# help with batteries



## bluie (Dec 6, 2011)

:roll: hi all, i wonder if someone can help me, i have 4-6volt batteries at 800amp each coupled together to make 24volt as my truck/motorhome is 24volt, now these batteries are charged from solar panel on the roof and it has a inverter, but lately i have noticed the batteries are very low, they are the leisure batteries, HOW would i go about charging them up, thanks for any help. bluie :roll: :arrow: :roll:


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## BillCreer (Jan 23, 2010)

Hi,

Welcome to the forum. Doesn't your alternator normally charge them?


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## bluie (Dec 6, 2011)

hi bill, no, i'm talking about the leisure batteries not the main batteries and the altenator does not work anyway when the truck/motorhome is parked in the yard. bluie


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## Spacerunner (Mar 18, 2006)

Put them in pairs, connect the two sets in series to total 12 volts each and charge with a normal 12 volt battery charger.

I'm no expert. *please* If I have got series mixed up with parallel could a more knowledgeable member correct the above.


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## BillCreer (Jan 23, 2010)

Hi,

I take it that we are not talking about a conventional motorhome setup then?
On a conventional motorhome all the batteries would be charged when the engine is running and when you plug in to a EHU all batteries would usually be charged.


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## bluie (Dec 6, 2011)

hi bill, no i don't think my truck is very conventional, its a daf lf 45/150 71/2 ton conversion running on 24volt with invertor to 12volt charged by solar, but maybe the panel is not big enough to charge 4 batteries at 800amp output each, i will need to charge them but i'm not shure how to go about it. [dum blonde] lol bluie


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## bluie (Dec 6, 2011)

hi spacerunner,thanks for the info but i would like to be really sure before i get stuck in. regards bluie


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## Spacerunner (Mar 18, 2006)

bluie said:


> hi spacerunner,thanks for the info but i would like to be really sure before i get stuck in. regards bluie


 

I found this....

If you have two 6 volt batteries you can take a jumper wire and connect the negative post on one battery to the positive post on the other battery then connect the remaining pos and neg posts to the 12 volt battery charger.

Read more: http://wiki.answers.com/Q/How_do_you_charge_6_volt_batteries_with_a_12_volt_charger#ixzz1jvw1ApuQ


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## bluie (Dec 6, 2011)

thanks spacerunner, thats really helpful. regards bluie


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## BillCreer (Jan 23, 2010)

Hi,

I think you need to get someone who understands batteries to have a look at what you've got before you attempt anything.

It won't be hard to work out what you need but without a close inspection it is impossible to give you safe instructions on what you need to do.


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## bluie (Dec 6, 2011)

thanks bill,i will take your advice. regards bluie


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## rayc (Jun 3, 2008)

Why not just get a 24v battery charger? It will need to be a bit hefty to recharge from flat in a reasonable time.

battery charge


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## bluie (Dec 6, 2011)

thanks rayc, yes i might go in that direction,i just was not sure where to connect up with a inverter in the mix. regards bluie


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## rayc (Jun 3, 2008)

bluie said:


> thanks rayc, yes i might go in that direction,i just was not sure where to connect up with a inverter in the mix. regards bluie


The 24v charger should connect to the output terminals of the battery bank i.e. the ones which go to the load [equipment].
I assume you have a 12v inverter which is connected across two adjacent in series 6v batteries? The battery charger should not affect it as it would still only get 12v at its terminals.


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## bluie (Dec 6, 2011)

thanks rayc, much obliged. regards bluie


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## Pudsey_Bear (Sep 25, 2008)

bluie said:


> thanks rayc, much obliged. regards bluie


The 12/24 volt mix is sometimes complicated and only someone who has this set up or someone who is well versed in vehicle electrics will be able to help you.

I'd be inclined to whip it into a pukka auto electricians and it'd be money well spent, you'd not melt anything, and it might work out cheaper.

As a non sparky, I think I would make the leisure side all 12v (assuming you don't need 24v in the hab area) and if poss fit a 12v alternator as well as the 24v one.

The solar panel should charge it well enough if it's kept clean, 4 x 6v batteries is the best way to work they just need reconfiguring to make it 12 not 24 volts, apparently they last longer and work better than 12v ones.

