[Kustom55]

What I am missing.Why are the battery supplies so expensive? Can't I just use (2) 12 volt 75ah batteries in parallel and charge them with a regular 24V charger?Or is there more to this that I am missing?Are there other circuits involved?

[Guy 13]

What I am missing.Why are the battery supplies so expensive? Can't I just use (2) 12 volt 75ah batteries in parallel and charge them with a regular 24V charger?Or is there more to this that I am missing?Are there other circuits involved?

Hi Kustom 55
You mean two 12 volts batteries in series to get 24 volts and then charge them with a 24 volts charger !
By the way, I don't think you are missing anything, the only circuit involved would by for/with/in the charger to limit over charging and/or stabilize the voltage.
Any one disagree with me ?
Guy 13.

[virtue]

If your own time is cheap, you can probably justify building your own battery kit.  The problem is that most chargers out there make noise when left plugged into the circuit.  The good ones are more expensive: we recommend Soneil or PowerStream chargers. 

The only catastrophic gotchas are to make sure that the center-pin on your 2.1mm ID x 5.5 mm OD jack is positive and to use a 2010 amp with an internal soft-start.

For most customers, it's cheaper and easier to buy from us but the choice is yours!  Gary does a great job and puts a fuse in there for good measure.

[dvenardos]

Yeah, when you start adding up all the parts is when it gets expensive, but you can definitely do it cheaper yourself just not as nice as Gary (unless you are good).

[Kustom55]

 :oops:Yes I meant 2 in series. I was only asking because I do have many used but good 12 volt 75AH batteries that i send to recycle at work.Don't get me wrong the products sold are very nice , but I'll try to make a nice one first and if it looks like hell, then I'll buy one. I also just picked up 3 mean well power supplies rated at 24-27V 31 amps pretty nice. Has anyone tried these before?Thanks Ed

[dvenardos]

Yeah, if you already have the batteries then go for it. 

The meanwell are supposed to be good. Let us know how they sound as you can get them for pretty cheap.

[dba]

Has anyone tried 30v battery setup, 12v+6v+12v...?

[saisunil]

I was thinking along smilar lines ... can we get more than 24V from batteries that would be safe / compatible with Sensation - for more power?
 

Has anyone tried 30v battery setup, 12v+6v+12v...?

[mikeeastman]

12+12+6 will give you actual voltages of 32-33V or higher, especially during charging and I think that is higher than Seth recommends.

[Speedskater]

In any case, I think that all the batteries should be the same model number. As different types or voltage batteries would have different discharge rates.

[Norman Tracy]

When DIYing battery supplies PLEASE FUSE THE BATTERIES! 

I've watched 12VDC battery packs of the size being discussed here turn several inches of a 22AWG wire into a fuse when the connector short circuited the battery. It is quite a show, first the insulation burns off, then the copper wire glows bright red, then the wire vaporizes.  All before anyone can get across the lab to disconnect. Just as well as one should be heading away when this happens.

Remember, as long as one stays below 48VDC one is generally considered safe from electrocution. BUT SLA batteries can dump 10s even 100s of amps of current into low impedances so one needs to stay aware of the burn hazards.

[se-riously]

12+12+6 will give you actual voltages of 32-33V or higher, especially during charging and I think that is higher than Seth recommends.

A 12+12+4 SLA combination will give you a fully charged 30.1 volts.  Both 4v and 12v batteries come in 10Ah versions.  So this might be an option, but you'd probably have to charge the two 12v batteries with a 24v charger, the 4v with its own charger, and disconnect/reconnect everything during the charging cycle.

[saisunil]

good point ...
so how does RWA serve up 30V - or does it?
 
For my needs - I need to give more juice to Sensation than 24V ... how can I do that ...
 

[TRADERXFAN]

rwa 30 watts, just 12v.

[saisunil]

I meant RWA black lightening battery packs ... they are just too pricey for me ...

[se-riously]

I don't know what voltage RWA serves up, but their standard version uses SLA's, so I would expect the same voltage as the DIY kit.  If you want to save money, just get the DIY kit from Virtue that will deliver around 25.8 volts.  You could technically build it yourself slightly less, but you'll have to find a high quality charger like the Soneil that's included in the kit. 

The RWA LiFePO4 version supposedly adds benefits from lower impedance and (I suspect) delivers either somewhere around 25.6v - 28.8v.

[saisunil]

I have dodd's battery kit that I got from virtue - I just need more headroom ...