging your batteries, what was the condition of your leisure batteries?
hence my request for someone who knows more about 'leccy' than i do to check my figures.
thanks.

Mine are 11.6ah and are probably half discharged, I charge one after another during bright weather and my batteries do not get discharged as solar keeps up. I have 140w solar and 2 AGM batteries at around 87ah each and my solar regulator is a votronic MPPT dual battery with the temperature probe. I see around 8.2A from the solar during charging.

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[Compactliner]

Jesport, thanks for the update.....ive just done my own test so heres what ive found..
as Lenny points out, with a 4a output, the Bosh charger can refill a full battery (11ah) in 2.5hrs...
my 30ml trip yesterday would taken about 40% of my battery, so needs about 60mins of charging ....about 4 ish amps...
i flicked on the inverter and off we went and in about one hour on the dot, the battery was fully charged.
i checked the van batteries every 15mins and everything was fine....
that hour 'should' have taken 1.5a (charger input) x 20 (upscaling factor) x 1 (one hour duration) ....so, 30ah...
however, within a couple of mins of turning off the inverter, the leisure batteries (2x95ah AGM) were showing full...i will check again later..
this is interesting as my solar system only has the capacity to replace 6amps in that hour, so i 'should' have a deficit of 24ah?...
either way, all looks fine but still struggling to get to grips with the maths..
from that test it looks like, on a decent sunny day, i could do one battery (or even two) half charges before going out for the next ride....
thanks for all the help, folks

 

[Lenny HB]

Jesport, thanks for the update.....ive just done my own test so heres what ive found..
as Lenny points out, with a 4a output, the Bosh charger can refill a full battery (11ah) in 2.5hrs...
my 30ml trip yesterday would taken about 40% of my battery, so needs about 60mins of charging ....about 4 ish amps...
i flicked on the inverter and off we went and in about one hour on the dot, the battery was fully charged.
i checked the van batteries every 15mins and everything was fine....
that hour 'should' have taken 1.5a (charger input) x 20 (upscaling factor) x 1 (one hour duration) ....so, 30ah...
however, within a couple of mins of turning off the inverter, the leisure batteries (2x95ah AGM) were showing full...i will check again later..
this is interesting as my solar system only has the capacity to replace 6amps in that hour, so i 'should' have a deficit of 24ah?...
either way, all looks fine but still struggling to get to grips with the maths..
from that test it looks like, on a decent sunny day, i could do one battery (or even two) half charges before going out for the next ride....
thanks for all the help, folks

190 a/h of batteries if they are 95a/h AGM they will soon die if you keep running an inverter.

 

[Compactliner]

theyve done pretty well so far....5 1/2 years.
we did 8 weeks on site this Jan/Feb and, although we had EHU, it was metred so i left the charger turned off....the solar and batteries kept us in power for water pump, heating fan (rarely), charging ipads/phones etc for the whole period.
ive read many a post re: AGM batteries, but ours seem to keep on going...

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[Lenny HB]

theyve done pretty well so far....5 1/2 years.
we did 8 weeks on site this Jan/Feb and, although we had EHU, it was metred so i left the charger turned off....the solar and batteries kept us in power for water pump, heating fan (rarely), charging ipads/phones etc for the whole period.
ive read many a post re: AGM batteries, but ours seem to keep on going...

One of the few lucky ones.

 

[Compactliner]

lovingly cared for, lol....like me.

 

[jezport]

190 a/h of batteries if they are 95a/h AGM they will soon die if you keep running an inverter.

Not if you are getting over 8A of solar charge, the voltage of my batteries stays at 13.2v during charging the bike on a sunny day. On a bright day the voltage still keeps at 12.7v during charge

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[Rodneyplonker]

One of the few lucky ones.

