Search found 401 matches

by Jeremy
Mon Apr 11, 2011 8:42 pm
Forum: All things battery related
Topic: watt hours / amp hours
Replies: 11
Views: 16778

Re: watt hours / amp hours

Lithium chemistry cells pretty much deliver all of their capacity as usable capacity, although their life is extended if discharge is limited to around 80% of maximum capacity. In general, the usable capacity of lithium cells is around 30% or so more than lead acid cells of the same capacity, plus t...
by Jeremy
Mon Apr 11, 2011 7:00 pm
Forum: All things battery related
Topic: watt hours / amp hours
Replies: 11
Views: 16778

Re: watt hours / amp hours

Pretty much, yes, but bear in mind that there may be some difference in usable power from different battery configurations. The key thing is to try and get hold of the discharge data for each battery type you're considering and see which will have the greatest usable capacity under the average disch...
by Jeremy
Mon Apr 11, 2011 5:34 pm
Forum: All things battery related
Topic: watt hours / amp hours
Replies: 11
Views: 16778

Re: watt hours / amp hours

Generally it's always best to compare battery packs in terms of watt hours, rather than amp hours, as this allows a fairer comparison of the actual stored power in the pack. Four 12V 200 Ah batteries connected in series will give you 48V at 200Ah, so 9,600Wh (4 x 12V x 200Ah = 9,600Wh) Eight 6V 200A...
by Jeremy
Sat Apr 09, 2011 8:03 pm
Forum: Cars,Vans and other road vehicles
Topic: buying a reva opinions
Replies: 9
Views: 16382

Re: buying a reva opinions

Perhaps a little bit of a balanced perspective is required here. I can fully understand the enthusiasm for the Berlingo, but let's face it, it is an antiquated, unreliable, very expensive and unsupported vehicle. One quick glance at the posts here detailing the myriad of Berlingo problems and the ve...
by Jeremy
Sun Apr 03, 2011 6:39 pm
Forum: Cars,Vans and other road vehicles
Topic: chinese electric cars
Replies: 6
Views: 12519

Re: chinese electric cars

As always, it depends on the level of understanding of the regs and the way that they are applied. If you buy a car blindly, without even a basic understanding of what will be needed to get it approved and registered, then the chances are you'll be disappointed when you run into the myriad of rules ...
by Jeremy
Sat Apr 02, 2011 10:37 am
Forum: Cars,Vans and other road vehicles
Topic: chinese electric cars
Replies: 6
Views: 12519

Re: chinese electric cars

I did enquire about one that was registered and the owner/importer had just put it through SVA in the usual way. A lot depends on the weight of the car, as the lighter ones (like the G-Wiz) can go through as quadracycles and avoid some of the more onerous stuff. To be honest I can't really see it be...
by Jeremy
Fri Apr 01, 2011 7:01 pm
Forum: Cars,Vans and other road vehicles
Topic: chinese electric cars
Replies: 6
Views: 12519

Re: chinese electric cars

There was one for sale on ebay a year or so ago that someone had imported as a one-off, so it can be done. I think you pretty much get what you pay for, in terms of quality, fit, finish etc but as the basis for a project they might be worth it. Shipping might not be too expensive, as two would fit i...
by Jeremy
Tue Mar 29, 2011 8:31 am
Forum: All things battery related
Topic: Hobbyking RC batteries
Replies: 3
Views: 7140

Re: Hobbyking RC batteries

Charging is a bit of a pain, but pretty much any RC Lipo balance charger will work fine. It depends how fast you want to recharge the packs and what size packs you choose to use, as some chargers only have a 5S or 6S upper limit (although some of the top end ones will now charge 10S. HK wouldn't be ...
by Jeremy
Mon Mar 28, 2011 10:00 pm
Forum: All things battery related
Topic: Hobbyking RC batteries
Replies: 3
Views: 7140

Re: Hobbyking RC batteries

I've bought loads of LiPos from HK and found them generally pretty good to deal with. There aren't many English speakers there though, plus there's a big time difference, so it can take a day or two to get an answer (you will probably get a reply eventually, depending on the nature of your question,...
by Jeremy
Thu Mar 24, 2011 9:14 am
Forum: All things battery related
Topic: Think I've overfilled my VRLAs
Replies: 16
Views: 15909

Re: Think I've overfilled my VRLAs

I bought a batch of Headway cells direct from Headway and found them fine to deal with. The only slight issue was having to pay by bank transfer, but that went well. Delivery was quick, too. I think if I was looking to replace the lead acid batteries for a relatively high power application like this...

Go to advanced search