Are you going to post some pictures of your conversion in the self build section as I for one would love to see them.

Good luck with sorting it all out, it shouldn't be to expensive.


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## Vennwood (Feb 4, 2007)

I agree with Kev_n_Lis

If the engine alternator doesn't charge the leisure batteries and the only thing that does is the solar panel(s) what else in the camper needs 24v ? unless you have all 24 volt bulbs. 

IF everything is 12 volts then much less complicated to configure to 12 volts. The solar regulator needs disconnecting first and then connect the batteries to the regulator BEFORE reconnecting to the solar panel. That way the regulator will automatically configure to 12 volt charging.

Remember though that at this time of year solar panel output is pretty poor so don't expect solar to whack in loads of amps


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## bluie (Dec 6, 2011)

hi vennwood, i have nothing that works on 24v only 12v as the invertor takes it down to 12v but you might have hit the nail when you said about not much output from the solar panel. cheers bluie


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## bluie (Dec 6, 2011)

hi kev n liz, thanks for the advice, i think your right i'll let a sparky sort it before i get my fingers burnt. as for pictures well thats another problem lol i,m the worlds worst with a pc, one finger job and all that, i will get there one day, i've got dozens of photos. regards bluie


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## Vennwood (Feb 4, 2007)

bluie said:


> hi vennwood, i have nothing that works on 24v only 12v as the invertor takes it down to 12v but you might have hit the nail when you said about not much output from the solar panel. cheers bluie


If you have nothing working on 24 volts AND the engine doesn't charge the batteries then it would be a simple task to switch over to 12 volts. When you say the inverter takes it down to 12 volts what do you mean? It seems odd, not to mention wasteful if you are using an inverter to drop the voltage from 24 to 12 as the inverter itself will take a small amount of power


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## bluie (Dec 6, 2011)

hi vennwood, well the truck is in open air storage at the moment so nothing is working, i have taken the engine batteries off the truck and have them in a garage on trickle charge, so the only charge the leisure batteries are getting is from the solar panel and it looks as its not enough. i thought the inverter just changed the voltage from 24v to 12v maybe i'm wrong. regards bluie


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## Vennwood (Feb 4, 2007)

bluie said:


> hi vennwood, well the truck is in open air storage at the moment so nothing is working, i have taken the engine batteries off the truck and have them in a garage on trickle charge, so the only charge the leisure batteries are getting is from the solar panel and it looks as its not enough. i thought the inverter just changed the voltage from 24v to 12v maybe i'm wrong. regards bluie


You haven't said what size panels you have but it this time of year with our current weather our panels are only putting up less than 5 amps a day and we have 434W worth


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## bluie (Dec 6, 2011)

hi vennwood, sorry i can't remember the output of the panels but there is two rather large one's on the roof, but the batteries have 800amp each so they will take a lot to keep them topped up so maybe they are not getting enough juice. bluie


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## Vennwood (Feb 4, 2007)

bluie said:


> hi vennwood, sorry i can't remember the output of the panels but there is two rather large one's on the roof, but the batteries have 800amp each so they will take a lot to keep them topped up so maybe they are not getting enough juice. bluie


When you say 800 amp each are you using the cold cranking amps or AH load - what size are they?

800 AH batteries must be massive and weigh a ton each


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## bluie (Dec 6, 2011)

yes vennwood they do 25kg each and ah, they are trojen batteries made in the usa. there about 18'' wide and 24'' high i can't lift them lol bluie


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## bluie (Dec 6, 2011)

hi ken-n-liz, your wish is my command, iv'e put a few photo's in the my album in the owners motorhomes page if you want to have a look, hope you enjoy, i have some more that i will put in there at a later date. regards bluie


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## Vennwood (Feb 4, 2007)

bluie said:


> yes vennwood they do 25kg each and ah, they are trojen batteries made in the usa. there about 18'' wide and 24'' high i can't lift them lol bluie


25kgs isn't very heavy nor is 18 x 24 that big given they are 800 AH - I had a 160 AH battery and that weighed 62gks

If its American maybe they measure their output differently to ours - are there any markings/ descriptions etc. on the sides?