Hi Lenny, We are awaiting delivery of a new Motorhome and it has a 95ah AGM Leisure battery installed. I was thinking of adding another but, from what I have read about them...incl your comment, am slightly cautious. I have also read that, previous problems with AGM batteries were due to them not receiving the full charge necessary (14.7)? Do modern alternators correct this now?
I would prefer to install say 100ah - 150ah Lithium but, not sure about cost and possible other equipment needed if I went that route. The easiest route seems to be to just go with another AGM one? Any advice welcome.

 

[Compactliner]

I guess you could ask the dealer to swap out the single AGM for a Gel 80AH and pay for a second one to be installed.....or even try and blag two.

 

[Rodneyplonker]

The dealer gave me an allowance of £200 towards a second battery because, at the time, they were in full lockdown and as it was uncertain when my vehicle would be registered and that, they had no tech guys at the dealership, it was an easier solution and gave me more scope to do as I wish.
It still doesn’t answer my query of whether or not, past criticism of AGM is still relevant with modern smart alternators... which I believe, is what my van has included because it has the new 9 speed auto box.

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[Rodneyplonker]

To further clarify... if 9 speed auto gearbox is specified, a smart alternator is an automatic upgrade. Don’t ask me why!

 

[Lenny HB]

Hi Lenny, We are awaiting delivery of a new Motorhome and it has a 95ah AGM Leisure battery installed. I was thinking of adding another but, from what I have read about them...incl your comment, am slightly cautious. I have also read that, previous problems with AGM batteries were due to them not receiving the full charge necessary (14.7)? Do modern alternators correct this now?
I would prefer to install say 100ah - 150ah Lithium but, not sure about cost and possible other equipment needed if I went that route. The easiest route seems to be to just go with another AGM one? Any advice welcome.

As I have had bad experience with AGM's on the current van I got rid of the AGM and fitted 3 Gels. Although some people have had AGM's last a few years it appears to be very hit & miss. If like me you rely on your batteries it's not worth the risk .
The main problem with the charging was on the leisure side with the manufacturers using the Gel setting for AGM, that has now been corrected.
If I was buying a new van now I think I would go with Lithhium.

 

[Rodneyplonker]

Thanks, Lenny! Yeah...leaning towards Lithium to be honest! However, we are not going to venture very far in the foreseeable future - and certainly not long term off grid yet so, may just see how the single AGM performs and decide then. Our last two Hymers‘ both had 2x100 solar and 2x90a Varta silver batteries (non AGM) which did everything we needed when in Southern Europe for the winter months...75% wilding or free camping!
Weight-wise, Lithium makes utter sense but, not being very techie myself, I wonder if I would also require other parts of the electrics to be changed or added to, to avoid conflicts or mismatches of any kind? It could then become even more expensive?

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[jezport]

Thanks, Lenny! Yeah...leaning towards Lithium to be honest! However, we are not going to venture very far in the foreseeable future - and certainly not long term off grid yet so, may just see how the single AGM performs and decide then. Our last two Hymers‘ both had 2x100 solar and 2x90a Varta silver batteries (non AGM) which did everything we needed when in Southern Europe for the winter months...75% wilding or free camping!
Weight-wise, Lithium makes utter sense but, not being very techie myself, I wonder if I would also require other parts of the electrics to be changed or added to, to avoid conflicts or mismatches of any kind? It could then become even more expensive?

We have been running the 2 AGMs since Aug 16 and have had no problems up to now. Our solar regulator is set up for AGM so keeps them charged correctly, we also have the tempreature probe connected. The schaudt charger is also set to AGM. Older vans sometimes dont have the correct charger for the AGMs so this may be why people report failures.

 

[Rodneyplonker]

Thanks Jezport. We have the Schaudt Elektroblock EBL119 with Schaudt Solar reg LR1218 and I am assuming that the regulator will be set to AGM? Will check when we collect the vehicle. We are also assuming that setup will avoid early death of the batteries?
As mentioned above... we may just use the single one for a while because we don’t anticipate being away for long periods before the end of the year and will decide then.
it would be nice though, if we could stretch to Lithium - both to save weight and to forget about the issues??