Our "lightweight" 220 AH Elecsols weigh over 42GKS


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## cabby (May 14, 2005)

Reading your post,you have 4 x6 volt batteries all linked up in series, which gives you 24volts. If you split them into pairs and connect them in parallel it will give you 2x 12volts. very similar to the early MGB cars.Or in other words a set up equivelant to 2x12 volt batteries.you can them sort out the charging sequence needed.

do I take it that clivem is on holiday. :lol: :lol:

http://batteryuniversity.com/learn/article/serial_and_parallel_battery_configurations

cabby


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## Vennwood (Feb 4, 2007)

Just looked up Trojan Batteries on the web and it looks like they measure their batteries differently from the way Europeans do so as a wild guess I would think that the European equivalent of yours would be around a 250 amp battery - so 4 x 6 volt configured to 12 volt would be around 500 AH. I'm sure some techies will put me right on the exact output etc. 

But this is all some what irrelevant as I said earlier and as others have mentioned with batteries of that size/power you will need a heck of a lot of solar in winter to keep them charged up so you ought to consider installing a charger linked into the EHU so if necessary you can call on a campsite and plug in for a day or so or use a portable genny to charge them up. 

IMO - Solar will not cope on its own in this country in winter even if you have at least 500W of panels - you need another source of charging.


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## Pudsey_Bear (Sep 25, 2008)

bluie said:


> hi kev n liz, thanks for the advice, i think your right i'll let a sparky sort it before i get my fingers burnt. as for pictures well thats another problem lol i,m the worlds worst with a pc, one finger job and all that, i will get there one day, i've got dozens of photos. regards bluie


I looked for your pictures but for some reason couldn't find them.

As for charging I'm sure it wouldn't be too difficult to link the batteries and drop the output down to 12v after the 24v batteries with a resistor of some sort, I know what I mean but the worms won't come :evil: :evil: :evil:


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## bluie (Dec 6, 2011)

hi vennwood, don't forget they are 6volt so that a lot of volts 3200 in all numbers on batteries can be cross referaced, as i have bags of room i could pick which batteries i wanted from my work[motor factors at 50 o/o off. bluie


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## bluie (Dec 6, 2011)

hi kev_n_liz thanks for your input cheers if you would like to see my truck go to= members motorhomes then scroll down to album actions and then click on latest updates. good luck bluie


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## Vennwood (Feb 4, 2007)

bluie said:


> hi vennwood, don't forget they are 6volt so that a lot of volts 3200 in all numbers on batteries can be cross referaced, as i have bags of room i could pick which batteries i wanted from my work[motor factors at 50 o/o off. bluie


Sorry you have lost me here - "don't forget they are 6volt so that a lot of volts 3200" - what does that mean?


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## bluie (Dec 6, 2011)

hi vennwood sorry i talking drivel 800ah total, and yes they will a bit of charging, i have a small honda genny maybe i could charge them from that. bluie


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## Vennwood (Feb 4, 2007)

From memory the Honda will give you around 8 amps output at 12 volts - it won't do 24 volts. You could get a 30 amp charger from eBay or a motorist discount shop (your employer even) and that would help as you could use the Honda for both 12 volts and 240 volts thus putting (if you got a 30 amp charger) up to 38 amps into your battery bank in an hour


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## bluie (Dec 6, 2011)

thanks vennwood that or charge two at a time, i will have to work something out soon. cheers bluie


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## Pudsey_Bear (Sep 25, 2008)

bluie said:


> hi kev_n_liz thanks for your input cheers if you would like to see my truck go to= members motorhomes then scroll down to album actions and then click on latest updates. good luck bluie


I think I must be losing it Bluie, I still can't find members motorhomes, i assume it's under one of the tabs at the top of the screen, maybe it's not visible in Google Chrome.


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## Pudsey_Bear (Sep 25, 2008)

bluie said:


> hi kev_n_liz thanks for your input cheers if you would like to see my truck go to= members motorhomes then scroll down to album actions and then click on latest updates. good luck bluie


found it, cheers mate


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